Guile-OpenGL: Low-Level GL

3.6 Low-Level GL

The functions from this section may be had by loading the module:

(use-modules (gl low-level)

This section of the manual was derived from the upstream OpenGL documentation. Each function’s documentation has its own copyright statement; for full details, see the upstream documentation. The copyright notices and licenses present in this section are as follows.

Copyright © 2003-2005 3Dlabs Inc. Ltd. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.

Function: void glAccum op value

Operate on the accumulation buffer.

op: Specifies the accumulation buffer operation. Symbolic constants GL_ACCUM, GL_LOAD, GL_ADD, GL_MULT, and GL_RETURN are accepted.
value: Specifies a floating-point value used in the accumulation buffer operation. op determines how value is used.

The accumulation buffer is an extended-range color buffer. Images are not rendered into it. Rather, images rendered into one of the color buffers are added to the contents of the accumulation buffer after rendering. Effects such as antialiasing (of points, lines, and polygons), motion blur, and depth of field can be created by accumulating images generated with different transformation matrices.

Each pixel in the accumulation buffer consists of red, green, blue, and alpha values. The number of bits per component in the accumulation buffer depends on the implementation. You can examine this number by calling glGetIntegerv four times, with arguments GL_ACCUM_RED_BITS, GL_ACCUM_GREEN_BITS, GL_ACCUM_BLUE_BITS, and GL_ACCUM_ALPHA_BITS. Regardless of the number of bits per component, the range of values stored by each component is [-1,1]. The accumulation buffer pixels are mapped one-to-one with frame buffer pixels.

glAccum operates on the accumulation buffer. The first argument, op, is a symbolic constant that selects an accumulation buffer operation. The second argument, value, is a floating-point value to be used in that operation. Five operations are specified: GL_ACCUM, GL_LOAD, GL_ADD, GL_MULT, and GL_RETURN.

All accumulation buffer operations are limited to the area of the current scissor box and applied identically to the red, green, blue, and alpha components of each pixel. If a glAccum operation results in a value outside the range [-1,1], the contents of an accumulation buffer pixel component are undefined.

The operations are as follows:

GL_ACCUM: Obtains R, G, B, and A values from the buffer currently selected for reading (see glReadBuffer). Each component value is divided by 2^n-1, where n is the number of bits allocated to each color component in the currently selected buffer. The result is a floating-point value in the range [0,1], which is multiplied by value and added to the corresponding pixel component in the accumulation buffer, thereby updating the accumulation buffer.
GL_LOAD: Similar to GL_ACCUM, except that the current value in the accumulation buffer is not used in the calculation of the new value. That is, the R, G, B, and A values from the currently selected buffer are divided by 2^n-1, multiplied by value, and then stored in the corresponding accumulation buffer cell, overwriting the current value.
GL_ADD: Adds value to each R, G, B, and A in the accumulation buffer.
GL_MULT: Multiplies each R, G, B, and A in the accumulation buffer by value and returns the scaled component to its corresponding accumulation buffer location.
GL_RETURN: Transfers accumulation buffer values to the color buffer or buffers currently selected for writing. Each R, G, B, and A component is multiplied by value, then multiplied by 2^n-1, clamped to the range [0,2^n-1], and stored in the corresponding display buffer cell. The only fragment operations that are applied to this transfer are pixel ownership, scissor, dithering, and color writemasks.

To clear the accumulation buffer, call glClearAccum with R, G, B, and A values to set it to, then call glClear with the accumulation buffer enabled.

GL_INVALID_ENUM is generated if op is not an accepted value.

GL_INVALID_OPERATION is generated if there is no accumulation buffer.

GL_INVALID_OPERATION is generated if glAccum is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glActiveTexture texture

Select active texture unit.

texture: Specifies which texture unit to make active. The number of texture units is implementation dependent, but must be at least two. texture must be one of GL_TEXTUREi, where i ranges from 0 to the larger of (GL_MAX_TEXTURE_COORDS - 1) and (GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS - 1). The initial value is GL_TEXTURE0.

glActiveTexture selects which texture unit subsequent texture state calls will affect. The number of texture units an implementation supports is implementation dependent, but must be at least 2.

Vertex arrays are client-side GL resources, which are selected by the glClientActiveTexture routine.

GL_INVALID_ENUM is generated if texture is not one of GL_TEXTUREi, where i ranges from 0 to the larger of (GL_MAX_TEXTURE_COORDS - 1) and (GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS - 1).

Function: void glAlphaFunc func ref

Specify the alpha test function.

func: Specifies the alpha comparison function. Symbolic constants GL_NEVER, GL_LESS, GL_EQUAL, GL_LEQUAL, GL_GREATER, GL_NOTEQUAL, GL_GEQUAL, and GL_ALWAYS are accepted. The initial value is GL_ALWAYS.
ref: Specifies the reference value that incoming alpha values are compared to. This value is clamped to the range [0,1], where 0 represents the lowest possible alpha value and 1 the highest possible value. The initial reference value is 0.

The alpha test discards fragments depending on the outcome of a comparison between an incoming fragment’s alpha value and a constant reference value. glAlphaFunc specifies the reference value and the comparison function. The comparison is performed only if alpha testing is enabled. By default, it is not enabled. (See glEnable and glDisable of GL_ALPHA_TEST.)

func and ref specify the conditions under which the pixel is drawn. The incoming alpha value is compared to ref using the function specified by func. If the value passes the comparison, the incoming fragment is drawn if it also passes subsequent stencil and depth buffer tests. If the value fails the comparison, no change is made to the frame buffer at that pixel location. The comparison functions are as follows:

GL_NEVER: Never passes.
GL_LESS: Passes if the incoming alpha value is less than the reference value.
GL_EQUAL: Passes if the incoming alpha value is equal to the reference value.
GL_LEQUAL: Passes if the incoming alpha value is less than or equal to the reference value.
GL_GREATER: Passes if the incoming alpha value is greater than the reference value.
GL_NOTEQUAL: Passes if the incoming alpha value is not equal to the reference value.
GL_GEQUAL: Passes if the incoming alpha value is greater than or equal to the reference value.
GL_ALWAYS: Always passes (initial value).

glAlphaFunc operates on all pixel write operations, including those resulting from the scan conversion of points, lines, polygons, and bitmaps, and from pixel draw and copy operations. glAlphaFunc does not affect screen clear operations.

GL_INVALID_ENUM is generated if func is not an accepted value.

GL_INVALID_OPERATION is generated if glAlphaFunc is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLboolean glAreTexturesResident n textures residences

Determine if textures are loaded in texture memory.

n: Specifies the number of textures to be queried.
textures: Specifies an array containing the names of the textures to be queried.
residences: Specifies an array in which the texture residence status is returned. The residence status of a texture named by an element of textures is returned in the corresponding element of residences.

GL establishes a “working set” of textures that are resident in texture memory. These textures can be bound to a texture target much more efficiently than textures that are not resident.

glAreTexturesResident queries the texture residence status of the n textures named by the elements of textures. If all the named textures are resident, glAreTexturesResident returns GL_TRUE, and the contents of residences are undisturbed. If not all the named textures are resident, glAreTexturesResident returns GL_FALSE, and detailed status is returned in the n elements of residences. If an element of residences is GL_TRUE, then the texture named by the corresponding element of textures is resident.

The residence status of a single bound texture may also be queried by calling glGetTexParameter with the target argument set to the target to which the texture is bound, and the pname argument set to GL_TEXTURE_RESIDENT. This is the only way that the residence status of a default texture can be queried.

GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_VALUE is generated if any element in textures is 0 or does not name a texture. In that case, the function returns GL_FALSE and the contents of residences is indeterminate.

GL_INVALID_OPERATION is generated if glAreTexturesResident is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glArrayElement i

Render a vertex using the specified vertex array element.

i: Specifies an index into the enabled vertex data arrays.

glArrayElement commands are used within glBegin/glEnd pairs to specify vertex and attribute data for point, line, and polygon primitives. If GL_VERTEX_ARRAY is enabled when glArrayElement is called, a single vertex is drawn, using vertex and attribute data taken from location i of the enabled arrays. If GL_VERTEX_ARRAY is not enabled, no drawing occurs but the attributes corresponding to the enabled arrays are modified.

Use glArrayElement to construct primitives by indexing vertex data, rather than by streaming through arrays of data in first-to-last order. Because each call specifies only a single vertex, it is possible to explicitly specify per-primitive attributes such as a single normal for each triangle.

Changes made to array data between the execution of glBegin and the corresponding execution of glEnd may affect calls to glArrayElement that are made within the same glBegin/glEnd period in nonsequential ways. That is, a call to glArrayElement that precedes a change to array data may access the changed data, and a call that follows a change to array data may access original data.

GL_INVALID_VALUE may be generated if i is negative.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array and the buffer object’s data store is currently mapped.

Function: void glAttachShader program shader

Attaches a shader object to a program object.

program: Specifies the program object to which a shader object will be attached.
shader: Specifies the shader object that is to be attached.

In order to create an executable, there must be a way to specify the list of things that will be linked together. Program objects provide this mechanism. Shaders that are to be linked together in a program object must first be attached to that program object. glAttachShader attaches the shader object specified by shader to the program object specified by program. This indicates that shader will be included in link operations that will be performed on program.

All operations that can be performed on a shader object are valid whether or not the shader object is attached to a program object. It is permissible to attach a shader object to a program object before source code has been loaded into the shader object or before the shader object has been compiled. It is permissible to attach multiple shader objects of the same type because each may contain a portion of the complete shader. It is also permissible to attach a shader object to more than one program object. If a shader object is deleted while it is attached to a program object, it will be flagged for deletion, and deletion will not occur until glDetachShader is called to detach it from all program objects to which it is attached.

GL_INVALID_VALUE is generated if either program or shader is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_OPERATION is generated if shader is not a shader object.

GL_INVALID_OPERATION is generated if shader is already attached to program.

GL_INVALID_OPERATION is generated if glAttachShader is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBeginQuery target id

Function: void glEndQuery target

Delimit the boundaries of a query object.

target: Specifies the target type of query object established between glBeginQuery and the subsequent glEndQuery. The symbolic constant must be GL_SAMPLES_PASSED.
id: Specifies the name of a query object.

glBeginQuery and glEndQuery delimit the boundaries of a query object. If a query object with name id does not yet exist it is created.

When glBeginQuery is executed, the query object’s samples-passed counter is reset to 0. Subsequent rendering will increment the counter once for every sample that passes the depth test. When glEndQuery is executed, the samples-passed counter is assigned to the query object’s result value. This value can be queried by calling glGetQueryObject with pnameGL_QUERY_RESULT.

Querying the GL_QUERY_RESULT implicitly flushes the GL pipeline until the rendering delimited by the query object has completed and the result is available. GL_QUERY_RESULT_AVAILABLE can be queried to determine if the result is immediately available or if the rendering is not yet complete.

GL_INVALID_ENUM is generated if target is not GL_SAMPLES_PASSED.

GL_INVALID_OPERATION is generated if glBeginQuery is executed while a query object of the same target is already active.

GL_INVALID_OPERATION is generated if glEndQuery is executed when a query object of the same target is not active.

GL_INVALID_OPERATION is generated if id is 0.

GL_INVALID_OPERATION is generated if id is the name of an already active query object.

GL_INVALID_OPERATION is generated if glBeginQuery or glEndQuery is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBegin mode

Function: void glEnd

Delimit the vertices of a primitive or a group of like primitives.

mode: Specifies the primitive or primitives that will be created from vertices presented between glBegin and the subsequent glEnd. Ten symbolic constants are accepted: GL_POINTS, GL_LINES, GL_LINE_STRIP, GL_LINE_LOOP, GL_TRIANGLES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_QUADS, GL_QUAD_STRIP, and GL_POLYGON.

glBegin and glEnd delimit the vertices that define a primitive or a group of like primitives. glBegin accepts a single argument that specifies in which of ten ways the vertices are interpreted. Taking n as an integer count starting at one, and N as the total number of vertices specified, the interpretations are as follows:

GL_POINTS: Treats each vertex as a single point. Vertex n defines point n. N points are drawn.
GL_LINES: Treats each pair of vertices as an independent line segment. Vertices 2â¢n-1 and 2â¢n define line n. N/2 lines are drawn.
GL_LINE_STRIP: Draws a connected group of line segments from the first vertex to the last. Vertices n and n+1 define line n. N-1 lines are drawn.
GL_LINE_LOOP: Draws a connected group of line segments from the first vertex to the last, then back to the first. Vertices n and n+1 define line n. The last line, however, is defined by vertices N and 1. N lines are drawn.
GL_TRIANGLES: Treats each triplet of vertices as an independent triangle. Vertices 3â¢n-2, 3â¢n-1, and 3â¢n define triangle n. N/3 triangles are drawn.
GL_TRIANGLE_STRIP: Draws a connected group of triangles. One triangle is defined for each vertex presented after the first two vertices. For odd n, vertices n, n+1, and n+2 define triangle n. For even n, vertices n+1, n, and n+2 define triangle n. N-2 triangles are drawn.
GL_TRIANGLE_FAN: Draws a connected group of triangles. One triangle is defined for each vertex presented after the first two vertices. Vertices 1, n+1, and n+2 define triangle n. N-2 triangles are drawn.
GL_QUADS: Treats each group of four vertices as an independent quadrilateral. Vertices 4â¢n-3, 4â¢n-2, 4â¢n-1, and 4â¢n define quadrilateral n. N/4 quadrilaterals are drawn.
GL_QUAD_STRIP: Draws a connected group of quadrilaterals. One quadrilateral is defined for each pair of vertices presented after the first pair. Vertices 2â¢n-1, 2â¢n, 2â¢n+2, and 2â¢n+1 define quadrilateral n. N/2-1 quadrilaterals are drawn. Note that the order in which vertices are used to construct a quadrilateral from strip data is different from that used with independent data.
GL_POLYGON: Draws a single, convex polygon. Vertices 1 through N define this polygon.

Only a subset of GL commands can be used between glBegin and glEnd. The commands are glVertex, glColor, glSecondaryColor, glIndex, glNormal, glFogCoord, glTexCoord, glMultiTexCoord, glVertexAttrib, glEvalCoord, glEvalPoint, glArrayElement, glMaterial, and glEdgeFlag. Also, it is acceptable to use glCallList or glCallLists to execute display lists that include only the preceding commands. If any other GL command is executed between glBegin and glEnd, the error flag is set and the command is ignored.

Regardless of the value chosen for mode, there is no limit to the number of vertices that can be defined between glBegin and glEnd. Lines, triangles, quadrilaterals, and polygons that are incompletely specified are not drawn. Incomplete specification results when either too few vertices are provided to specify even a single primitive or when an incorrect multiple of vertices is specified. The incomplete primitive is ignored; the rest are drawn.

The minimum specification of vertices for each primitive is as follows: 1 for a point, 2 for a line, 3 for a triangle, 4 for a quadrilateral, and 3 for a polygon. Modes that require a certain multiple of vertices are GL_LINES (2), GL_TRIANGLES (3), GL_QUADS (4), and GL_QUAD_STRIP (2).

GL_INVALID_ENUM is generated if mode is set to an unaccepted value.

GL_INVALID_OPERATION is generated if glBegin is executed between a glBegin and the corresponding execution of glEnd.

GL_INVALID_OPERATION is generated if glEnd is executed without being preceded by a glBegin.

GL_INVALID_OPERATION is generated if a command other than glVertex, glColor, glSecondaryColor, glIndex, glNormal, glFogCoord, glTexCoord, glMultiTexCoord, glVertexAttrib, glEvalCoord, glEvalPoint, glArrayElement, glMaterial, glEdgeFlag, glCallList, or glCallLists is executed between the execution of glBegin and the corresponding execution glEnd.

Execution of glEnableClientState, glDisableClientState, glEdgeFlagPointer, glFogCoordPointer, glTexCoordPointer, glColorPointer, glSecondaryColorPointer, glIndexPointer, glNormalPointer, glVertexPointer, glVertexAttribPointer, glInterleavedArrays, or glPixelStore is not allowed after a call to glBegin and before the corresponding call to glEnd, but an error may or may not be generated.

Function: void glBindAttribLocation program index name

Associates a generic vertex attribute index with a named attribute variable.

program: Specifies the handle of the program object in which the association is to be made.
index: Specifies the index of the generic vertex attribute to be bound.
name: Specifies a null terminated string containing the name of the vertex shader attribute variable to which index is to be bound.

glBindAttribLocation is used to associate a user-defined attribute variable in the program object specified by program with a generic vertex attribute index. The name of the user-defined attribute variable is passed as a null terminated string in name. The generic vertex attribute index to be bound to this variable is specified by index. When program is made part of current state, values provided via the generic vertex attribute index will modify the value of the user-defined attribute variable specified by name.

If name refers to a matrix attribute variable, index refers to the first column of the matrix. Other matrix columns are then automatically bound to locations index+1 for a matrix of type mat2; index+1 and index+2 for a matrix of type mat3; and index+1, index+2, and index+3 for a matrix of type mat4.

This command makes it possible for vertex shaders to use descriptive names for attribute variables rather than generic variables that are numbered from 0 to GL_MAX_VERTEX_ATTRIBS -1. The values sent to each generic attribute index are part of current state, just like standard vertex attributes such as color, normal, and vertex position. If a different program object is made current by calling glUseProgram, the generic vertex attributes are tracked in such a way that the same values will be observed by attributes in the new program object that are also bound to index.

Attribute variable name-to-generic attribute index bindings for a program object can be explicitly assigned at any time by calling glBindAttribLocation. Attribute bindings do not go into effect until glLinkProgram is called. After a program object has been linked successfully, the index values for generic attributes remain fixed (and their values can be queried) until the next link command occurs.

Applications are not allowed to bind any of the standard OpenGL vertex attributes using this command, as they are bound automatically when needed. Any attribute binding that occurs after the program object has been linked will not take effect until the next time the program object is linked.

GL_INVALID_VALUE is generated if index is greater than or equal to GL_MAX_VERTEX_ATTRIBS.

GL_INVALID_OPERATION is generated if name starts with the reserved prefix "gl_".

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_OPERATION is generated if glBindAttribLocation is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBindBuffer target buffer

Bind a named buffer object.

target: Specifies the target to which the buffer object is bound. The symbolic constant must be GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.
buffer: Specifies the name of a buffer object.

glBindBuffer lets you create or use a named buffer object. Calling glBindBuffer with target set to GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER or GL_PIXEL_UNPACK_BUFFER and buffer set to the name of the new buffer object binds the buffer object name to the target. When a buffer object is bound to a target, the previous binding for that target is automatically broken.

Buffer object names are unsigned integers. The value zero is reserved, but there is no default buffer object for each buffer object target. Instead, buffer set to zero effectively unbinds any buffer object previously bound, and restores client memory usage for that buffer object target. Buffer object names and the corresponding buffer object contents are local to the shared display-list space (see glXCreateContext) of the current GL rendering context; two rendering contexts share buffer object names only if they also share display lists.

You may use glGenBuffers to generate a set of new buffer object names.

The state of a buffer object immediately after it is first bound is an unmapped zero-sized memory buffer with GL_READ_WRITE access and GL_STATIC_DRAW usage.

While a non-zero buffer object name is bound, GL operations on the target to which it is bound affect the bound buffer object, and queries of the target to which it is bound return state from the bound buffer object. While buffer object name zero is bound, as in the initial state, attempts to modify or query state on the target to which it is bound generates an GL_INVALID_OPERATION error.

When vertex array pointer state is changed, for example by a call to glNormalPointer, the current buffer object binding (GL_ARRAY_BUFFER_BINDING) is copied into the corresponding client state for the vertex array type being changed, for example GL_NORMAL_ARRAY_BUFFER_BINDING. While a non-zero buffer object is bound to the GL_ARRAY_BUFFER target, the vertex array pointer parameter that is traditionally interpreted as a pointer to client-side memory is instead interpreted as an offset within the buffer object measured in basic machine units.

While a non-zero buffer object is bound to the GL_ELEMENT_ARRAY_BUFFER target, the indices parameter of glDrawElements, glDrawRangeElements, or glMultiDrawElements that is traditionally interpreted as a pointer to client-side memory is instead interpreted as an offset within the buffer object measured in basic machine units.

While a non-zero buffer object is bound to the GL_PIXEL_PACK_BUFFER target, the following commands are affected: glGetCompressedTexImage, glGetConvolutionFilter, glGetHistogram, glGetMinmax, glGetPixelMap, glGetPolygonStipple, glGetSeparableFilter, glGetTexImage, and glReadPixels. The pointer parameter that is traditionally interpreted as a pointer to client-side memory where the pixels are to be packed is instead interpreted as an offset within the buffer object measured in basic machine units.

While a non-zero buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target, the following commands are affected: glBitmap, glColorSubTable, glColorTable, glCompressedTexImage1D, glCompressedTexImage2D, glCompressedTexImage3D, glCompressedTexSubImage1D, glCompressedTexSubImage2D, glCompressedTexSubImage3D, glConvolutionFilter1D, glConvolutionFilter2D, glDrawPixels, glPixelMap, glPolygonStipple, glSeparableFilter2D, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, and glTexSubImage3D. The pointer parameter that is traditionally interpreted as a pointer to client-side memory from which the pixels are to be unpacked is instead interpreted as an offset within the buffer object measured in basic machine units.

A buffer object binding created with glBindBuffer remains active until a different buffer object name is bound to the same target, or until the bound buffer object is deleted with glDeleteBuffers.

Once created, a named buffer object may be re-bound to any target as often as needed. However, the GL implementation may make choices about how to optimize the storage of a buffer object based on its initial binding target.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_OPERATION is generated if glBindBuffer is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBindTexture target texture

Bind a named texture to a texturing target.

target: Specifies the target to which the texture is bound. Must be either GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, or GL_TEXTURE_CUBE_MAP.
texture: Specifies the name of a texture.

glBindTexture lets you create or use a named texture. Calling glBindTexture with target set to GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D or GL_TEXTURE_CUBE_MAP and texture set to the name of the new texture binds the texture name to the target. When a texture is bound to a target, the previous binding for that target is automatically broken.

Texture names are unsigned integers. The value zero is reserved to represent the default texture for each texture target. Texture names and the corresponding texture contents are local to the shared display-list space (see glXCreateContext) of the current GL rendering context; two rendering contexts share texture names only if they also share display lists.

You may use glGenTextures to generate a set of new texture names.

When a texture is first bound, it assumes the specified target: A texture first bound to GL_TEXTURE_1D becomes one-dimensional texture, a texture first bound to GL_TEXTURE_2D becomes two-dimensional texture, a texture first bound to GL_TEXTURE_3D becomes three-dimensional texture, and a texture first bound to GL_TEXTURE_CUBE_MAP becomes a cube-mapped texture. The state of a one-dimensional texture immediately after it is first bound is equivalent to the state of the default GL_TEXTURE_1D at GL initialization, and similarly for two- and three-dimensional textures and cube-mapped textures.

While a texture is bound, GL operations on the target to which it is bound affect the bound texture, and queries of the target to which it is bound return state from the bound texture. If texture mapping is active on the target to which a texture is bound, the bound texture is used. In effect, the texture targets become aliases for the textures currently bound to them, and the texture name zero refers to the default textures that were bound to them at initialization.

A texture binding created with glBindTexture remains active until a different texture is bound to the same target, or until the bound texture is deleted with glDeleteTextures.

Once created, a named texture may be re-bound to its same original target as often as needed. It is usually much faster to use glBindTexture to bind an existing named texture to one of the texture targets than it is to reload the texture image using glTexImage1D, glTexImage2D, or glTexImage3D. For additional control over performance, use glPrioritizeTextures.

glBindTexture is included in display lists.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_OPERATION is generated if texture was previously created with a target that doesn’t match that of target.

GL_INVALID_OPERATION is generated if glBindTexture is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBitmap width height xorig yorig xmove ymove bitmap

Draw a bitmap.

width
height: Specify the pixel width and height of the bitmap image.
xorig
yorig: Specify the location of the origin in the bitmap image. The origin is measured from the lower left corner of the bitmap, with right and up being the positive axes.
xmove
ymove: Specify the x and y offsets to be added to the current raster position after the bitmap is drawn.
bitmap: Specifies the address of the bitmap image.

A bitmap is a binary image. When drawn, the bitmap is positioned relative to the current raster position, and frame buffer pixels corresponding to 1’s in the bitmap are written using the current raster color or index. Frame buffer pixels corresponding to 0’s in the bitmap are not modified.

glBitmap takes seven arguments. The first pair specifies the width and height of the bitmap image. The second pair specifies the location of the bitmap origin relative to the lower left corner of the bitmap image. The third pair of arguments specifies x and y offsets to be added to the current raster position after the bitmap has been drawn. The final argument is a pointer to the bitmap image itself.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a bitmap image is specified, bitmap is treated as a byte offset into the buffer object’s data store.

The bitmap image is interpreted like image data for the glDrawPixels command, with width and height corresponding to the width and height arguments of that command, and with type set to GL_BITMAP and format set to GL_COLOR_INDEX. Modes specified using glPixelStore affect the interpretation of bitmap image data; modes specified using glPixelTransfer do not.

If the current raster position is invalid, glBitmap is ignored. Otherwise, the lower left corner of the bitmap image is positioned at the window coordinates

x_w=âx_r-x_o,â

y_w=ây_r-y_o,â

where (x_r,y_r) is the raster position and (x_o,y_o) is the bitmap origin. Fragments are then generated for each pixel corresponding to a 1 (one) in the bitmap image. These fragments are generated using the current raster z coordinate, color or color index, and current raster texture coordinates. They are then treated just as if they had been generated by a point, line, or polygon, including texture mapping, fogging, and all per-fragment operations such as alpha and depth testing.

After the bitmap has been drawn, the x and y coordinates of the current raster position are offset by xmove and ymove. No change is made to the z coordinate of the current raster position, or to the current raster color, texture coordinates, or index.

GL_INVALID_VALUE is generated if width or height is negative.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the data would be unpacked from the buffer object such that the memory reads required would exceed the data store size.

GL_INVALID_OPERATION is generated if glBitmap is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBlendColor red green blue alpha

Set the blend color.

red
green
blue
alpha: specify the components of GL_BLEND_COLOR

The GL_BLEND_COLOR may be used to calculate the source and destination blending factors. The color components are clamped to the range [0,1] before being stored. See glBlendFunc for a complete description of the blending operations. Initially the GL_BLEND_COLOR is set to (0, 0, 0, 0).

GL_INVALID_OPERATION is generated if glBlendColor is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBlendEquationSeparate modeRGB modeAlpha

Set the RGB blend equation and the alpha blend equation separately.

modeRGB: specifies the RGB blend equation, how the red, green, and blue components of the source and destination colors are combined. It must be GL_FUNC_ADD, GL_FUNC_SUBTRACT, GL_FUNC_REVERSE_SUBTRACT, GL_MIN, GL_MAX.
modeAlpha: specifies the alpha blend equation, how the alpha component of the source and destination colors are combined. It must be GL_FUNC_ADD, GL_FUNC_SUBTRACT, GL_FUNC_REVERSE_SUBTRACT, GL_MIN, GL_MAX.

The blend equations determines how a new pixel (the ”source” color) is combined with a pixel already in the framebuffer (the ”destination” color). This function specifies one blend equation for the RGB-color components and one blend equation for the alpha component.

The blend equations use the source and destination blend factors specified by either glBlendFunc or glBlendFuncSeparate. See glBlendFunc or glBlendFuncSeparate for a description of the various blend factors.

In the equations that follow, source and destination color components are referred to as (R_s,G_sB_sA_s) and (R_d,G_dB_dA_d), respectively. The result color is referred to as (R_r,G_rB_rA_r). The source and destination blend factors are denoted (s_R,s_Gs_Bs_A) and (d_R,d_Gd_Bd_A), respectively. For these equations all color components are understood to have values in the range [0,1].

Mode: RGB Components, Alpha Component
GL_FUNC_ADD: Rr=R_sâ¢s_R+R_dâ¢d_RGr=G_sâ¢s_G+G_dâ¢d_GBr=B_sâ¢s_B+B_dâ¢d_B, Ar=A_sâ¢s_A+A_dâ¢d_A
GL_FUNC_SUBTRACT: Rr=R_sâ¢s_R-R_dâ¢d_RGr=G_sâ¢s_G-G_dâ¢d_GBr=B_sâ¢s_B-B_dâ¢d_B, Ar=A_sâ¢s_A-A_dâ¢d_A
GL_FUNC_REVERSE_SUBTRACT: Rr=R_dâ¢d_R-R_sâ¢s_RGr=G_dâ¢d_G-G_sâ¢s_GBr=B_dâ¢d_B-B_sâ¢s_B, Ar=A_dâ¢d_A-A_sâ¢s_A
GL_MIN: Rr=minâ¡(R_s,R_d)Gr=minâ¡(G_s,G_d)Br=minâ¡(B_s,B_d), Ar=minâ¡(A_s,A_d)
GL_MAX: Rr=maxâ¡(R_s,R_d)Gr=maxâ¡(G_s,G_d)Br=maxâ¡(B_s,B_d), Ar=maxâ¡(A_s,A_d)

The results of these equations are clamped to the range [0,1].

The GL_MIN and GL_MAX equations are useful for applications that analyze image data (image thresholding against a constant color, for example). The GL_FUNC_ADD equation is useful for antialiasing and transparency, among other things.

Initially, both the RGB blend equation and the alpha blend equation are set to GL_FUNC_ADD.

GL_INVALID_ENUM is generated if either modeRGB or modeAlpha is not one of GL_FUNC_ADD, GL_FUNC_SUBTRACT, GL_FUNC_REVERSE_SUBTRACT, GL_MAX, or GL_MIN.

GL_INVALID_OPERATION is generated if glBlendEquationSeparate is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBlendEquation mode

Specify the equation used for both the RGB blend equation and the Alpha blend equation.

mode: specifies how source and destination colors are combined. It must be GL_FUNC_ADD, GL_FUNC_SUBTRACT, GL_FUNC_REVERSE_SUBTRACT, GL_MIN, GL_MAX.

The blend equations determine how a new pixel (the ”source” color) is combined with a pixel already in the framebuffer (the ”destination” color). This function sets both the RGB blend equation and the alpha blend equation to a single equation.

These equations use the source and destination blend factors specified by either glBlendFunc or glBlendFuncSeparate. See glBlendFunc or glBlendFuncSeparate for a description of the various blend factors.

Mode: RGB Components, Alpha Component
GL_FUNC_ADD: Rr=R_sâ¢s_R+R_dâ¢d_RGr=G_sâ¢s_G+G_dâ¢d_GBr=B_sâ¢s_B+B_dâ¢d_B, Ar=A_sâ¢s_A+A_dâ¢d_A
GL_FUNC_SUBTRACT: Rr=R_sâ¢s_R-R_dâ¢d_RGr=G_sâ¢s_G-G_dâ¢d_GBr=B_sâ¢s_B-B_dâ¢d_B, Ar=A_sâ¢s_A-A_dâ¢d_A
GL_FUNC_REVERSE_SUBTRACT: Rr=R_dâ¢d_R-R_sâ¢s_RGr=G_dâ¢d_G-G_sâ¢s_GBr=B_dâ¢d_B-B_sâ¢s_B, Ar=A_dâ¢d_A-A_sâ¢s_A
GL_MIN: Rr=minâ¡(R_s,R_d)Gr=minâ¡(G_s,G_d)Br=minâ¡(B_s,B_d), Ar=minâ¡(A_s,A_d)
GL_MAX: Rr=maxâ¡(R_s,R_d)Gr=maxâ¡(G_s,G_d)Br=maxâ¡(B_s,B_d), Ar=maxâ¡(A_s,A_d)

The results of these equations are clamped to the range [0,1].

Initially, both the RGB blend equation and the alpha blend equation are set to GL_FUNC_ADD.

GL_INVALID_ENUM is generated if mode is not one of GL_FUNC_ADD, GL_FUNC_SUBTRACT, GL_FUNC_REVERSE_SUBTRACT, GL_MAX, or GL_MIN.

GL_INVALID_OPERATION is generated if glBlendEquation is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBlendFuncSeparate srcRGB dstRGB srcAlpha dstAlpha

Specify pixel arithmetic for RGB and alpha components separately.

srcRGB: Specifies how the red, green, and blue blending factors are computed. The following symbolic constants are accepted: GL_ZERO, GL_ONE, GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR, GL_DST_COLOR, GL_ONE_MINUS_DST_COLOR, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_DST_ALPHA, GL_ONE_MINUS_DST_ALPHA, GL_CONSTANT_COLOR, GL_ONE_MINUS_CONSTANT_COLOR, GL_CONSTANT_ALPHA, GL_ONE_MINUS_CONSTANT_ALPHA, and GL_SRC_ALPHA_SATURATE. The initial value is GL_ONE.
dstRGB: Specifies how the red, green, and blue destination blending factors are computed. The following symbolic constants are accepted: GL_ZERO, GL_ONE, GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR, GL_DST_COLOR, GL_ONE_MINUS_DST_COLOR, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_DST_ALPHA, GL_ONE_MINUS_DST_ALPHA. GL_CONSTANT_COLOR, GL_ONE_MINUS_CONSTANT_COLOR, GL_CONSTANT_ALPHA, and GL_ONE_MINUS_CONSTANT_ALPHA. The initial value is GL_ZERO.
srcAlpha: Specified how the alpha source blending factor is computed. The same symbolic constants are accepted as for srcRGB. The initial value is GL_ONE.
dstAlpha: Specified how the alpha destination blending factor is computed. The same symbolic constants are accepted as for dstRGB. The initial value is GL_ZERO.

In RGBA mode, pixels can be drawn using a function that blends the incoming (source) RGBA values with the RGBA values that are already in the frame buffer (the destination values). Blending is initially disabled. Use glEnable and glDisable with argument GL_BLEND to enable and disable blending.

glBlendFuncSeparate defines the operation of blending when it is enabled. srcRGB specifies which method is used to scale the source RGB-color components. dstRGB specifies which method is used to scale the destination RGB-color components. Likewise, srcAlpha specifies which method is used to scale the source alpha color component, and dstAlpha specifies which method is used to scale the destination alpha component. The possible methods are described in the following table. Each method defines four scale factors, one each for red, green, blue, and alpha.

In the table and in subsequent equations, source and destination color components are referred to as (R_s,G_sB_sA_s) and (R_d,G_dB_dA_d). The color specified by glBlendColor is referred to as (R_c,G_cB_cA_c). They are understood to have integer values between 0 and (k_R,k_Gk_Bk_A), where

k_c=2^m_c,-1

and (m_R,m_Gm_Bm_A) is the number of red, green, blue, and alpha bitplanes.

Source and destination scale factors are referred to as (s_R,s_Gs_Bs_A) and (d_R,d_Gd_Bd_A). All scale factors have range [0,1].

Parameter: RGB Factor, Alpha Factor
GL_ZERO: (0,00), 0
GL_ONE: (1,11), 1
GL_SRC_COLOR: (R_s/k_R,G_s/k_GB_s/k_B), A_s/k_A
GL_ONE_MINUS_SRC_COLOR: (1,111)-(R_s/k_R,G_s/k_GB_s/k_B), 1-A_s/k_A
GL_DST_COLOR: (R_d/k_R,G_d/k_GB_d/k_B), A_d/k_A
GL_ONE_MINUS_DST_COLOR: (1,11)-(R_d/k_R,G_d/k_GB_d/k_B), 1-A_d/k_A
GL_SRC_ALPHA: (A_s/k_A,A_s/k_AA_s/k_A), A_s/k_A
GL_ONE_MINUS_SRC_ALPHA: (1,11)-(A_s/k_A,A_s/k_AA_s/k_A), 1-A_s/k_A
GL_DST_ALPHA: (A_d/k_A,A_d/k_AA_d/k_A), A_d/k_A
GL_ONE_MINUS_DST_ALPHA: (1,11)-(A_d/k_A,A_d/k_AA_d/k_A), 1-A_d/k_A
GL_CONSTANT_COLOR: (R_c,G_cB_c), A_c
GL_ONE_MINUS_CONSTANT_COLOR: (1,11)-(R_c,G_cB_c), 1-A_c
GL_CONSTANT_ALPHA: (A_c,A_cA_c), A_c
GL_ONE_MINUS_CONSTANT_ALPHA: (1,11)-(A_c,A_cA_c), 1-A_c
GL_SRC_ALPHA_SATURATE: (i,ii), 1

In the table,

i=minâ¡(A_s,1-A_d,)

To determine the blended RGBA values of a pixel when drawing in RGBA mode, the system uses the following equations:

R_d=minâ¡(k_R,R_sâ¢s_R+R_dâ¢d_R)G_d=minâ¡(k_G,G_sâ¢s_G+G_dâ¢d_G)B_d=minâ¡(k_B,B_sâ¢s_B+B_dâ¢d_B)A_d=minâ¡(k_A,A_sâ¢s_A+A_dâ¢d_A)

Despite the apparent precision of the above equations, blending arithmetic is not exactly specified, because blending operates with imprecise integer color values. However, a blend factor that should be equal to 1 is guaranteed not to modify its multiplicand, and a blend factor equal to 0 reduces its multiplicand to 0. For example, when srcRGB is GL_SRC_ALPHA, dstRGB is GL_ONE_MINUS_SRC_ALPHA, and A_s is equal to k_A, the equations reduce to simple replacement:

R_d=R_sG_d=G_sB_d=B_sA_d=A_s

GL_INVALID_ENUM is generated if either srcRGB or dstRGB is not an accepted value.

GL_INVALID_OPERATION is generated if glBlendFuncSeparate is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBlendFunc sfactor dfactor

Specify pixel arithmetic.

sfactor: Specifies how the red, green, blue, and alpha source blending factors are computed. The following symbolic constants are accepted: GL_ZERO, GL_ONE, GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR, GL_DST_COLOR, GL_ONE_MINUS_DST_COLOR, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_DST_ALPHA, GL_ONE_MINUS_DST_ALPHA, GL_CONSTANT_COLOR, GL_ONE_MINUS_CONSTANT_COLOR, GL_CONSTANT_ALPHA, GL_ONE_MINUS_CONSTANT_ALPHA, and GL_SRC_ALPHA_SATURATE. The initial value is GL_ONE.
dfactor: Specifies how the red, green, blue, and alpha destination blending factors are computed. The following symbolic constants are accepted: GL_ZERO, GL_ONE, GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR, GL_DST_COLOR, GL_ONE_MINUS_DST_COLOR, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_DST_ALPHA, GL_ONE_MINUS_DST_ALPHA. GL_CONSTANT_COLOR, GL_ONE_MINUS_CONSTANT_COLOR, GL_CONSTANT_ALPHA, and GL_ONE_MINUS_CONSTANT_ALPHA. The initial value is GL_ZERO.

glBlendFunc defines the operation of blending when it is enabled. sfactor specifies which method is used to scale the source color components. dfactor specifies which method is used to scale the destination color components. The possible methods are described in the following table. Each method defines four scale factors, one each for red, green, blue, and alpha. In the table and in subsequent equations, source and destination color components are referred to as (R_s,G_sB_sA_s) and (R_d,G_dB_dA_d). The color specified by glBlendColor is referred to as (R_c,G_cB_cA_c). They are understood to have integer values between 0 and (k_R,k_Gk_Bk_A), where

k_c=2^m_c,-1

and (m_R,m_Gm_Bm_A) is the number of red, green, blue, and alpha bitplanes.

Source and destination scale factors are referred to as (s_R,s_Gs_Bs_A) and (d_R,d_Gd_Bd_A). The scale factors described in the table, denoted (f_R,f_Gf_Bf_A), represent either source or destination factors. All scale factors have range [0,1].

Parameter: (f_R,f_Gf_Bf_A)
GL_ZERO: (0,000)
GL_ONE: (1,111)
GL_SRC_COLOR: (R_s/k_R,G_s/k_GB_s/k_BA_s/k_A)
GL_ONE_MINUS_SRC_COLOR: (1,111)-(R_s/k_R,G_s/k_GB_s/k_BA_s/k_A)
GL_DST_COLOR: (R_d/k_R,G_d/k_GB_d/k_BA_d/k_A)
GL_ONE_MINUS_DST_COLOR: (1,111)-(R_d/k_R,G_d/k_GB_d/k_BA_d/k_A)
GL_SRC_ALPHA: (A_s/k_A,A_s/k_AA_s/k_AA_s/k_A)
GL_ONE_MINUS_SRC_ALPHA: (1,111)-(A_s/k_A,A_s/k_AA_s/k_AA_s/k_A)
GL_DST_ALPHA: (A_d/k_A,A_d/k_AA_d/k_AA_d/k_A)
GL_ONE_MINUS_DST_ALPHA: (1,111)-(A_d/k_A,A_d/k_AA_d/k_AA_d/k_A)
GL_CONSTANT_COLOR: (R_c,G_cB_cA_c)
GL_ONE_MINUS_CONSTANT_COLOR: (1,111)-(R_c,G_cB_cA_c)
GL_CONSTANT_ALPHA: (A_c,A_cA_cA_c)
GL_ONE_MINUS_CONSTANT_ALPHA: (1,111)-(A_c,A_cA_cA_c)
GL_SRC_ALPHA_SATURATE: (i,ii1)

In the table,

i=minâ¡(A_s,k_A-A_d)/k_A

To determine the blended RGBA values of a pixel when drawing in RGBA mode, the system uses the following equations:

Despite the apparent precision of the above equations, blending arithmetic is not exactly specified, because blending operates with imprecise integer color values. However, a blend factor that should be equal to 1 is guaranteed not to modify its multiplicand, and a blend factor equal to 0 reduces its multiplicand to 0. For example, when sfactor is GL_SRC_ALPHA, dfactor is GL_ONE_MINUS_SRC_ALPHA, and A_s is equal to k_A, the equations reduce to simple replacement:

R_d=R_sG_d=G_sB_d=B_sA_d=A_s

GL_INVALID_ENUM is generated if either sfactor or dfactor is not an accepted value.

GL_INVALID_OPERATION is generated if glBlendFunc is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBufferData target size data usage

Creates and initializes a buffer object’s data store.

target: Specifies the target buffer object. The symbolic constant must be GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.
size: Specifies the size in bytes of the buffer object’s new data store.
data: Specifies a pointer to data that will be copied into the data store for initialization, or NULL if no data is to be copied.
usage: Specifies the expected usage pattern of the data store. The symbolic constant must be GL_STREAM_DRAW, GL_STREAM_READ, GL_STREAM_COPY, GL_STATIC_DRAW, GL_STATIC_READ, GL_STATIC_COPY, GL_DYNAMIC_DRAW, GL_DYNAMIC_READ, or GL_DYNAMIC_COPY.

glBufferData creates a new data store for the buffer object currently bound to target. Any pre-existing data store is deleted. The new data store is created with the specified size in bytes and usage. If data is not NULL, the data store is initialized with data from this pointer. In its initial state, the new data store is not mapped, it has a NULL mapped pointer, and its mapped access is GL_READ_WRITE.

usage is a hint to the GL implementation as to how a buffer object’s data store will be accessed. This enables the GL implementation to make more intelligent decisions that may significantly impact buffer object performance. It does not, however, constrain the actual usage of the data store. usage can be broken down into two parts: first, the frequency of access (modification and usage), and second, the nature of that access. The frequency of access may be one of these:

STREAM: The data store contents will be modified once and used at most a few times.
STATIC: The data store contents will be modified once and used many times.
DYNAMIC: The data store contents will be modified repeatedly and used many times.

The nature of access may be one of these:

DRAW: The data store contents are modified by the application, and used as the source for GL drawing and image specification commands.
READ: The data store contents are modified by reading data from the GL, and used to return that data when queried by the application.
COPY: The data store contents are modified by reading data from the GL, and used as the source for GL drawing and image specification commands.

GL_INVALID_ENUM is generated if target is not GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.

GL_INVALID_ENUM is generated if usage is not GL_STREAM_DRAW, GL_STREAM_READ, GL_STREAM_COPY, GL_STATIC_DRAW, GL_STATIC_READ, GL_STATIC_COPY, GL_DYNAMIC_DRAW, GL_DYNAMIC_READ, or GL_DYNAMIC_COPY.

GL_INVALID_VALUE is generated if size is negative.

GL_INVALID_OPERATION is generated if the reserved buffer object name 0 is bound to target.

GL_OUT_OF_MEMORY is generated if the GL is unable to create a data store with the specified size.

GL_INVALID_OPERATION is generated if glBufferData is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glBufferSubData target offset size data

Updates a subset of a buffer object’s data store.

target: Specifies the target buffer object. The symbolic constant must be GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.
offset: Specifies the offset into the buffer object’s data store where data replacement will begin, measured in bytes.
size: Specifies the size in bytes of the data store region being replaced.
data: Specifies a pointer to the new data that will be copied into the data store.

glBufferSubData redefines some or all of the data store for the buffer object currently bound to target. Data starting at byte offset offset and extending for size bytes is copied to the data store from the memory pointed to by data. An error is thrown if offset and size together define a range beyond the bounds of the buffer object’s data store.

GL_INVALID_ENUM is generated if target is not GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.

GL_INVALID_VALUE is generated if offset or size is negative, or if together they define a region of memory that extends beyond the buffer object’s allocated data store.

GL_INVALID_OPERATION is generated if the reserved buffer object name 0 is bound to target.

GL_INVALID_OPERATION is generated if the buffer object being updated is mapped.

GL_INVALID_OPERATION is generated if glBufferSubData is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCallLists n type lists

Execute a list of display lists.

n: Specifies the number of display lists to be executed.
type: Specifies the type of values in lists. Symbolic constants GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT, GL_FLOAT, GL_2_BYTES, GL_3_BYTES, and GL_4_BYTES are accepted.
lists: Specifies the address of an array of name offsets in the display list. The pointer type is void because the offsets can be bytes, shorts, ints, or floats, depending on the value of type.

glCallLists causes each display list in the list of names passed as lists to be executed. As a result, the commands saved in each display list are executed in order, just as if they were called without using a display list. Names of display lists that have not been defined are ignored.

glCallLists provides an efficient means for executing more than one display list. type allows lists with various name formats to be accepted. The formats are as follows:

GL_BYTE: lists is treated as an array of signed bytes, each in the range -128 through 127.
GL_UNSIGNED_BYTE: lists is treated as an array of unsigned bytes, each in the range 0 through 255.
GL_SHORT: lists is treated as an array of signed two-byte integers, each in the range -32768 through 32767.
GL_UNSIGNED_SHORT: lists is treated as an array of unsigned two-byte integers, each in the range 0 through 65535.
GL_INT: lists is treated as an array of signed four-byte integers.
GL_UNSIGNED_INT: lists is treated as an array of unsigned four-byte integers.
GL_FLOAT: lists is treated as an array of four-byte floating-point values.
GL_2_BYTES: lists is treated as an array of unsigned bytes. Each pair of bytes specifies a single display-list name. The value of the pair is computed as 256 times the unsigned value of the first byte plus the unsigned value of the second byte.
GL_3_BYTES: lists is treated as an array of unsigned bytes. Each triplet of bytes specifies a single display-list name. The value of the triplet is computed as 65536 times the unsigned value of the first byte, plus 256 times the unsigned value of the second byte, plus the unsigned value of the third byte.
GL_4_BYTES: lists is treated as an array of unsigned bytes. Each quadruplet of bytes specifies a single display-list name. The value of the quadruplet is computed as 16777216 times the unsigned value of the first byte, plus 65536 times the unsigned value of the second byte, plus 256 times the unsigned value of the third byte, plus the unsigned value of the fourth byte.

The list of display-list names is not null-terminated. Rather, n specifies how many names are to be taken from lists.

An additional level of indirection is made available with the glListBase command, which specifies an unsigned offset that is added to each display-list name specified in lists before that display list is executed.

glCallLists can appear inside a display list. To avoid the possibility of infinite recursion resulting from display lists calling one another, a limit is placed on the nesting level of display lists during display-list execution. This limit must be at least 64, and it depends on the implementation.

GL state is not saved and restored across a call to glCallLists. Thus, changes made to GL state during the execution of the display lists remain after execution is completed. Use glPushAttrib, glPopAttrib, glPushMatrix, and glPopMatrix to preserve GL state across glCallLists calls.

GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_ENUM is generated if type is not one of GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT, GL_FLOAT, GL_2_BYTES, GL_3_BYTES, GL_4_BYTES.

Function: void glCallList list

Execute a display list.

list: Specifies the integer name of the display list to be executed.

glCallList causes the named display list to be executed. The commands saved in the display list are executed in order, just as if they were called without using a display list. If list has not been defined as a display list, glCallList is ignored.

glCallList can appear inside a display list. To avoid the possibility of infinite recursion resulting from display lists calling one another, a limit is placed on the nesting level of display lists during display-list execution. This limit is at least 64, and it depends on the implementation.

GL state is not saved and restored across a call to glCallList. Thus, changes made to GL state during the execution of a display list remain after execution of the display list is completed. Use glPushAttrib, glPopAttrib, glPushMatrix, and glPopMatrix to preserve GL state across glCallList calls.

Function: void glClearAccum red green blue alpha

Specify clear values for the accumulation buffer.

red
green
blue
alpha: Specify the red, green, blue, and alpha values used when the accumulation buffer is cleared. The initial values are all 0.

glClearAccum specifies the red, green, blue, and alpha values used by glClear to clear the accumulation buffer.

Values specified by glClearAccum are clamped to the range [-1,1].

GL_INVALID_OPERATION is generated if glClearAccum is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glClearColor red green blue alpha

Specify clear values for the color buffers.

red
green
blue
alpha: Specify the red, green, blue, and alpha values used when the color buffers are cleared. The initial values are all 0.

glClearColor specifies the red, green, blue, and alpha values used by glClear to clear the color buffers. Values specified by glClearColor are clamped to the range [0,1].

GL_INVALID_OPERATION is generated if glClearColor is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glClearDepth depth

Specify the clear value for the depth buffer.

depth: Specifies the depth value used when the depth buffer is cleared. The initial value is 1.

glClearDepth specifies the depth value used by glClear to clear the depth buffer. Values specified by glClearDepth are clamped to the range [0,1].

GL_INVALID_OPERATION is generated if glClearDepth is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glClearIndex c

Specify the clear value for the color index buffers.

c: Specifies the index used when the color index buffers are cleared. The initial value is 0.

glClearIndex specifies the index used by glClear to clear the color index buffers. c is not clamped. Rather, c is converted to a fixed-point value with unspecified precision to the right of the binary point. The integer part of this value is then masked with 2^m-1, where m is the number of bits in a color index stored in the frame buffer.

GL_INVALID_OPERATION is generated if glClearIndex is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glClearStencil s

Specify the clear value for the stencil buffer.

s: Specifies the index used when the stencil buffer is cleared. The initial value is 0.

glClearStencil specifies the index used by glClear to clear the stencil buffer. s is masked with 2^m-1, where m is the number of bits in the stencil buffer.

GL_INVALID_OPERATION is generated if glClearStencil is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glClear mask

Clear buffers to preset values.

mask: Bitwise OR of masks that indicate the buffers to be cleared. The four masks are GL_COLOR_BUFFER_BIT, GL_DEPTH_BUFFER_BIT, GL_ACCUM_BUFFER_BIT, and GL_STENCIL_BUFFER_BIT.

glClear sets the bitplane area of the window to values previously selected by glClearColor, glClearIndex, glClearDepth, glClearStencil, and glClearAccum. Multiple color buffers can be cleared simultaneously by selecting more than one buffer at a time using glDrawBuffer.

The pixel ownership test, the scissor test, dithering, and the buffer writemasks affect the operation of glClear. The scissor box bounds the cleared region. Alpha function, blend function, logical operation, stenciling, texture mapping, and depth-buffering are ignored by glClear.

glClear takes a single argument that is the bitwise OR of several values indicating which buffer is to be cleared.

The values are as follows:

GL_COLOR_BUFFER_BIT: Indicates the buffers currently enabled for color writing.
GL_DEPTH_BUFFER_BIT: Indicates the depth buffer.
GL_ACCUM_BUFFER_BIT: Indicates the accumulation buffer.
GL_STENCIL_BUFFER_BIT: Indicates the stencil buffer.

The value to which each buffer is cleared depends on the setting of the clear value for that buffer.

GL_INVALID_VALUE is generated if any bit other than the four defined bits is set in mask.

GL_INVALID_OPERATION is generated if glClear is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glClientActiveTexture texture

Select active texture unit.

texture: Specifies which texture unit to make active. The number of texture units is implementation dependent, but must be at least two. texture must be one of GL_TEXTUREi, where i ranges from 0 to the value of GL_MAX_TEXTURE_COORDS - 1, which is an implementation-dependent value. The initial value is GL_TEXTURE0.

glClientActiveTexture selects the vertex array client state parameters to be modified by glTexCoordPointer, and enabled or disabled with glEnableClientState or glDisableClientState, respectively, when called with a parameter of GL_TEXTURE_COORD_ARRAY.

GL_INVALID_ENUM is generated if texture is not one of GL_TEXTUREi, where i ranges from 0 to the value of GL_MAX_TEXTURE_COORDS - 1.

Function: void glClipPlane plane equation

Specify a plane against which all geometry is clipped.

plane: Specifies which clipping plane is being positioned. Symbolic names of the form GL_CLIP_PLANEi, where i is an integer between 0 and GL_MAX_CLIP_PLANES-1, are accepted.
equation: Specifies the address of an array of four double-precision floating-point values. These values are interpreted as a plane equation.

Geometry is always clipped against the boundaries of a six-plane frustum in x, y, and z. glClipPlane allows the specification of additional planes, not necessarily perpendicular to the x, y, or z axis, against which all geometry is clipped. To determine the maximum number of additional clipping planes, call glGetIntegerv with argument GL_MAX_CLIP_PLANES. All implementations support at least six such clipping planes. Because the resulting clipping region is the intersection of the defined half-spaces, it is always convex.

glClipPlane specifies a half-space using a four-component plane equation. When glClipPlane is called, equation is transformed by the inverse of the modelview matrix and stored in the resulting eye coordinates. Subsequent changes to the modelview matrix have no effect on the stored plane-equation components. If the dot product of the eye coordinates of a vertex with the stored plane equation components is positive or zero, the vertex is in with respect to that clipping plane. Otherwise, it is out.

To enable and disable clipping planes, call glEnable and glDisable with the argument GL_CLIP_PLANEi, where i is the plane number.

All clipping planes are initially defined as (0, 0, 0, 0) in eye coordinates and are disabled.

GL_INVALID_ENUM is generated if plane is not an accepted value.

GL_INVALID_OPERATION is generated if glClipPlane is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glColorMask red green blue alpha

Enable and disable writing of frame buffer color components.

red
green
blue
alpha: Specify whether red, green, blue, and alpha can or cannot be written into the frame buffer. The initial values are all GL_TRUE, indicating that the color components can be written.

glColorMask specifies whether the individual color components in the frame buffer can or cannot be written. If red is GL_FALSE, for example, no change is made to the red component of any pixel in any of the color buffers, regardless of the drawing operation attempted.

Changes to individual bits of components cannot be controlled. Rather, changes are either enabled or disabled for entire color components.

GL_INVALID_OPERATION is generated if glColorMask is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glColorMaterial face mode

Cause a material color to track the current color.

face: Specifies whether front, back, or both front and back material parameters should track the current color. Accepted values are GL_FRONT, GL_BACK, and GL_FRONT_AND_BACK. The initial value is GL_FRONT_AND_BACK.
mode: Specifies which of several material parameters track the current color. Accepted values are GL_EMISSION, GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, and GL_AMBIENT_AND_DIFFUSE. The initial value is GL_AMBIENT_AND_DIFFUSE.

glColorMaterial specifies which material parameters track the current color. When GL_COLOR_MATERIAL is enabled, the material parameter or parameters specified by mode, of the material or materials specified by face, track the current color at all times.

To enable and disable GL_COLOR_MATERIAL, call glEnable and glDisable with argument GL_COLOR_MATERIAL. GL_COLOR_MATERIAL is initially disabled.

GL_INVALID_ENUM is generated if face or mode is not an accepted value.

GL_INVALID_OPERATION is generated if glColorMaterial is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glColorPointer size type stride pointer

Define an array of colors.

size: Specifies the number of components per color. Must be 3 or 4. The initial value is 4.
type: Specifies the data type of each color component in the array. Symbolic constants GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT, GL_FLOAT, and GL_DOUBLE are accepted. The initial value is GL_FLOAT.
stride: Specifies the byte offset between consecutive colors. If stride is 0, the colors are understood to be tightly packed in the array. The initial value is 0.
pointer: Specifies a pointer to the first component of the first color element in the array. The initial value is 0.

glColorPointer specifies the location and data format of an array of color components to use when rendering. size specifies the number of components per color, and must be 3 or 4. type specifies the data type of each color component, and stride specifies the byte stride from one color to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on some implementations; see glInterleavedArrays.)

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer) while a color array is specified, pointer is treated as a byte offset into the buffer object’s data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as color vertex array client-side state (GL_COLOR_ARRAY_BUFFER_BINDING).

When a color array is specified, size, type, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable the color array, call glEnableClientState and glDisableClientState with the argument GL_COLOR_ARRAY. If enabled, the color array is used when glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, glDrawRangeElements, or glArrayElement is called.

GL_INVALID_VALUE is generated if size is not 3 or 4.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if stride is negative.

Function: void glColorSubTable target start count format type data

Respecify a portion of a color table.

target: Must be one of GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, or GL_POST_COLOR_MATRIX_COLOR_TABLE.
start: The starting index of the portion of the color table to be replaced.
count: The number of table entries to replace.
format: The format of the pixel data in data. The allowable values are GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, GL_BGR, GL_RGBA, and GL_BGRA.
type: The type of the pixel data in data. The allowable values are GL_UNSIGNED_BYTE, GL_BYTE, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
data: Pointer to a one-dimensional array of pixel data that is processed to replace the specified region of the color table.

glColorSubTable is used to respecify a contiguous portion of a color table previously defined using glColorTable. The pixels referenced by data replace the portion of the existing table from indices start to start+count-1, inclusive. This region may not include any entries outside the range of the color table as it was originally specified. It is not an error to specify a subtexture with width of 0, but such a specification has no effect.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a portion of a color table is respecified, data is treated as a byte offset into the buffer object’s data store.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if type is not one of the allowable values.

GL_INVALID_VALUE is generated if start+count>width.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and data is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

GL_INVALID_OPERATION is generated if glColorSubTable is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glColorTableParameterfv target pname params

Function: void glColorTableParameteriv target pname params

Set color lookup table parameters.

target: The target color table. Must be GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, or GL_POST_COLOR_MATRIX_COLOR_TABLE.
pname: The symbolic name of a texture color lookup table parameter. Must be one of GL_COLOR_TABLE_SCALE or GL_COLOR_TABLE_BIAS.
params: A pointer to an array where the values of the parameters are stored.

glColorTableParameter is used to specify the scale factors and bias terms applied to color components when they are loaded into a color table. target indicates which color table the scale and bias terms apply to; it must be set to GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, or GL_POST_COLOR_MATRIX_COLOR_TABLE.

pname must be GL_COLOR_TABLE_SCALE to set the scale factors. In this case, params points to an array of four values, which are the scale factors for red, green, blue, and alpha, in that order.

pname must be GL_COLOR_TABLE_BIAS to set the bias terms. In this case, params points to an array of four values, which are the bias terms for red, green, blue, and alpha, in that order.

The color tables themselves are specified by calling glColorTable.

GL_INVALID_ENUM is generated if target or pname is not an acceptable value.

GL_INVALID_OPERATION is generated if glColorTableParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glColorTable target internalformat width format type data

Define a color lookup table.

target: Must be one of GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, GL_POST_COLOR_MATRIX_COLOR_TABLE, GL_PROXY_COLOR_TABLE, GL_PROXY_POST_CONVOLUTION_COLOR_TABLE, or GL_PROXY_POST_COLOR_MATRIX_COLOR_TABLE.
internalformat: The internal format of the color table. The allowable values are GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, and GL_RGBA16.
width: The number of entries in the color lookup table specified by data.
format: The format of the pixel data in data. The allowable values are GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, GL_BGR, GL_RGBA, and GL_BGRA.
type: The type of the pixel data in data. The allowable values are GL_UNSIGNED_BYTE, GL_BYTE, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
data: Pointer to a one-dimensional array of pixel data that is processed to build the color table.

glColorTable may be used in two ways: to test the actual size and color resolution of a lookup table given a particular set of parameters, or to load the contents of a color lookup table. Use the targets GL_PROXY_* for the first case and the other targets for the second case.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a color table is specified, data is treated as a byte offset into the buffer object’s data store.

If target is GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, or GL_POST_COLOR_MATRIX_COLOR_TABLE, glColorTable builds a color lookup table from an array of pixels. The pixel array specified by width, format, type, and data is extracted from memory and processed just as if glDrawPixels were called, but processing stops after the final expansion to RGBA is completed.

The four scale parameters and the four bias parameters that are defined for the table are then used to scale and bias the R, G, B, and A components of each pixel. (Use glColorTableParameter to set these scale and bias parameters.)

Next, the R, G, B, and A values are clamped to the range [0,1]. Each pixel is then converted to the internal format specified by internalformat. This conversion simply maps the component values of the pixel (R, G, B, and A) to the values included in the internal format (red, green, blue, alpha, luminance, and intensity). The mapping is as follows:

Internal Format: Red, Green, Blue, Alpha, Luminance, Intensity
GL_ALPHA: , , , A , ,
GL_LUMINANCE: , , , , R ,
GL_LUMINANCE_ALPHA: , , , A , R ,
GL_INTENSITY: , , , , , R
GL_RGB: R , G , B , , ,
GL_RGBA: R , G , B , A , ,

Finally, the red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are stored in the color table. They form a one-dimensional table with indices in the range [0,width-1].

If target is GL_PROXY_*, glColorTable recomputes and stores the values of the proxy color table’s state variables GL_COLOR_TABLE_FORMAT, GL_COLOR_TABLE_WIDTH, GL_COLOR_TABLE_RED_SIZE, GL_COLOR_TABLE_GREEN_SIZE, GL_COLOR_TABLE_BLUE_SIZE, GL_COLOR_TABLE_ALPHA_SIZE, GL_COLOR_TABLE_LUMINANCE_SIZE, and GL_COLOR_TABLE_INTENSITY_SIZE. There is no effect on the image or state of any actual color table. If the specified color table is too large to be supported, then all the proxy state variables listed above are set to zero. Otherwise, the color table could be supported by glColorTable using the corresponding non-proxy target, and the proxy state variables are set as if that target were being defined.

The proxy state variables can be retrieved by calling glGetColorTableParameter with a target of GL_PROXY_*. This allows the application to decide if a particular glColorTable command would succeed, and to determine what the resulting color table attributes would be.

If a color table is enabled, and its width is non-zero, then its contents are used to replace a subset of the components of each RGBA pixel group, based on the internal format of the table.

Each pixel group has color components (R, G, B, A) that are in the range [0.0,1.0]. The color components are rescaled to the size of the color lookup table to form an index. Then a subset of the components based on the internal format of the table are replaced by the table entry selected by that index. If the color components and contents of the table are represented as follows:

Representation: Meaning
r: Table index computed from R
g: Table index computed from G
b: Table index computed from B
a: Table index computed from A
L[i]: Luminance value at table index i
I[i]: Intensity value at table index i
R[i]: Red value at table index i
G[i]: Green value at table index i
B[i]: Blue value at table index i
A[i]: Alpha value at table index i

then the result of color table lookup is as follows:

: Resulting Texture Components
Table Internal Format: R, G, B, A
GL_ALPHA: R, G, B, A[a]
GL_LUMINANCE: L[r], L[g], L[b], At
GL_LUMINANCE_ALPHA: L[r], L[g], L[b], A[a]
GL_INTENSITY: I[r], I[g], I[b], I[a]
GL_RGB: R[r], G[g], B[b], A
GL_RGBA: R[r], G[g], B[b], A[a]

When GL_COLOR_TABLE is enabled, the colors resulting from the pixel map operation (if it is enabled) are mapped by the color lookup table before being passed to the convolution operation. The colors resulting from the convolution operation are modified by the post convolution color lookup table when GL_POST_CONVOLUTION_COLOR_TABLE is enabled. These modified colors are then sent to the color matrix operation. Finally, if GL_POST_COLOR_MATRIX_COLOR_TABLE is enabled, the colors resulting from the color matrix operation are mapped by the post color matrix color lookup table before being used by the histogram operation.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if internalformat is not one of the allowable values.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if type is not one of the allowable values.

GL_INVALID_VALUE is generated if width is less than zero.

GL_TABLE_TOO_LARGE is generated if the requested color table is too large to be supported by the implementation, and target is not a GL_PROXY_* target.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glColorTable is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glColor3b red green blue

Function: void glColor3s red green blue

Function: void glColor3i red green blue

Function: void glColor3f red green blue

Function: void glColor3d red green blue

Function: void glColor3ub red green blue

Function: void glColor3us red green blue

Function: void glColor3ui red green blue

Function: void glColor4b red green blue alpha

Function: void glColor4s red green blue alpha

Function: void glColor4i red green blue alpha

Function: void glColor4f red green blue alpha

Function: void glColor4d red green blue alpha

Function: void glColor4ub red green blue alpha

Function: void glColor4us red green blue alpha

Function: void glColor4ui red green blue alpha

Function: void glColor3bv v

Function: void glColor3sv v

Function: void glColor3iv v

Function: void glColor3fv v

Function: void glColor3dv v

Function: void glColor3ubv v

Function: void glColor3usv v

Function: void glColor3uiv v

Function: void glColor4bv v

Function: void glColor4sv v

Function: void glColor4iv v

Function: void glColor4fv v

Function: void glColor4dv v

Function: void glColor4ubv v

Function: void glColor4usv v

Function: void glColor4uiv v

Set the current color.

red
green
blue: Specify new red, green, and blue values for the current color.
alpha: Specifies a new alpha value for the current color. Included only in the four-argument glColor4 commands.

The GL stores both a current single-valued color index and a current four-valued RGBA color. glColor sets a new four-valued RGBA color. glColor has two major variants: glColor3 and glColor4. glColor3 variants specify new red, green, and blue values explicitly and set the current alpha value to 1.0 (full intensity) implicitly. glColor4 variants specify all four color components explicitly.

glColor3b, glColor4b, glColor3s, glColor4s, glColor3i, and glColor4i take three or four signed byte, short, or long integers as arguments. When v is appended to the name, the color commands can take a pointer to an array of such values.

Current color values are stored in floating-point format, with unspecified mantissa and exponent sizes. Unsigned integer color components, when specified, are linearly mapped to floating-point values such that the largest representable value maps to 1.0 (full intensity), and 0 maps to 0.0 (zero intensity). Signed integer color components, when specified, are linearly mapped to floating-point values such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. (Note that this mapping does not convert 0 precisely to 0.0.) Floating-point values are mapped directly.

Neither floating-point nor signed integer values are clamped to the range [0,1] before the current color is updated. However, color components are clamped to this range before they are interpolated or written into a color buffer.

Function: void glCompileShader shader

Compiles a shader object.

shader: Specifies the shader object to be compiled.

glCompileShader compiles the source code strings that have been stored in the shader object specified by shader.

The compilation status will be stored as part of the shader object’s state. This value will be set to GL_TRUE if the shader was compiled without errors and is ready for use, and GL_FALSE otherwise. It can be queried by calling glGetShader with arguments shader and GL_COMPILE_STATUS.

Compilation of a shader can fail for a number of reasons as specified by the OpenGL Shading Language Specification. Whether or not the compilation was successful, information about the compilation can be obtained from the shader object’s information log by calling glGetShaderInfoLog.

GL_INVALID_VALUE is generated if shader is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if shader is not a shader object.

GL_INVALID_OPERATION is generated if glCompileShader is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCompressedTexImage1D target level internalformat width border imageSize data

Specify a one-dimensional texture image in a compressed format.

target: Specifies the target texture. Must be GL_TEXTURE_1D or GL_PROXY_TEXTURE_1D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
internalformat: Specifies the format of the compressed image data stored at address data.
width: Specifies the width of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^n+2â¡(border,) for some integer n. All implementations support texture images that are at least 64 texels wide. The height of the 1D texture image is 1.
border: Specifies the width of the border. Must be either 0 or 1.
imageSize: Specifies the number of unsigned bytes of image data starting at the address specified by data.
data: Specifies a pointer to the compressed image data in memory.

Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable one-dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_1D.

glCompressedTexImage1D loads a previously defined, and retrieved, compressed one-dimensional texture image if target is GL_TEXTURE_1D (see glTexImage1D).

If target is GL_PROXY_TEXTURE_1D, no data is read from data, but all of the texture image state is recalculated, checked for consistency, and checked against the implementation’s capabilities. If the implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but does not generate an error (see glGetError). To query for an entire mipmap array, use an image array level greater than or equal to 1.

internalformat must be extension-specified compressed-texture format. When a texture is loaded with glTexImage1D using a generic compressed texture format (e.g., GL_COMPRESSED_RGB) the GL selects from one of its extensions supporting compressed textures. In order to load the compressed texture image using glCompressedTexImage1D, query the compressed texture image’s size and format using glGetTexLevelParameter.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a texture image is specified, data is treated as a byte offset into the buffer object’s data store.

GL_INVALID_ENUM is generated if internalformat is one of the generic compressed internal formats: GL_COMPRESSED_ALPHA, GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_INTENSITY, GL_COMPRESSED_RGB, or GL_COMPRESSED_RGBA.

GL_INVALID_VALUE is generated if imageSize is not consistent with the format, dimensions, and contents of the specified compressed image data.

GL_INVALID_OPERATION is generated if parameter combinations are not supported by the specific compressed internal format as specified in the specific texture compression extension.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glCompressedTexImage1D is executed between the execution of glBegin and the corresponding execution of glEnd.

Undefined results, including abnormal program termination, are generated if data is not encoded in a manner consistent with the extension specification defining the internal compression format.

Function: void glCompressedTexImage2D target level internalformat width height border imageSize data

Specify a two-dimensional texture image in a compressed format.

target: Specifies the target texture. Must be GL_TEXTURE_2D, GL_PROXY_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, or GL_PROXY_TEXTURE_CUBE_MAP.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
internalformat: Specifies the format of the compressed image data stored at address data.
width: Specifies the width of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^n+2â¡(border,) for some integer n. All implementations support 2D texture images that are at least 64 texels wide and cube-mapped texture images that are at least 16 texels wide.
height: Specifies the height of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be Must be 2^n+2â¡(border,) for some integer n. All implementations support 2D texture images that are at least 64 texels high and cube-mapped texture images that are at least 16 texels high.
border: Specifies the width of the border. Must be either 0 or 1.
imageSize: Specifies the number of unsigned bytes of image data starting at the address specified by data.
data: Specifies a pointer to the compressed image data in memory.

Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable two-dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_2D. To enable and disable texturing using cube-mapped textures, call glEnable and glDisable with argument GL_TEXTURE_CUBE_MAP.

glCompressedTexImage2D loads a previously defined, and retrieved, compressed two-dimensional texture image if target is GL_TEXTURE_2D (see glTexImage2D).

If target is GL_PROXY_TEXTURE_2D, no data is read from data, but all of the texture image state is recalculated, checked for consistency, and checked against the implementation’s capabilities. If the implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but does not generate an error (see glGetError). To query for an entire mipmap array, use an image array level greater than or equal to 1.

internalformat must be an extension-specified compressed-texture format. When a texture is loaded with glTexImage2D using a generic compressed texture format (e.g., GL_COMPRESSED_RGB), the GL selects from one of its extensions supporting compressed textures. In order to load the compressed texture image using glCompressedTexImage2D, query the compressed texture image’s size and format using glGetTexLevelParameter.

GL_INVALID_VALUE is generated if imageSize is not consistent with the format, dimensions, and contents of the specified compressed image data.

GL_INVALID_OPERATION is generated if parameter combinations are not supported by the specific compressed internal format as specified in the specific texture compression extension.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glCompressedTexImage2D is executed between the execution of glBegin and the corresponding execution of glEnd.

Undefined results, including abnormal program termination, are generated if data is not encoded in a manner consistent with the extension specification defining the internal compression format.

Function: void glCompressedTexImage3D target level internalformat width height depth border imageSize data

Specify a three-dimensional texture image in a compressed format.

target: Specifies the target texture. Must be GL_TEXTURE_3D or GL_PROXY_TEXTURE_3D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
internalformat: Specifies the format of the compressed image data stored at address data.
width: Specifies the width of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^n+2â¡(border,) for some integer n. All implementations support 3D texture images that are at least 16 texels wide.
height: Specifies the height of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^n+2â¡(border,) for some integer n. All implementations support 3D texture images that are at least 16 texels high.
depth: Specifies the depth of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^n+2â¡(border,) for some integer n. All implementations support 3D texture images that are at least 16 texels deep.
border: Specifies the width of the border. Must be either 0 or 1.
imageSize: Specifies the number of unsigned bytes of image data starting at the address specified by data.
data: Specifies a pointer to the compressed image data in memory.

Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable three-dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_3D.

glCompressedTexImage3D loads a previously defined, and retrieved, compressed three-dimensional texture image if target is GL_TEXTURE_3D (see glTexImage3D).

If target is GL_PROXY_TEXTURE_3D, no data is read from data, but all of the texture image state is recalculated, checked for consistency, and checked against the implementation’s capabilities. If the implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but does not generate an error (see glGetError). To query for an entire mipmap array, use an image array level greater than or equal to 1.

internalformat must be an extension-specified compressed-texture format. When a texture is loaded with glTexImage2D using a generic compressed texture format (e.g., GL_COMPRESSED_RGB), the GL selects from one of its extensions supporting compressed textures. In order to load the compressed texture image using glCompressedTexImage3D, query the compressed texture image’s size and format using glGetTexLevelParameter.

GL_INVALID_VALUE is generated if imageSize is not consistent with the format, dimensions, and contents of the specified compressed image data.

GL_INVALID_OPERATION is generated if parameter combinations are not supported by the specific compressed internal format as specified in the specific texture compression extension.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glCompressedTexImage3D is executed between the execution of glBegin and the corresponding execution of glEnd.

Undefined results, including abnormal program termination, are generated if data is not encoded in a manner consistent with the extension specification defining the internal compression format.

Function: void glCompressedTexSubImage1D target level xoffset width format imageSize data

Specify a one-dimensional texture subimage in a compressed format.

target: Specifies the target texture. Must be GL_TEXTURE_1D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset: Specifies a texel offset in the x direction within the texture array.
width: Specifies the width of the texture subimage.
format: Specifies the format of the compressed image data stored at address data.
imageSize: Specifies the number of unsigned bytes of image data starting at the address specified by data.
data: Specifies a pointer to the compressed image data in memory.

glCompressedTexSubImage1D redefines a contiguous subregion of an existing one-dimensional texture image. The texels referenced by data replace the portion of the existing texture array with x indices xoffset and xoffset+width-1, inclusive. This region may not include any texels outside the range of the texture array as it was originally specified. It is not an error to specify a subtexture with width of 0, but such a specification has no effect.

format must be an extension-specified compressed-texture format. The format of the compressed texture image is selected by the GL implementation that compressed it (see glTexImage1D), and should be queried at the time the texture was compressed with glGetTexLevelParameter.

GL_INVALID_ENUM is generated if format is one of these generic compressed internal formats: GL_COMPRESSED_ALPHA, GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_INTENSITY, GL_COMPRESSED_RGB, GL_COMPRESSED_RGBA, GL_COMPRESSED_SLUMINANCE, GL_COMPRESSED_SLUMINANCE_ALPHA, GL_COMPRESSED_SRGB, GL_COMPRESSED_SRGBA, or GL_COMPRESSED_SRGB_ALPHA.

GL_INVALID_VALUE is generated if imageSize is not consistent with the format, dimensions, and contents of the specified compressed image data.

GL_INVALID_OPERATION is generated if parameter combinations are not supported by the specific compressed internal format as specified in the specific texture compression extension.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glCompressedTexSubImage1D is executed between the execution of glBegin and the corresponding execution of glEnd.

Undefined results, including abnormal program termination, are generated if data is not encoded in a manner consistent with the extension specification defining the internal compression format.

Function: void glCompressedTexSubImage2D target level xoffset yoffset width height format imageSize data

Specify a two-dimensional texture subimage in a compressed format.

target: Specifies the target texture. Must be GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset: Specifies a texel offset in the x direction within the texture array.
yoffset: Specifies a texel offset in the y direction within the texture array.
width: Specifies the width of the texture subimage.
height: Specifies the height of the texture subimage.
format: Specifies the format of the compressed image data stored at address data.
imageSize: Specifies the number of unsigned bytes of image data starting at the address specified by data.
data: Specifies a pointer to the compressed image data in memory.

Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable two-dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_2D. To enable and disable texturing using cube-mapped texture, call glEnable and glDisable with argument GL_TEXTURE_CUBE_MAP.

glCompressedTexSubImage2D redefines a contiguous subregion of an existing two-dimensional texture image. The texels referenced by data replace the portion of the existing texture array with x indices xoffset and xoffset+width-1, and the y indices yoffset and yoffset+height-1, inclusive. This region may not include any texels outside the range of the texture array as it was originally specified. It is not an error to specify a subtexture with width of 0, but such a specification has no effect.

format must be an extension-specified compressed-texture format. The format of the compressed texture image is selected by the GL implementation that compressed it (see glTexImage2D) and should be queried at the time the texture was compressed with glGetTexLevelParameter.

GL_INVALID_VALUE is generated if imageSize is not consistent with the format, dimensions, and contents of the specified compressed image data.

GL_INVALID_OPERATION is generated if parameter combinations are not supported by the specific compressed internal format as specified in the specific texture compression extension.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glCompressedTexSubImage2D is executed between the execution of glBegin and the corresponding execution of glEnd.

Undefined results, including abnormal program termination, are generated if data is not encoded in a manner consistent with the extension specification defining the internal compression format.

Function: void glCompressedTexSubImage3D target level xoffset yoffset zoffset width height depth format imageSize data

Specify a three-dimensional texture subimage in a compressed format.

target: Specifies the target texture. Must be GL_TEXTURE_3D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset: Specifies a texel offset in the x direction within the texture array.
yoffset: Specifies a texel offset in the y direction within the texture array.
width: Specifies the width of the texture subimage.
height: Specifies the height of the texture subimage.
depth: Specifies the depth of the texture subimage.
format: Specifies the format of the compressed image data stored at address data.
imageSize: Specifies the number of unsigned bytes of image data starting at the address specified by data.
data: Specifies a pointer to the compressed image data in memory.

glCompressedTexSubImage3D redefines a contiguous subregion of an existing three-dimensional texture image. The texels referenced by data replace the portion of the existing texture array with x indices xoffset and xoffset+width-1, and the y indices yoffset and yoffset+height-1, and the z indices zoffset and zoffset+depth-1, inclusive. This region may not include any texels outside the range of the texture array as it was originally specified. It is not an error to specify a subtexture with width of 0, but such a specification has no effect.

format must be an extension-specified compressed-texture format. The format of the compressed texture image is selected by the GL implementation that compressed it (see glTexImage3D) and should be queried at the time the texture was compressed with glGetTexLevelParameter.

GL_INVALID_VALUE is generated if imageSize is not consistent with the format, dimensions, and contents of the specified compressed image data.

GL_INVALID_OPERATION is generated if parameter combinations are not supported by the specific compressed internal format as specified in the specific texture compression extension.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glCompressedTexSubImage3D is executed between the execution of glBegin and the corresponding execution of glEnd.

Undefined results, including abnormal program termination, are generated if data is not encoded in a manner consistent with the extension specification defining the internal compression format.

Function: void glConvolutionFilter1D target internalformat width format type data

Define a one-dimensional convolution filter.

target: Must be GL_CONVOLUTION_1D.
internalformat: The internal format of the convolution filter kernel. The allowable values are GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
width: The width of the pixel array referenced by data.
format: The format of the pixel data in data. The allowable values are GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_INTENSITY, GL_RGB, and GL_RGBA.
type: The type of the pixel data in data. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
data: Pointer to a one-dimensional array of pixel data that is processed to build the convolution filter kernel.

glConvolutionFilter1D builds a one-dimensional convolution filter kernel from an array of pixels.

The pixel array specified by width, format, type, and data is extracted from memory and processed just as if glDrawPixels were called, but processing stops after the final expansion to RGBA is completed.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a convolution filter is specified, data is treated as a byte offset into the buffer object’s data store.

The R, G, B, and A components of each pixel are next scaled by the four 1D GL_CONVOLUTION_FILTER_SCALE parameters and biased by the four 1D GL_CONVOLUTION_FILTER_BIAS parameters. (The scale and bias parameters are set by glConvolutionParameter using the GL_CONVOLUTION_1D target and the names GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS. The parameters themselves are vectors of four values that are applied to red, green, blue, and alpha, in that order.) The R, G, B, and A values are not clamped to [0,1] at any time during this process.

Each pixel is then converted to the internal format specified by internalformat. This conversion simply maps the component values of the pixel (R, G, B, and A) to the values included in the internal format (red, green, blue, alpha, luminance, and intensity). The mapping is as follows:

Internal Format: Red, Green, Blue, Alpha, Luminance, Intensity
GL_ALPHA: , , , A , ,
GL_LUMINANCE: , , , , R ,
GL_LUMINANCE_ALPHA: , , , A , R ,
GL_INTENSITY: , , , , , R
GL_RGB: R , G , B , , ,
GL_RGBA: R , G , B , A , ,

The red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are stored in floating-point rather than integer format. They form a one-dimensional filter kernel image indexed with coordinate i such that i starts at 0 and increases from left to right. Kernel location i is derived from the ith pixel, counting from 0.

Note that after a convolution is performed, the resulting color components are also scaled by their corresponding GL_POST_CONVOLUTION_c_SCALE parameters and biased by their corresponding GL_POST_CONVOLUTION_c_BIAS parameters (where c takes on the values RED, GREEN, BLUE, and ALPHA). These parameters are set by glPixelTransfer.

GL_INVALID_ENUM is generated if target is not GL_CONVOLUTION_1D.

GL_INVALID_ENUM is generated if internalformat is not one of the allowable values.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if type is not one of the allowable values.

GL_INVALID_VALUE is generated if width is less than zero or greater than the maximum supported value. This value may be queried with glGetConvolutionParameter using target GL_CONVOLUTION_1D and name GL_MAX_CONVOLUTION_WIDTH.

GL_INVALID_OPERATION is generated if format is one of GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and type is not GL_RGB.

GL_INVALID_OPERATION is generated if format is one of GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and type is neither GL_RGBA nor GL_BGRA.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glConvolutionFilter1D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glConvolutionFilter2D target internalformat width height format type data

Define a two-dimensional convolution filter.

target: Must be GL_CONVOLUTION_2D.
internalformat: The internal format of the convolution filter kernel. The allowable values are GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
width: The width of the pixel array referenced by data.
height: The height of the pixel array referenced by data.
format: The format of the pixel data in data. The allowable values are GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: The type of the pixel data in data. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
data: Pointer to a two-dimensional array of pixel data that is processed to build the convolution filter kernel.

glConvolutionFilter2D builds a two-dimensional convolution filter kernel from an array of pixels.

The pixel array specified by width, height, format, type, and data is extracted from memory and processed just as if glDrawPixels were called, but processing stops after the final expansion to RGBA is completed.

The R, G, B, and A components of each pixel are next scaled by the four 2D GL_CONVOLUTION_FILTER_SCALE parameters and biased by the four 2D GL_CONVOLUTION_FILTER_BIAS parameters. (The scale and bias parameters are set by glConvolutionParameter using the GL_CONVOLUTION_2D target and the names GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS. The parameters themselves are vectors of four values that are applied to red, green, blue, and alpha, in that order.) The R, G, B, and A values are not clamped to [0,1] at any time during this process.

Internal Format: Red, Green, Blue, Alpha, Luminance, Intensity
GL_ALPHA: , , , A , ,
GL_LUMINANCE: , , , , R ,
GL_LUMINANCE_ALPHA: , , , A , R ,
GL_INTENSITY: , , , , , R
GL_RGB: R , G , B , , ,
GL_RGBA: R , G , B , A , ,

The red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are stored in floating-point rather than integer format. They form a two-dimensional filter kernel image indexed with coordinates i and j such that i starts at zero and increases from left to right, and j starts at zero and increases from bottom to top. Kernel location i,j is derived from the Nth pixel, where N is i+j*width.

GL_INVALID_ENUM is generated if target is not GL_CONVOLUTION_2D.

GL_INVALID_ENUM is generated if internalformat is not one of the allowable values.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if type is not one of the allowable values.

GL_INVALID_VALUE is generated if height is less than zero or greater than the maximum supported value. This value may be queried with glGetConvolutionParameter using target GL_CONVOLUTION_2D and name GL_MAX_CONVOLUTION_HEIGHT.

GL_INVALID_OPERATION is generated if height is one of GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB.

GL_INVALID_OPERATION is generated if height is one of GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and format is neither GL_RGBA nor GL_BGRA.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glConvolutionFilter2D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glConvolutionParameterf target pname params

Function: void glConvolutionParameteri target pname params

Function: void glConvolutionParameterfv target pname params

Function: void glConvolutionParameteriv target pname params

Set convolution parameters.

target: The target for the convolution parameter. Must be one of GL_CONVOLUTION_1D, GL_CONVOLUTION_2D, or GL_SEPARABLE_2D.
pname: The parameter to be set. Must be GL_CONVOLUTION_BORDER_MODE.
params: The parameter value. Must be one of GL_REDUCE, GL_CONSTANT_BORDER, GL_REPLICATE_BORDER.

glConvolutionParameter sets the value of a convolution parameter.

target selects the convolution filter to be affected: GL_CONVOLUTION_1D, GL_CONVOLUTION_2D, or GL_SEPARABLE_2D for the 1D, 2D, or separable 2D filter, respectively.

pname selects the parameter to be changed. GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS affect the definition of the convolution filter kernel; see glConvolutionFilter1D, glConvolutionFilter2D, and glSeparableFilter2D for details. In these cases, paramsv is an array of four values to be applied to red, green, blue, and alpha values, respectively. The initial value for GL_CONVOLUTION_FILTER_SCALE is (1, 1, 1, 1), and the initial value for GL_CONVOLUTION_FILTER_BIAS is (0, 0, 0, 0).

A pname value of GL_CONVOLUTION_BORDER_MODE controls the convolution border mode. The accepted modes are:

GL_REDUCE: The image resulting from convolution is smaller than the source image. If the filter width is Wf and height is Hf, and the source image width is Ws and height is Hs, then the convolved image width will be Ws-Wf+1 and height will be Hs-Hf+1. (If this reduction would generate an image with zero or negative width and/or height, the output is simply null, with no error generated.) The coordinates of the image resulting from convolution are zero through Ws-Wf in width and zero through Hs-Hf in height.
GL_CONSTANT_BORDER: The image resulting from convolution is the same size as the source image, and processed as if the source image were surrounded by pixels with their color specified by the GL_CONVOLUTION_BORDER_COLOR.
GL_REPLICATE_BORDER: The image resulting from convolution is the same size as the source image, and processed as if the outermost pixel on the border of the source image were replicated.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if pname is not one of the allowable values.

GL_INVALID_ENUM is generated if pname is GL_CONVOLUTION_BORDER_MODE and params is not one of GL_REDUCE, GL_CONSTANT_BORDER, or GL_REPLICATE_BORDER.

GL_INVALID_OPERATION is generated if glConvolutionParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCopyColorSubTable target start x y width

Respecify a portion of a color table.

target: Must be one of GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, or GL_POST_COLOR_MATRIX_COLOR_TABLE.
start: The starting index of the portion of the color table to be replaced.
x
y: The window coordinates of the left corner of the row of pixels to be copied.
width: The number of table entries to replace.

glCopyColorSubTable is used to respecify a contiguous portion of a color table previously defined using glColorTable. The pixels copied from the framebuffer replace the portion of the existing table from indices start to start+x-1, inclusive. This region may not include any entries outside the range of the color table, as was originally specified. It is not an error to specify a subtexture with width of 0, but such a specification has no effect.

GL_INVALID_VALUE is generated if target is not a previously defined color table.

GL_INVALID_VALUE is generated if target is not one of the allowable values.

GL_INVALID_VALUE is generated if start+x>width.

GL_INVALID_OPERATION is generated if glCopyColorSubTable is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCopyColorTable target internalformat x y width

Copy pixels into a color table.

target: The color table target. Must be GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, or GL_POST_COLOR_MATRIX_COLOR_TABLE.
internalformat: The internal storage format of the texture image. Must be one of the following symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
x: The x coordinate of the lower-left corner of the pixel rectangle to be transferred to the color table.
y: The y coordinate of the lower-left corner of the pixel rectangle to be transferred to the color table.
width: The width of the pixel rectangle.

glCopyColorTable loads a color table with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for glColorTable).

The screen-aligned pixel rectangle with lower-left corner at (x,\ y) having width width and height 1 is loaded into the color table. If any pixels within this region are outside the window that is associated with the GL context, the values obtained for those pixels are undefined.

The pixels in the rectangle are processed just as if glReadPixels were called, with internalformat set to RGBA, but processing stops after the final conversion to RGBA.

The four scale parameters and the four bias parameters that are defined for the table are then used to scale and bias the R, G, B, and A components of each pixel. The scale and bias parameters are set by calling glColorTableParameter.

Internal Format: Red, Green, Blue, Alpha, Luminance, Intensity
GL_ALPHA: , , , A , ,
GL_LUMINANCE: , , , , R ,
GL_LUMINANCE_ALPHA: , , , A , R ,
GL_INTENSITY: , , , , , R
GL_RGB: R , G , B , , ,
GL_RGBA: R , G , B , A , ,

GL_INVALID_ENUM is generated when target is not one of the allowable values.

GL_INVALID_VALUE is generated if width is less than zero.

GL_INVALID_VALUE is generated if internalformat is not one of the allowable values.

GL_TABLE_TOO_LARGE is generated if the requested color table is too large to be supported by the implementation.

GL_INVALID_OPERATION is generated if glCopyColorTable is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCopyConvolutionFilter1D target internalformat x y width

Copy pixels into a one-dimensional convolution filter.

target: Must be GL_CONVOLUTION_1D.
internalformat: The internal format of the convolution filter kernel. The allowable values are GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
x
y: The window space coordinates of the lower-left coordinate of the pixel array to copy.
width: The width of the pixel array to copy.

glCopyConvolutionFilter1D defines a one-dimensional convolution filter kernel with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for glConvolutionFilter1D).

The screen-aligned pixel rectangle with lower-left corner at (x,\ y), width width and height 1 is used to define the convolution filter. If any pixels within this region are outside the window that is associated with the GL context, the values obtained for those pixels are undefined.

The pixels in the rectangle are processed exactly as if glReadPixels had been called with format set to RGBA, but the process stops just before final conversion. The R, G, B, and A components of each pixel are next scaled by the four 1D GL_CONVOLUTION_FILTER_SCALE parameters and biased by the four 1D GL_CONVOLUTION_FILTER_BIAS parameters. (The scale and bias parameters are set by glConvolutionParameter using the GL_CONVOLUTION_1D target and the names GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS. The parameters themselves are vectors of four values that are applied to red, green, blue, and alpha, in that order.) The R, G, B, and A values are not clamped to [0,1] at any time during this process.

Internal Format: Red, Green, Blue, Alpha, Luminance, Intensity
GL_ALPHA: , , , A , ,
GL_LUMINANCE: , , , , R ,
GL_LUMINANCE_ALPHA: , , , A , R ,
GL_INTENSITY: , , , , , R
GL_RGB: R , G , B , , ,
GL_RGBA: R , G , B , A , ,

The red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are stored in floating-point rather than integer format.

Pixel ordering is such that lower x screen coordinates correspond to lower i filter image coordinates.

GL_INVALID_ENUM is generated if target is not GL_CONVOLUTION_1D.

GL_INVALID_ENUM is generated if internalformat is not one of the allowable values.

GL_INVALID_OPERATION is generated if glCopyConvolutionFilter1D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCopyConvolutionFilter2D target internalformat x y width height

Copy pixels into a two-dimensional convolution filter.

target: Must be GL_CONVOLUTION_2D.
internalformat: The internal format of the convolution filter kernel. The allowable values are GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
x
y: The window space coordinates of the lower-left coordinate of the pixel array to copy.
width: The width of the pixel array to copy.
height: The height of the pixel array to copy.

glCopyConvolutionFilter2D defines a two-dimensional convolution filter kernel with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for glConvolutionFilter2D).

The screen-aligned pixel rectangle with lower-left corner at (x,\ y), width width and height height is used to define the convolution filter. If any pixels within this region are outside the window that is associated with the GL context, the values obtained for those pixels are undefined.

The pixels in the rectangle are processed exactly as if glReadPixels had been called with format set to RGBA, but the process stops just before final conversion. The R, G, B, and A components of each pixel are next scaled by the four 2D GL_CONVOLUTION_FILTER_SCALE parameters and biased by the four 2D GL_CONVOLUTION_FILTER_BIAS parameters. (The scale and bias parameters are set by glConvolutionParameter using the GL_CONVOLUTION_2D target and the names GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS. The parameters themselves are vectors of four values that are applied to red, green, blue, and alpha, in that order.) The R, G, B, and A values are not clamped to [0,1] at any time during this process.

Internal Format: Red, Green, Blue, Alpha, Luminance, Intensity
GL_ALPHA: , , , A , ,
GL_LUMINANCE: , , , , R ,
GL_LUMINANCE_ALPHA: , , , A , R ,
GL_INTENSITY: , , , , , R
GL_RGB: R , G , B , , ,
GL_RGBA: R , G , B , A , ,

The red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are stored in floating-point rather than integer format.

Pixel ordering is such that lower x screen coordinates correspond to lower i filter image coordinates, and lower y screen coordinates correspond to lower j filter image coordinates.

GL_INVALID_ENUM is generated if target is not GL_CONVOLUTION_2D.

GL_INVALID_ENUM is generated if internalformat is not one of the allowable values.

GL_INVALID_OPERATION is generated if glCopyConvolutionFilter2D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCopyPixels x y width height type

Copy pixels in the frame buffer.

x
y: Specify the window coordinates of the lower left corner of the rectangular region of pixels to be copied.
width
height: Specify the dimensions of the rectangular region of pixels to be copied. Both must be nonnegative.
type: Specifies whether color values, depth values, or stencil values are to be copied. Symbolic constants GL_COLOR, GL_DEPTH, and GL_STENCIL are accepted.

glCopyPixels copies a screen-aligned rectangle of pixels from the specified frame buffer location to a region relative to the current raster position. Its operation is well defined only if the entire pixel source region is within the exposed portion of the window. Results of copies from outside the window, or from regions of the window that are not exposed, are hardware dependent and undefined.

x and y specify the window coordinates of the lower left corner of the rectangular region to be copied. width and height specify the dimensions of the rectangular region to be copied. Both width and height must not be negative.

Several parameters control the processing of the pixel data while it is being copied. These parameters are set with three commands: glPixelTransfer, glPixelMap, and glPixelZoom. This reference page describes the effects on glCopyPixels of most, but not all, of the parameters specified by these three commands.

glCopyPixels copies values from each pixel with the lower left-hand corner at (x+i,y+j) for 0<=i<width and 0<=j<height. This pixel is said to be the ith pixel in the jth row. Pixels are copied in row order from the lowest to the highest row, left to right in each row.

type specifies whether color, depth, or stencil data is to be copied. The details of the transfer for each data type are as follows:

GL_COLOR

Indices or RGBA colors are read from the buffer currently specified as the read source buffer (see glReadBuffer). If the GL is in color index mode, each index that is read from this buffer is converted to a fixed-point format with an unspecified number of bits to the right of the binary point. Each index is then shifted left by GL_INDEX_SHIFT bits, and added to GL_INDEX_OFFSET. If GL_INDEX_SHIFT is negative, the shift is to the right. In either case, zero bits fill otherwise unspecified bit locations in the result. If GL_MAP_COLOR is true, the index is replaced with the value that it references in lookup table GL_PIXEL_MAP_I_TO_I. Whether the lookup replacement of the index is done or not, the integer part of the index is then ANDed with 2^b-1, where b is the number of bits in a color index buffer.

If the GL is in RGBA mode, the red, green, blue, and alpha components of each pixel that is read are converted to an internal floating-point format with unspecified precision. The conversion maps the largest representable component value to 1.0, and component value 0 to 0.0. The resulting floating-point color values are then multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is RED, GREEN, BLUE, and ALPHA for the respective color components. The results are clamped to the range [0,1]. If GL_MAP_COLOR is true, each color component is scaled by the size of lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value that it references in that table. c is R, G, B, or A.

If the ARB_imaging extension is supported, the color values may be additionally processed by color-table lookups, color-matrix transformations, and convolution filters.

The GL then converts the resulting indices or RGBA colors to fragments by attaching the current raster position z coordinate and texture coordinates to each pixel, then assigning window coordinates (x_r+i,y_r+j), where (x_r,y_r) is the current raster position, and the pixel was the ith pixel in the jth row. These pixel fragments are then treated just like the fragments generated by rasterizing points, lines, or polygons. Texture mapping, fog, and all the fragment operations are applied before the fragments are written to the frame buffer.

GL_DEPTH

Depth values are read from the depth buffer and converted directly to an internal floating-point format with unspecified precision. The resulting floating-point depth value is then multiplied by GL_DEPTH_SCALE and added to GL_DEPTH_BIAS. The result is clamped to the range [0,1].

The GL then converts the resulting depth components to fragments by attaching the current raster position color or color index and texture coordinates to each pixel, then assigning window coordinates (x_r+i,y_r+j), where (x_r,y_r) is the current raster position, and the pixel was the ith pixel in the jth row. These pixel fragments are then treated just like the fragments generated by rasterizing points, lines, or polygons. Texture mapping, fog, and all the fragment operations are applied before the fragments are written to the frame buffer.

GL_STENCIL

Stencil indices are read from the stencil buffer and converted to an internal fixed-point format with an unspecified number of bits to the right of the binary point. Each fixed-point index is then shifted left by GL_INDEX_SHIFT bits, and added to GL_INDEX_OFFSET. If GL_INDEX_SHIFT is negative, the shift is to the right. In either case, zero bits fill otherwise unspecified bit locations in the result. If GL_MAP_STENCIL is true, the index is replaced with the value that it references in lookup table GL_PIXEL_MAP_S_TO_S. Whether the lookup replacement of the index is done or not, the integer part of the index is then ANDed with 2^b-1, where b is the number of bits in the stencil buffer. The resulting stencil indices are then written to the stencil buffer such that the index read from the ith location of the jth row is written to location (x_r+i,y_r+j), where (x_r,y_r) is the current raster position. Only the pixel ownership test, the scissor test, and the stencil writemask affect these write operations.

The rasterization described thus far assumes pixel zoom factors of 1.0. If glPixelZoom is used to change the x and y pixel zoom factors, pixels are converted to fragments as follows. If (x_r,y_r) is the current raster position, and a given pixel is in the ith location in the jth row of the source pixel rectangle, then fragments are generated for pixels whose centers are in the rectangle with corners at

(x_r+zoom_x,â¢i,y_r+zoom_y,â¢j)

and

(x_r+zoom_x,â¡(i+1,),y_r+zoom_y,â¡(j+1,))

where zoom_x is the value of GL_ZOOM_X and zoom_y is the value of GL_ZOOM_Y.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if either width or height is negative.

GL_INVALID_OPERATION is generated if type is GL_DEPTH and there is no depth buffer.

GL_INVALID_OPERATION is generated if type is GL_STENCIL and there is no stencil buffer.

GL_INVALID_OPERATION is generated if glCopyPixels is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCopyTexImage1D target level internalformat x y width border

Copy pixels into a 1D texture image.

target: Specifies the target texture. Must be GL_TEXTURE_1D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
internalformat: Specifies the internal format of the texture. Must be one of the following symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_COMPRESSED_ALPHA, GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_INTENSITY, GL_COMPRESSED_RGB, GL_COMPRESSED_RGBA, GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, GL_DEPTH_COMPONENT32, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_RGB, GL_R3_G3_B2, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, GL_RGBA16, GL_SLUMINANCE, GL_SLUMINANCE8, GL_SLUMINANCE_ALPHA, GL_SLUMINANCE8_ALPHA8, GL_SRGB, GL_SRGB8, GL_SRGB_ALPHA, or GL_SRGB8_ALPHA8.
x
y: Specify the window coordinates of the left corner of the row of pixels to be copied.
width: Specifies the width of the texture image. Must be 0 or 2^n+2â¡(border,) for some integer n. The height of the texture image is 1.
border: Specifies the width of the border. Must be either 0 or 1.

glCopyTexImage1D defines a one-dimensional texture image with pixels from the current GL_READ_BUFFER.

The screen-aligned pixel row with left corner at (x,y) and with a length of width+2â¡(border,) defines the texture array at the mipmap level specified by level. internalformat specifies the internal format of the texture array.

The pixels in the row are processed exactly as if glCopyPixels had been called, but the process stops just before final conversion. At this point all pixel component values are clamped to the range [0,1] and then converted to the texture’s internal format for storage in the texel array.

Pixel ordering is such that lower x screen coordinates correspond to lower texture coordinates.

If any of the pixels within the specified row of the current GL_READ_BUFFER are outside the window associated with the current rendering context, then the values obtained for those pixels are undefined.

glCopyTexImage1D defines a one-dimensional texture image with pixels from the current GL_READ_BUFFER.

When internalformat is one of the sRGB types, the GL does not automatically convert the source pixels to the sRGB color space. In this case, the glPixelMap function can be used to accomplish the conversion.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2â¢max, where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if internalformat is not an allowable value.

GL_INVALID_VALUE is generated if width is less than 0 or greater than 2 + GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if non-power-of-two textures are not supported and the width cannot be represented as 2^n+2â¡(border,) for some integer value of n.

GL_INVALID_VALUE is generated if border is not 0 or 1.

GL_INVALID_OPERATION is generated if glCopyTexImage1D is executed between the execution of glBegin and the corresponding execution of glEnd.

GL_INVALID_OPERATION is generated if internalformat is GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT32 and there is no depth buffer.

Function: void glCopyTexImage2D target level internalformat x y width height border

Copy pixels into a 2D texture image.

target: Specifies the target texture. Must be GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
internalformat: Specifies the internal format of the texture. Must be one of the following symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_COMPRESSED_ALPHA, GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_INTENSITY, GL_COMPRESSED_RGB, GL_COMPRESSED_RGBA, GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, GL_DEPTH_COMPONENT32, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_RGB, GL_R3_G3_B2, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, GL_RGBA16, GL_SLUMINANCE, GL_SLUMINANCE8, GL_SLUMINANCE_ALPHA, GL_SLUMINANCE8_ALPHA8, GL_SRGB, GL_SRGB8, GL_SRGB_ALPHA, or GL_SRGB8_ALPHA8.
x
y: Specify the window coordinates of the lower left corner of the rectangular region of pixels to be copied.
width: Specifies the width of the texture image. Must be 0 or 2^n+2â¡(border,) for some integer n.
height: Specifies the height of the texture image. Must be 0 or 2^m+2â¡(border,) for some integer m.
border: Specifies the width of the border. Must be either 0 or 1.

glCopyTexImage2D defines a two-dimensional texture image, or cube-map texture image with pixels from the current GL_READ_BUFFER.

The screen-aligned pixel rectangle with lower left corner at (x, y) and with a width of width+2â¡(border,) and a height of height+2â¡(border,) defines the texture array at the mipmap level specified by level. internalformat specifies the internal format of the texture array.

The pixels in the rectangle are processed exactly as if glCopyPixels had been called, but the process stops just before final conversion. At this point all pixel component values are clamped to the range [0,1] and then converted to the texture’s internal format for storage in the texel array.

Pixel ordering is such that lower x and y screen coordinates correspond to lower s and t texture coordinates.

If any of the pixels within the specified rectangle of the current GL_READ_BUFFER are outside the window associated with the current rendering context, then the values obtained for those pixels are undefined.

GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2â¢max, where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if width is less than 0 or greater than 2 + GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if non-power-of-two textures are not supported and the width or depth cannot be represented as 2^k+2â¡(border,) for some integer k.

GL_INVALID_VALUE is generated if border is not 0 or 1.

GL_INVALID_VALUE is generated if internalformat is not an accepted format.

GL_INVALID_OPERATION is generated if glCopyTexImage2D is executed between the execution of glBegin and the corresponding execution of glEnd.

GL_INVALID_OPERATION is generated if internalformat is GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT32 and there is no depth buffer.

Function: void glCopyTexSubImage1D target level xoffset x y width

Copy a one-dimensional texture subimage.

target: Specifies the target texture. Must be GL_TEXTURE_1D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset: Specifies the texel offset within the texture array.
x
y: Specify the window coordinates of the left corner of the row of pixels to be copied.
width: Specifies the width of the texture subimage.

glCopyTexSubImage1D replaces a portion of a one-dimensional texture image with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for glTexSubImage1D).

The screen-aligned pixel row with left corner at (x,\ y), and with length width replaces the portion of the texture array with x indices xoffset through xoffset+width-1, inclusive. The destination in the texture array may not include any texels outside the texture array as it was originally specified.

The pixels in the row are processed exactly as if glCopyPixels had been called, but the process stops just before final conversion. At this point, all pixel component values are clamped to the range [0,1] and then converted to the texture’s internal format for storage in the texel array.

It is not an error to specify a subtexture with zero width, but such a specification has no effect. If any of the pixels within the specified row of the current GL_READ_BUFFER are outside the read window associated with the current rendering context, then the values obtained for those pixels are undefined.

No change is made to the internalformat, width, or border parameters of the specified texture array or to texel values outside the specified subregion.

GL_INVALID_ENUM is generated if /target is not GL_TEXTURE_1D.

GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage1D or glCopyTexImage1D operation.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level>log_2â¡(max,), where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if xoffset<-b, or (xoffset+width,)>(w-b,), where w is the GL_TEXTURE_WIDTH and b is the GL_TEXTURE_BORDER of the texture image being modified. Note that w includes twice the border width.

Function: void glCopyTexSubImage2D target level xoffset yoffset x y width height

Copy a two-dimensional texture subimage.

target: Specifies the target texture. Must be GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset: Specifies a texel offset in the x direction within the texture array.
yoffset: Specifies a texel offset in the y direction within the texture array.
x
y: Specify the window coordinates of the lower left corner of the rectangular region of pixels to be copied.
width: Specifies the width of the texture subimage.
height: Specifies the height of the texture subimage.

glCopyTexSubImage2D replaces a rectangular portion of a two-dimensional texture image or cube-map texture image with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for glTexSubImage2D).

The screen-aligned pixel rectangle with lower left corner at (x,y) and with width width and height height replaces the portion of the texture array with x indices xoffset through xoffset+width-1, inclusive, and y indices yoffset through yoffset+height-1, inclusive, at the mipmap level specified by level.

The pixels in the rectangle are processed exactly as if glCopyPixels had been called, but the process stops just before final conversion. At this point, all pixel component values are clamped to the range [0,1] and then converted to the texture’s internal format for storage in the texel array.

The destination rectangle in the texture array may not include any texels outside the texture array as it was originally specified. It is not an error to specify a subtexture with zero width or height, but such a specification has no effect.

If any of the pixels within the specified rectangle of the current GL_READ_BUFFER are outside the read window associated with the current rendering context, then the values obtained for those pixels are undefined.

No change is made to the internalformat, width, height, or border parameters of the specified texture array or to texel values outside the specified subregion.

GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage2D or glCopyTexImage2D operation.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level>log_2â¡(max,), where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if xoffset<-b, (xoffset+width,)>(w-b,), yoffset<-b, or (yoffset+height,)>(h-b,), where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, and b is the GL_TEXTURE_BORDER of the texture image being modified. Note that w and h include twice the border width.

GL_INVALID_OPERATION is generated if glCopyTexSubImage2D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCopyTexSubImage3D target level xoffset yoffset zoffset x y width height

Copy a three-dimensional texture subimage.

target: Specifies the target texture. Must be GL_TEXTURE_3D
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset: Specifies a texel offset in the x direction within the texture array.
yoffset: Specifies a texel offset in the y direction within the texture array.
zoffset: Specifies a texel offset in the z direction within the texture array.
x
y: Specify the window coordinates of the lower left corner of the rectangular region of pixels to be copied.
width: Specifies the width of the texture subimage.
height: Specifies the height of the texture subimage.

glCopyTexSubImage3D replaces a rectangular portion of a three-dimensional texture image with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for glTexSubImage3D).

The screen-aligned pixel rectangle with lower left corner at (x,\ y) and with width width and height height replaces the portion of the texture array with x indices xoffset through xoffset+width-1, inclusive, and y indices yoffset through yoffset+height-1, inclusive, at z index zoffset and at the mipmap level specified by level.

No change is made to the internalformat, width, height, depth, or border parameters of the specified texture array or to texel values outside the specified subregion.

GL_INVALID_ENUM is generated if /target is not GL_TEXTURE_3D.

GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage3D operation.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level>log_2â¡(max,), where max is the returned value of GL_MAX_3D_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if xoffset<-b, (xoffset+width,)>(w-b,), yoffset<-b, (yoffset+height,)>(h-b,), zoffset<-b, or (zoffset+1,)>(d-b,), where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, d is the GL_TEXTURE_DEPTH, and b is the GL_TEXTURE_BORDER of the texture image being modified. Note that w, h, and d include twice the border width.

GL_INVALID_OPERATION is generated if glCopyTexSubImage3D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLuint glCreateProgram

Creates a program object.

glCreateProgram creates an empty program object and returns a non-zero value by which it can be referenced. A program object is an object to which shader objects can be attached. This provides a mechanism to specify the shader objects that will be linked to create a program. It also provides a means for checking the compatibility of the shaders that will be used to create a program (for instance, checking the compatibility between a vertex shader and a fragment shader). When no longer needed as part of a program object, shader objects can be detached.

One or more executables are created in a program object by successfully attaching shader objects to it with glAttachShader, successfully compiling the shader objects with glCompileShader, and successfully linking the program object with glLinkProgram. These executables are made part of current state when glUseProgram is called. Program objects can be deleted by calling glDeleteProgram. The memory associated with the program object will be deleted when it is no longer part of current rendering state for any context.

This function returns 0 if an error occurs creating the program object.

GL_INVALID_OPERATION is generated if glCreateProgram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLuint glCreateShader shaderType

Creates a shader object.

shaderType: Specifies the type of shader to be created. Must be either GL_VERTEX_SHADER or GL_FRAGMENT_SHADER.

glCreateShader creates an empty shader object and returns a non-zero value by which it can be referenced. A shader object is used to maintain the source code strings that define a shader. shaderType indicates the type of shader to be created. Two types of shaders are supported. A shader of type GL_VERTEX_SHADER is a shader that is intended to run on the programmable vertex processor and replace the fixed functionality vertex processing in OpenGL. A shader of type GL_FRAGMENT_SHADER is a shader that is intended to run on the programmable fragment processor and replace the fixed functionality fragment processing in OpenGL.

When created, a shader object’s GL_SHADER_TYPE parameter is set to either GL_VERTEX_SHADER or GL_FRAGMENT_SHADER, depending on the value of shaderType.

This function returns 0 if an error occurs creating the shader object.

GL_INVALID_ENUM is generated if shaderType is not an accepted value.

GL_INVALID_OPERATION is generated if glCreateShader is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glCullFace mode

Specify whether front- or back-facing facets can be culled.

mode: Specifies whether front- or back-facing facets are candidates for culling. Symbolic constants GL_FRONT, GL_BACK, and GL_FRONT_AND_BACK are accepted. The initial value is GL_BACK.

glCullFace specifies whether front- or back-facing facets are culled (as specified by mode) when facet culling is enabled. Facet culling is initially disabled. To enable and disable facet culling, call the glEnable and glDisable commands with the argument GL_CULL_FACE. Facets include triangles, quadrilaterals, polygons, and rectangles.

glFrontFace specifies which of the clockwise and counterclockwise facets are front-facing and back-facing. See glFrontFace.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_OPERATION is generated if glCullFace is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDeleteBuffers n buffers

Delete named buffer objects.

n: Specifies the number of buffer objects to be deleted.
buffers: Specifies an array of buffer objects to be deleted.

glDeleteBuffers deletes n buffer objects named by the elements of the array buffers. After a buffer object is deleted, it has no contents, and its name is free for reuse (for example by glGenBuffers). If a buffer object that is currently bound is deleted, the binding reverts to 0 (the absence of any buffer object, which reverts to client memory usage).

glDeleteBuffers silently ignores 0’s and names that do not correspond to existing buffer objects.

GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_OPERATION is generated if glDeleteBuffers is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDeleteLists list range

Delete a contiguous group of display lists.

list: Specifies the integer name of the first display list to delete.
range: Specifies the number of display lists to delete.

glDeleteLists causes a contiguous group of display lists to be deleted. list is the name of the first display list to be deleted, and range is the number of display lists to delete. All display lists d with list<=d<=list+range-1 are deleted.

All storage locations allocated to the specified display lists are freed, and the names are available for reuse at a later time. Names within the range that do not have an associated display list are ignored. If range is 0, nothing happens.

GL_INVALID_VALUE is generated if range is negative.

GL_INVALID_OPERATION is generated if glDeleteLists is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDeleteProgram program

Deletes a program object.

program: Specifies the program object to be deleted.

glDeleteProgram frees the memory and invalidates the name associated with the program object specified by program. This command effectively undoes the effects of a call to glCreateProgram.

If a program object is in use as part of current rendering state, it will be flagged for deletion, but it will not be deleted until it is no longer part of current state for any rendering context. If a program object to be deleted has shader objects attached to it, those shader objects will be automatically detached but not deleted unless they have already been flagged for deletion by a previous call to glDeleteShader. A value of 0 for program will be silently ignored.

To determine whether a program object has been flagged for deletion, call glGetProgram with arguments program and GL_DELETE_STATUS.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if glDeleteProgram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDeleteQueries n ids

Delete named query objects.

n: Specifies the number of query objects to be deleted.
ids: Specifies an array of query objects to be deleted.

glDeleteQueries deletes n query objects named by the elements of the array ids. After a query object is deleted, it has no contents, and its name is free for reuse (for example by glGenQueries).

glDeleteQueries silently ignores 0’s and names that do not correspond to existing query objects.

GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_OPERATION is generated if glDeleteQueries is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDeleteShader shader

Deletes a shader object.

shader: Specifies the shader object to be deleted.

glDeleteShader frees the memory and invalidates the name associated with the shader object specified by shader. This command effectively undoes the effects of a call to glCreateShader.

If a shader object to be deleted is attached to a program object, it will be flagged for deletion, but it will not be deleted until it is no longer attached to any program object, for any rendering context (i.e., it must be detached from wherever it was attached before it will be deleted). A value of 0 for shader will be silently ignored.

To determine whether an object has been flagged for deletion, call glGetShader with arguments shader and GL_DELETE_STATUS.

GL_INVALID_VALUE is generated if shader is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if glDeleteShader is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDeleteTextures n textures

Delete named textures.

n: Specifies the number of textures to be deleted.
textures: Specifies an array of textures to be deleted.

glDeleteTextures deletes n textures named by the elements of the array textures. After a texture is deleted, it has no contents or dimensionality, and its name is free for reuse (for example by glGenTextures). If a texture that is currently bound is deleted, the binding reverts to 0 (the default texture).

glDeleteTextures silently ignores 0’s and names that do not correspond to existing textures.

GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_OPERATION is generated if glDeleteTextures is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDepthFunc func

Specify the value used for depth buffer comparisons.

func: Specifies the depth comparison function. Symbolic constants GL_NEVER, GL_LESS, GL_EQUAL, GL_LEQUAL, GL_GREATER, GL_NOTEQUAL, GL_GEQUAL, and GL_ALWAYS are accepted. The initial value is GL_LESS.

glDepthFunc specifies the function used to compare each incoming pixel depth value with the depth value present in the depth buffer. The comparison is performed only if depth testing is enabled. (See glEnable and glDisable of GL_DEPTH_TEST.)

func specifies the conditions under which the pixel will be drawn. The comparison functions are as follows:

GL_NEVER: Never passes.
GL_LESS: Passes if the incoming depth value is less than the stored depth value.
GL_EQUAL: Passes if the incoming depth value is equal to the stored depth value.
GL_LEQUAL: Passes if the incoming depth value is less than or equal to the stored depth value.
GL_GREATER: Passes if the incoming depth value is greater than the stored depth value.
GL_NOTEQUAL: Passes if the incoming depth value is not equal to the stored depth value.
GL_GEQUAL: Passes if the incoming depth value is greater than or equal to the stored depth value.
GL_ALWAYS: Always passes.

The initial value of func is GL_LESS. Initially, depth testing is disabled. If depth testing is disabled or if no depth buffer exists, it is as if the depth test always passes.

GL_INVALID_ENUM is generated if func is not an accepted value.

GL_INVALID_OPERATION is generated if glDepthFunc is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDepthMask flag

Enable or disable writing into the depth buffer.

flag: Specifies whether the depth buffer is enabled for writing. If flag is GL_FALSE, depth buffer writing is disabled. Otherwise, it is enabled. Initially, depth buffer writing is enabled.

glDepthMask specifies whether the depth buffer is enabled for writing. If flag is GL_FALSE, depth buffer writing is disabled. Otherwise, it is enabled. Initially, depth buffer writing is enabled.

GL_INVALID_OPERATION is generated if glDepthMask is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDepthRange nearVal farVal

Specify mapping of depth values from normalized device coordinates to window coordinates.

nearVal: Specifies the mapping of the near clipping plane to window coordinates. The initial value is 0.
farVal: Specifies the mapping of the far clipping plane to window coordinates. The initial value is 1.

After clipping and division by w, depth coordinates range from -1 to 1, corresponding to the near and far clipping planes. glDepthRange specifies a linear mapping of the normalized depth coordinates in this range to window depth coordinates. Regardless of the actual depth buffer implementation, window coordinate depth values are treated as though they range from 0 through 1 (like color components). Thus, the values accepted by glDepthRange are both clamped to this range before they are accepted.

The setting of (0,1) maps the near plane to 0 and the far plane to 1. With this mapping, the depth buffer range is fully utilized.

GL_INVALID_OPERATION is generated if glDepthRange is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDetachShader program shader

Detaches a shader object from a program object to which it is attached.

program: Specifies the program object from which to detach the shader object.
shader: Specifies the shader object to be detached.

glDetachShader detaches the shader object specified by shader from the program object specified by program. This command can be used to undo the effect of the command glAttachShader.

If shader has already been flagged for deletion by a call to glDeleteShader and it is not attached to any other program object, it will be deleted after it has been detached.

GL_INVALID_VALUE is generated if either program or shader is a value that was not generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_OPERATION is generated if shader is not a shader object.

GL_INVALID_OPERATION is generated if shader is not attached to program.

GL_INVALID_OPERATION is generated if glDetachShader is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDrawArrays mode first count

Render primitives from array data.

mode: Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES, GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
first: Specifies the starting index in the enabled arrays.
count: Specifies the number of indices to be rendered.

glDrawArrays specifies multiple geometric primitives with very few subroutine calls. Instead of calling a GL procedure to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify separate arrays of vertices, normals, and colors and use them to construct a sequence of primitives with a single call to glDrawArrays.

When glDrawArrays is called, it uses count sequential elements from each enabled array to construct a sequence of geometric primitives, beginning with element first. mode specifies what kind of primitives are constructed and how the array elements construct those primitives. If GL_VERTEX_ARRAY is not enabled, no geometric primitives are generated.

Vertex attributes that are modified by glDrawArrays have an unspecified value after glDrawArrays returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current color is undefined after glDrawArrays executes. Attributes that aren’t modified remain well defined.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_VALUE is generated if count is negative.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glDrawArrays is executed between the execution of glBegin and the corresponding glEnd.

Function: void glDrawBuffers n bufs

Specifies a list of color buffers to be drawn into.

n: Specifies the number of buffers in bufs.
bufs: Points to an array of symbolic constants specifying the buffers into which fragment colors or data values will be written.

glDrawBuffers defines an array of buffers into which fragment color values or fragment data will be written. If no fragment shader is active, rendering operations will generate only one fragment color per fragment and it will be written into each of the buffers specified by bufs. If a fragment shader is active and it writes a value to the output variable gl_FragColor, then that value will be written into each of the buffers specified by bufs. If a fragment shader is active and it writes a value to one or more elements of the output array variable gl_FragData[], then the value of gl_FragData[0] will be written into the first buffer specified by bufs, the value of gl_FragData[1] will be written into the second buffer specified by bufs, and so on up to gl_FragData[n-1]. The draw buffer used for gl_FragData[n] and beyond is implicitly set to be GL_NONE.

The symbolic constants contained in bufs may be any of the following:

GL_NONE: The fragment color/data value is not written into any color buffer.
GL_FRONT_LEFT: The fragment color/data value is written into the front left color buffer.
GL_FRONT_RIGHT: The fragment color/data value is written into the front right color buffer.
GL_BACK_LEFT: The fragment color/data value is written into the back left color buffer.
GL_BACK_RIGHT: The fragment color/data value is written into the back right color buffer.
GL_AUXi: The fragment color/data value is written into auxiliary buffer i.

Except for GL_NONE, the preceding symbolic constants may not appear more than once in bufs. The maximum number of draw buffers supported is implementation dependent and can be queried by calling glGet with the argument GL_MAX_DRAW_BUFFERS. The number of auxiliary buffers can be queried by calling glGet with the argument GL_AUX_BUFFERS.

GL_INVALID_ENUM is generated if one of the values in bufs is not an accepted value.

GL_INVALID_ENUM is generated if n is less than 0.

GL_INVALID_OPERATION is generated if a symbolic constant other than GL_NONE appears more than once in bufs.

GL_INVALID_OPERATION is generated if any of the entries in bufs (other than GL_NONE ) indicates a color buffer that does not exist in the current GL context.

GL_INVALID_VALUE is generated if n is greater than GL_MAX_DRAW_BUFFERS.

GL_INVALID_OPERATION is generated if glDrawBuffers is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDrawBuffer mode

Specify which color buffers are to be drawn into.

mode: Specifies up to four color buffers to be drawn into. Symbolic constants GL_NONE, GL_FRONT_LEFT, GL_FRONT_RIGHT, GL_BACK_LEFT, GL_BACK_RIGHT, GL_FRONT, GL_BACK, GL_LEFT, GL_RIGHT, GL_FRONT_AND_BACK, and GL_AUXi, where i is between 0 and the value of GL_AUX_BUFFERS minus 1, are accepted. (GL_AUX_BUFFERS is not the upper limit; use glGet to query the number of available aux buffers.) The initial value is GL_FRONT for single-buffered contexts, and GL_BACK for double-buffered contexts.

When colors are written to the frame buffer, they are written into the color buffers specified by glDrawBuffer. The specifications are as follows:

GL_NONE: No color buffers are written.
GL_FRONT_LEFT: Only the front left color buffer is written.
GL_FRONT_RIGHT: Only the front right color buffer is written.
GL_BACK_LEFT: Only the back left color buffer is written.
GL_BACK_RIGHT: Only the back right color buffer is written.
GL_FRONT: Only the front left and front right color buffers are written. If there is no front right color buffer, only the front left color buffer is written.
GL_BACK: Only the back left and back right color buffers are written. If there is no back right color buffer, only the back left color buffer is written.
GL_LEFT: Only the front left and back left color buffers are written. If there is no back left color buffer, only the front left color buffer is written.
GL_RIGHT: Only the front right and back right color buffers are written. If there is no back right color buffer, only the front right color buffer is written.
GL_FRONT_AND_BACK: All the front and back color buffers (front left, front right, back left, back right) are written. If there are no back color buffers, only the front left and front right color buffers are written. If there are no right color buffers, only the front left and back left color buffers are written. If there are no right or back color buffers, only the front left color buffer is written.
GL_AUXi: Only auxiliary color buffer i is written.

If more than one color buffer is selected for drawing, then blending or logical operations are computed and applied independently for each color buffer and can produce different results in each buffer.

Monoscopic contexts include only left buffers, and stereoscopic contexts include both left and right buffers. Likewise, single-buffered contexts include only front buffers, and double-buffered contexts include both front and back buffers. The context is selected at GL initialization.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_OPERATION is generated if none of the buffers indicated by mode exists.

GL_INVALID_OPERATION is generated if glDrawBuffer is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDrawElements mode count type indices

Render primitives from array data.

mode: Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES, GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
count: Specifies the number of elements to be rendered.
type: Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.
indices: Specifies a pointer to the location where the indices are stored.

glDrawElements specifies multiple geometric primitives with very few subroutine calls. Instead of calling a GL function to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify separate arrays of vertices, normals, and so on, and use them to construct a sequence of primitives with a single call to glDrawElements.

When glDrawElements is called, it uses count sequential elements from an enabled array, starting at indices to construct a sequence of geometric primitives. mode specifies what kind of primitives are constructed and how the array elements construct these primitives. If more than one array is enabled, each is used. If GL_VERTEX_ARRAY is not enabled, no geometric primitives are constructed.

Vertex attributes that are modified by glDrawElements have an unspecified value after glDrawElements returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current color is undefined after glDrawElements executes. Attributes that aren’t modified maintain their previous values.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_VALUE is generated if count is negative.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array or the element array and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glDrawElements is executed between the execution of glBegin and the corresponding glEnd.

Function: void glDrawPixels width height format type data

Write a block of pixels to the frame buffer.

width
height: Specify the dimensions of the pixel rectangle to be written into the frame buffer.
format: Specifies the format of the pixel data. Symbolic constants GL_COLOR_INDEX, GL_STENCIL_INDEX, GL_DEPTH_COMPONENT, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA are accepted.
type: Specifies the data type for data. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
data: Specifies a pointer to the pixel data.

glDrawPixels reads pixel data from memory and writes it into the frame buffer relative to the current raster position, provided that the raster position is valid. Use glRasterPos or glWindowPos to set the current raster position; use glGet with argument GL_CURRENT_RASTER_POSITION_VALID to determine if the specified raster position is valid, and glGet with argument GL_CURRENT_RASTER_POSITION to query the raster position.

Several parameters define the encoding of pixel data in memory and control the processing of the pixel data before it is placed in the frame buffer. These parameters are set with four commands: glPixelStore, glPixelTransfer, glPixelMap, and glPixelZoom. This reference page describes the effects on glDrawPixels of many, but not all, of the parameters specified by these four commands.

Data is read from data as a sequence of signed or unsigned bytes, signed or unsigned shorts, signed or unsigned integers, or single-precision floating-point values, depending on type. When type is one of GL_UNSIGNED_BYTE, GL_BYTE, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, or GL_FLOAT each of these bytes, shorts, integers, or floating-point values is interpreted as one color or depth component, or one index, depending on format. When type is one of GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_INT_8_8_8_8, or GL_UNSIGNED_INT_10_10_10_2, each unsigned value is interpreted as containing all the components for a single pixel, with the color components arranged according to format. When type is one of GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8_REV, or GL_UNSIGNED_INT_2_10_10_10_REV, each unsigned value is interpreted as containing all color components, specified by format, for a single pixel in a reversed order. Indices are always treated individually. Color components are treated as groups of one, two, three, or four values, again based on format. Both individual indices and groups of components are referred to as pixels. If type is GL_BITMAP, the data must be unsigned bytes, and format must be either GL_COLOR_INDEX or GL_STENCIL_INDEX. Each unsigned byte is treated as eight 1-bit pixels, with bit ordering determined by GL_UNPACK_LSB_FIRST (see glPixelStore).

widthÃheight pixels are read from memory, starting at location data. By default, these pixels are taken from adjacent memory locations, except that after all width pixels are read, the read pointer is advanced to the next four-byte boundary. The four-byte row alignment is specified by glPixelStore with argument GL_UNPACK_ALIGNMENT, and it can be set to one, two, four, or eight bytes. Other pixel store parameters specify different read pointer advancements, both before the first pixel is read and after all width pixels are read. See the glPixelStore reference page for details on these options.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a block of pixels is specified, data is treated as a byte offset into the buffer object’s data store.

The widthÃheight pixels that are read from memory are each operated on in the same way, based on the values of several parameters specified by glPixelTransfer and glPixelMap. The details of these operations, as well as the target buffer into which the pixels are drawn, are specific to the format of the pixels, as specified by format. format can assume one of 13 symbolic values:

GL_COLOR_INDEX

Each pixel is a single value, a color index. It is converted to fixed-point format, with an unspecified number of bits to the right of the binary point, regardless of the memory data type. Floating-point values convert to true fixed-point values. Signed and unsigned integer data is converted with all fraction bits set to 0. Bitmap data convert to either 0 or 1.

Each fixed-point index is then shifted left by GL_INDEX_SHIFT bits and added to GL_INDEX_OFFSET. If GL_INDEX_SHIFT is negative, the shift is to the right. In either case, zero bits fill otherwise unspecified bit locations in the result.

If the GL is in RGBA mode, the resulting index is converted to an RGBA pixel with the help of the GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and GL_PIXEL_MAP_I_TO_A tables. If the GL is in color index mode, and if GL_MAP_COLOR is true, the index is replaced with the value that it references in lookup table GL_PIXEL_MAP_I_TO_I. Whether the lookup replacement of the index is done or not, the integer part of the index is then ANDed with 2^b-1, where b is the number of bits in a color index buffer.

where (x_r,y_r) is the current raster position. These pixel fragments are then treated just like the fragments generated by rasterizing points, lines, or polygons. Texture mapping, fog, and all the fragment operations are applied before the fragments are written to the frame buffer.

GL_STENCIL_INDEX

Each pixel is a single value, a stencil index. It is converted to fixed-point format, with an unspecified number of bits to the right of the binary point, regardless of the memory data type. Floating-point values convert to true fixed-point values. Signed and unsigned integer data is converted with all fraction bits set to 0. Bitmap data convert to either 0 or 1.

Each fixed-point index is then shifted left by GL_INDEX_SHIFT bits, and added to GL_INDEX_OFFSET. If GL_INDEX_SHIFT is negative, the shift is to the right. In either case, zero bits fill otherwise unspecified bit locations in the result. If GL_MAP_STENCIL is true, the index is replaced with the value that it references in lookup table GL_PIXEL_MAP_S_TO_S. Whether the lookup replacement of the index is done or not, the integer part of the index is then ANDed with 2^b-1, where b is the number of bits in the stencil buffer. The resulting stencil indices are then written to the stencil buffer such that the nth index is written to location

x_n=x_r+n%widthy_n=y_r+ân/width,â

where (x_r,y_r) is the current raster position. Only the pixel ownership test, the scissor test, and the stencil writemask affect these write operations.

GL_DEPTH_COMPONENT

Each pixel is a single-depth component. Floating-point data is converted directly to an internal floating-point format with unspecified precision. Signed integer data is mapped linearly to the internal floating-point format such that the most positive representable integer value maps to 1.0, and the most negative representable value maps to -1.0. Unsigned integer data is mapped similarly: the largest integer value maps to 1.0, and 0 maps to 0.0. The resulting floating-point depth value is then multiplied by GL_DEPTH_SCALE and added to GL_DEPTH_BIAS. The result is clamped to the range [0,1].

x_n=x_r+n%widthy_n=y_r+ân/width,â

GL_RGBA

GL_BGRA

Each pixel is a four-component group: For GL_RGBA, the red component is first, followed by green, followed by blue, followed by alpha; for GL_BGRA the order is blue, green, red and then alpha. Floating-point values are converted directly to an internal floating-point format with unspecified precision. Signed integer values are mapped linearly to the internal floating-point format such that the most positive representable integer value maps to 1.0, and the most negative representable value maps to -1.0. (Note that this mapping does not convert 0 precisely to 0.0.) Unsigned integer data is mapped similarly: The largest integer value maps to 1.0, and 0 maps to 0.0. The resulting floating-point color values are then multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is RED, GREEN, BLUE, and ALPHA for the respective color components. The results are clamped to the range [0,1].

If GL_MAP_COLOR is true, each color component is scaled by the size of lookup table GL_PIXEL_MAP_c_TO_c, then replaced by the value that it references in that table. c is R, G, B, or A respectively.

The GL then converts the resulting RGBA colors to fragments by attaching the current raster position z coordinate and texture coordinates to each pixel, then assigning x and y window coordinates to the nth fragment such that

x_n=x_r+n%widthy_n=y_r+ân/width,â

GL_RED

Each pixel is a single red component. This component is converted to the internal floating-point format in the same way the red component of an RGBA pixel is. It is then converted to an RGBA pixel with green and blue set to 0, and alpha set to 1. After this conversion, the pixel is treated as if it had been read as an RGBA pixel.

GL_GREEN

Each pixel is a single green component. This component is converted to the internal floating-point format in the same way the green component of an RGBA pixel is. It is then converted to an RGBA pixel with red and blue set to 0, and alpha set to 1. After this conversion, the pixel is treated as if it had been read as an RGBA pixel.

GL_BLUE

Each pixel is a single blue component. This component is converted to the internal floating-point format in the same way the blue component of an RGBA pixel is. It is then converted to an RGBA pixel with red and green set to 0, and alpha set to 1. After this conversion, the pixel is treated as if it had been read as an RGBA pixel.

GL_ALPHA

Each pixel is a single alpha component. This component is converted to the internal floating-point format in the same way the alpha component of an RGBA pixel is. It is then converted to an RGBA pixel with red, green, and blue set to 0. After this conversion, the pixel is treated as if it had been read as an RGBA pixel.

GL_RGB

GL_BGR

Each pixel is a three-component group: red first, followed by green, followed by blue; for GL_BGR, the first component is blue, followed by green and then red. Each component is converted to the internal floating-point format in the same way the red, green, and blue components of an RGBA pixel are. The color triple is converted to an RGBA pixel with alpha set to 1. After this conversion, the pixel is treated as if it had been read as an RGBA pixel.

GL_LUMINANCE

Each pixel is a single luminance component. This component is converted to the internal floating-point format in the same way the red component of an RGBA pixel is. It is then converted to an RGBA pixel with red, green, and blue set to the converted luminance value, and alpha set to 1. After this conversion, the pixel is treated as if it had been read as an RGBA pixel.

GL_LUMINANCE_ALPHA

Each pixel is a two-component group: luminance first, followed by alpha. The two components are converted to the internal floating-point format in the same way the red component of an RGBA pixel is. They are then converted to an RGBA pixel with red, green, and blue set to the converted luminance value, and alpha set to the converted alpha value. After this conversion, the pixel is treated as if it had been read as an RGBA pixel.

The following table summarizes the meaning of the valid constants for the type parameter:

Type: Corresponding Type
GL_UNSIGNED_BYTE: unsigned 8-bit integer
GL_BYTE: signed 8-bit integer
GL_BITMAP: single bits in unsigned 8-bit integers
GL_UNSIGNED_SHORT: unsigned 16-bit integer
GL_SHORT: signed 16-bit integer
GL_UNSIGNED_INT: unsigned 32-bit integer
GL_INT: 32-bit integer
GL_FLOAT: single-precision floating-point
GL_UNSIGNED_BYTE_3_3_2: unsigned 8-bit integer
GL_UNSIGNED_BYTE_2_3_3_REV: unsigned 8-bit integer with reversed component ordering
GL_UNSIGNED_SHORT_5_6_5: unsigned 16-bit integer
GL_UNSIGNED_SHORT_5_6_5_REV: unsigned 16-bit integer with reversed component ordering
GL_UNSIGNED_SHORT_4_4_4_4: unsigned 16-bit integer
GL_UNSIGNED_SHORT_4_4_4_4_REV: unsigned 16-bit integer with reversed component ordering
GL_UNSIGNED_SHORT_5_5_5_1: unsigned 16-bit integer
GL_UNSIGNED_SHORT_1_5_5_5_REV: unsigned 16-bit integer with reversed component ordering
GL_UNSIGNED_INT_8_8_8_8: unsigned 32-bit integer
GL_UNSIGNED_INT_8_8_8_8_REV: unsigned 32-bit integer with reversed component ordering
GL_UNSIGNED_INT_10_10_10_2: unsigned 32-bit integer
GL_UNSIGNED_INT_2_10_10_10_REV: unsigned 32-bit integer with reversed component ordering

The rasterization described so far assumes pixel zoom factors of 1. If glPixelZoom is used to change the x and y pixel zoom factors, pixels are converted to fragments as follows. If (x_r,y_r) is the current raster position, and a given pixel is in the nth column and mth row of the pixel rectangle, then fragments are generated for pixels whose centers are in the rectangle with corners at

(x_r+zoom_x,â¢n,y_r+zoom_y,â¢m)(x_r+zoom_x,â¡(n+1,),y_r+zoom_y,â¡(m+1,))

where zoom_x is the value of GL_ZOOM_X and zoom_y is the value of GL_ZOOM_Y.

GL_INVALID_ENUM is generated if format or type is not one of the accepted values.

GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not either GL_COLOR_INDEX or GL_STENCIL_INDEX.

GL_INVALID_VALUE is generated if either width or height is negative.

GL_INVALID_OPERATION is generated if format is GL_STENCIL_INDEX and there is no stencil buffer.

GL_INVALID_OPERATION is generated if format is GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_BGR, GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA, and the GL is in color index mode.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glDrawPixels is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glDrawRangeElements mode start end count type indices

Render primitives from array data.

mode: Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES, GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
start: Specifies the minimum array index contained in indices.
end: Specifies the maximum array index contained in indices.
count: Specifies the number of elements to be rendered.
type: Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.
indices: Specifies a pointer to the location where the indices are stored.

glDrawRangeElements is a restricted form of glDrawElements. mode, start, end, and count match the corresponding arguments to glDrawElements, with the additional constraint that all values in the arrays count must lie between start and end, inclusive.

Implementations denote recommended maximum amounts of vertex and index data, which may be queried by calling glGet with argument GL_MAX_ELEMENTS_VERTICES and GL_MAX_ELEMENTS_INDICES. If end-start+1 is greater than the value of GL_MAX_ELEMENTS_VERTICES, or if count is greater than the value of GL_MAX_ELEMENTS_INDICES, then the call may operate at reduced performance. There is no requirement that all vertices in the range [start,end] be referenced. However, the implementation may partially process unused vertices, reducing performance from what could be achieved with an optimal index set.

When glDrawRangeElements is called, it uses count sequential elements from an enabled array, starting at start to construct a sequence of geometric primitives. mode specifies what kind of primitives are constructed, and how the array elements construct these primitives. If more than one array is enabled, each is used. If GL_VERTEX_ARRAY is not enabled, no geometric primitives are constructed.

Vertex attributes that are modified by glDrawRangeElements have an unspecified value after glDrawRangeElements returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current color is undefined after glDrawRangeElements executes. Attributes that aren’t modified maintain their previous values.

It is an error for indices to lie outside the range [start,end], but implementations may not check for this situation. Such indices cause implementation-dependent behavior.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_VALUE is generated if count is negative.

GL_INVALID_VALUE is generated if end<start.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array or the element array and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glDrawRangeElements is executed between the execution of glBegin and the corresponding glEnd.

Function: void glEdgeFlagPointer stride pointer

Define an array of edge flags.

stride: Specifies the byte offset between consecutive edge flags. If stride is 0, the edge flags are understood to be tightly packed in the array. The initial value is 0.
pointer: Specifies a pointer to the first edge flag in the array. The initial value is 0.

glEdgeFlagPointer specifies the location and data format of an array of boolean edge flags to use when rendering. stride specifies the byte stride from one edge flag to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays.

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer) while an edge flag array is specified, pointer is treated as a byte offset into the buffer object’s data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as edge flag vertex array client-side state (GL_EDGE_FLAG_ARRAY_BUFFER_BINDING).

When an edge flag array is specified, stride and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable the edge flag array, call glEnableClientState and glDisableClientState with the argument GL_EDGE_FLAG_ARRAY. If enabled, the edge flag array is used when glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, glDrawRangeElements, or glArrayElement is called.

GL_INVALID_ENUM is generated if stride is negative.

Function: void glEdgeFlag flag

Function: void glEdgeFlagv flag

Flag edges as either boundary or nonboundary.

flag: Specifies the current edge flag value, either GL_TRUE or GL_FALSE. The initial value is GL_TRUE.

Each vertex of a polygon, separate triangle, or separate quadrilateral specified between a glBegin/glEnd pair is marked as the start of either a boundary or nonboundary edge. If the current edge flag is true when the vertex is specified, the vertex is marked as the start of a boundary edge. Otherwise, the vertex is marked as the start of a nonboundary edge. glEdgeFlag sets the edge flag bit to GL_TRUE if flag is GL_TRUE and to GL_FALSE otherwise.

The vertices of connected triangles and connected quadrilaterals are always marked as boundary, regardless of the value of the edge flag.

Boundary and nonboundary edge flags on vertices are significant only if GL_POLYGON_MODE is set to GL_POINT or GL_LINE. See glPolygonMode.

Function: void glEnableClientState cap

Function: void glDisableClientState cap

Enable or disable client-side capability.

cap: Specifies the capability to enable. Symbolic constants GL_COLOR_ARRAY, GL_EDGE_FLAG_ARRAY, GL_FOG_COORD_ARRAY, GL_INDEX_ARRAY, GL_NORMAL_ARRAY, GL_SECONDARY_COLOR_ARRAY, GL_TEXTURE_COORD_ARRAY, and GL_VERTEX_ARRAY are accepted.

glEnableClientState and glDisableClientState enable or disable individual client-side capabilities. By default, all client-side capabilities are disabled. Both glEnableClientState and glDisableClientState take a single argument, cap, which can assume one of the following values:

GL_COLOR_ARRAY: If enabled, the color array is enabled for writing and used during rendering when glArrayElement, glDrawArrays, glDrawElements, glDrawRangeElementsglMultiDrawArrays, or glMultiDrawElements is called. See glColorPointer.
GL_EDGE_FLAG_ARRAY: If enabled, the edge flag array is enabled for writing and used during rendering when glArrayElement, glDrawArrays, glDrawElements, glDrawRangeElementsglMultiDrawArrays, or glMultiDrawElements is called. See glEdgeFlagPointer.
GL_FOG_COORD_ARRAY: If enabled, the fog coordinate array is enabled for writing and used during rendering when glArrayElement, glDrawArrays, glDrawElements, glDrawRangeElementsglMultiDrawArrays, or glMultiDrawElements is called. See glFogCoordPointer.
GL_INDEX_ARRAY: If enabled, the index array is enabled for writing and used during rendering when glArrayElement, glDrawArrays, glDrawElements, glDrawRangeElementsglMultiDrawArrays, or glMultiDrawElements is called. See glIndexPointer.
GL_NORMAL_ARRAY: If enabled, the normal array is enabled for writing and used during rendering when glArrayElement, glDrawArrays, glDrawElements, glDrawRangeElementsglMultiDrawArrays, or glMultiDrawElements is called. See glNormalPointer.
GL_SECONDARY_COLOR_ARRAY: If enabled, the secondary color array is enabled for writing and used during rendering when glArrayElement, glDrawArrays, glDrawElements, glDrawRangeElementsglMultiDrawArrays, or glMultiDrawElements is called. See glColorPointer.
GL_TEXTURE_COORD_ARRAY: If enabled, the texture coordinate array is enabled for writing and used during rendering when glArrayElement, glDrawArrays, glDrawElements, glDrawRangeElementsglMultiDrawArrays, or glMultiDrawElements is called. See glTexCoordPointer.
GL_VERTEX_ARRAY: If enabled, the vertex array is enabled for writing and used during rendering when glArrayElement, glDrawArrays, glDrawElements, glDrawRangeElementsglMultiDrawArrays, or glMultiDrawElements is called. See glVertexPointer.

GL_INVALID_ENUM is generated if cap is not an accepted value.

glEnableClientState is not allowed between the execution of glBegin and the corresponding glEnd, but an error may or may not be generated. If no error is generated, the behavior is undefined.

Function: void glEnableVertexAttribArray index

Function: void glDisableVertexAttribArray index

Enable or disable a generic vertex attribute array.

index: Specifies the index of the generic vertex attribute to be enabled or disabled.

glEnableVertexAttribArray enables the generic vertex attribute array specified by index. glDisableVertexAttribArray disables the generic vertex attribute array specified by index. By default, all client-side capabilities are disabled, including all generic vertex attribute arrays. If enabled, the values in the generic vertex attribute array will be accessed and used for rendering when calls are made to vertex array commands such as glDrawArrays, glDrawElements, glDrawRangeElements, glArrayElement, glMultiDrawElements, or glMultiDrawArrays.

GL_INVALID_VALUE is generated if index is greater than or equal to GL_MAX_VERTEX_ATTRIBS.

GL_INVALID_OPERATION is generated if either glEnableVertexAttribArray or glDisableVertexAttribArray is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glEnable cap

Function: void glDisable cap

Enable or disable server-side GL capabilities.

cap: Specifies a symbolic constant indicating a GL capability.

glEnable and glDisable enable and disable various capabilities. Use glIsEnabled or glGet to determine the current setting of any capability. The initial value for each capability with the exception of GL_DITHER and GL_MULTISAMPLE is GL_FALSE. The initial value for GL_DITHER and GL_MULTISAMPLE is GL_TRUE.

Both glEnable and glDisable take a single argument, cap, which can assume one of the following values:

GL_ALPHA_TEST: If enabled, do alpha testing. See glAlphaFunc.
GL_AUTO_NORMAL: If enabled, generate normal vectors when either GL_MAP2_VERTEX_3 or GL_MAP2_VERTEX_4 is used to generate vertices. See glMap2.
GL_BLEND: If enabled, blend the computed fragment color values with the values in the color buffers. See glBlendFunc.
GL_CLIP_PLANEi: If enabled, clip geometry against user-defined clipping plane i. See glClipPlane.
GL_COLOR_LOGIC_OP: If enabled, apply the currently selected logical operation to the computed fragment color and color buffer values. See glLogicOp.
GL_COLOR_MATERIAL: If enabled, have one or more material parameters track the current color. See glColorMaterial.
GL_COLOR_SUM: If enabled and no fragment shader is active, add the secondary color value to the computed fragment color. See glSecondaryColor.
GL_COLOR_TABLE: If enabled, perform a color table lookup on the incoming RGBA color values. See glColorTable.
GL_CONVOLUTION_1D: If enabled, perform a 1D convolution operation on incoming RGBA color values. See glConvolutionFilter1D.
GL_CONVOLUTION_2D: If enabled, perform a 2D convolution operation on incoming RGBA color values. See glConvolutionFilter2D.
GL_CULL_FACE: If enabled, cull polygons based on their winding in window coordinates. See glCullFace.
GL_DEPTH_TEST: If enabled, do depth comparisons and update the depth buffer. Note that even if the depth buffer exists and the depth mask is non-zero, the depth buffer is not updated if the depth test is disabled. See glDepthFunc and glDepthRange.
GL_DITHER: If enabled, dither color components or indices before they are written to the color buffer.
GL_FOG: If enabled and no fragment shader is active, blend a fog color into the post-texturing color. See glFog.
GL_HISTOGRAM: If enabled, histogram incoming RGBA color values. See glHistogram.
GL_INDEX_LOGIC_OP: If enabled, apply the currently selected logical operation to the incoming index and color buffer indices. See glLogicOp.
GL_LIGHTi: If enabled, include light i in the evaluation of the lighting equation. See glLightModel and glLight.
GL_LIGHTING: If enabled and no vertex shader is active, use the current lighting parameters to compute the vertex color or index. Otherwise, simply associate the current color or index with each vertex. See glMaterial, glLightModel, and glLight.
GL_LINE_SMOOTH: If enabled, draw lines with correct filtering. Otherwise, draw aliased lines. See glLineWidth.
GL_LINE_STIPPLE: If enabled, use the current line stipple pattern when drawing lines. See glLineStipple.
GL_MAP1_COLOR_4: If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate RGBA values. See glMap1.
GL_MAP1_INDEX: If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate color indices. See glMap1.
GL_MAP1_NORMAL: If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate normals. See glMap1.
GL_MAP1_TEXTURE_COORD_1: If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate s texture coordinates. See glMap1.
GL_MAP1_TEXTURE_COORD_2: If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate s and t texture coordinates. See glMap1.
GL_MAP1_TEXTURE_COORD_3: If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate s, t, and r texture coordinates. See glMap1.
GL_MAP1_TEXTURE_COORD_4: If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate s, t, r, and q texture coordinates. See glMap1.
GL_MAP1_VERTEX_3: If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate x, y, and z vertex coordinates. See glMap1.
GL_MAP1_VERTEX_4: If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate homogeneous x, y, z, and w vertex coordinates. See glMap1.
GL_MAP2_COLOR_4: If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate RGBA values. See glMap2.
GL_MAP2_INDEX: If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate color indices. See glMap2.
GL_MAP2_NORMAL: If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate normals. See glMap2.
GL_MAP2_TEXTURE_COORD_1: If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate s texture coordinates. See glMap2.
GL_MAP2_TEXTURE_COORD_2: If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate s and t texture coordinates. See glMap2.
GL_MAP2_TEXTURE_COORD_3: If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate s, t, and r texture coordinates. See glMap2.
GL_MAP2_TEXTURE_COORD_4: If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate s, t, r, and q texture coordinates. See glMap2.
GL_MAP2_VERTEX_3: If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate x, y, and z vertex coordinates. See glMap2.
GL_MAP2_VERTEX_4: If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate homogeneous x, y, z, and w vertex coordinates. See glMap2.
GL_MINMAX: If enabled, compute the minimum and maximum values of incoming RGBA color values. See glMinmax.
GL_MULTISAMPLE: If enabled, use multiple fragment samples in computing the final color of a pixel. See glSampleCoverage.
GL_NORMALIZE: If enabled and no vertex shader is active, normal vectors are normalized to unit length after transformation and before lighting. This method is generally less efficient than GL_RESCALE_NORMAL. See glNormal and glNormalPointer.
GL_POINT_SMOOTH: If enabled, draw points with proper filtering. Otherwise, draw aliased points. See glPointSize.
GL_POINT_SPRITE: If enabled, calculate texture coordinates for points based on texture environment and point parameter settings. Otherwise texture coordinates are constant across points.
GL_POLYGON_OFFSET_FILL: If enabled, and if the polygon is rendered in GL_FILL mode, an offset is added to depth values of a polygon’s fragments before the depth comparison is performed. See glPolygonOffset.
GL_POLYGON_OFFSET_LINE: If enabled, and if the polygon is rendered in GL_LINE mode, an offset is added to depth values of a polygon’s fragments before the depth comparison is performed. See glPolygonOffset.
GL_POLYGON_OFFSET_POINT: If enabled, an offset is added to depth values of a polygon’s fragments before the depth comparison is performed, if the polygon is rendered in GL_POINT mode. See glPolygonOffset.
GL_POLYGON_SMOOTH: If enabled, draw polygons with proper filtering. Otherwise, draw aliased polygons. For correct antialiased polygons, an alpha buffer is needed and the polygons must be sorted front to back.
GL_POLYGON_STIPPLE: If enabled, use the current polygon stipple pattern when rendering polygons. See glPolygonStipple.
GL_POST_COLOR_MATRIX_COLOR_TABLE: If enabled, perform a color table lookup on RGBA color values after color matrix transformation. See glColorTable.
GL_POST_CONVOLUTION_COLOR_TABLE: If enabled, perform a color table lookup on RGBA color values after convolution. See glColorTable.
GL_RESCALE_NORMAL: If enabled and no vertex shader is active, normal vectors are scaled after transformation and before lighting by a factor computed from the modelview matrix. If the modelview matrix scales space uniformly, this has the effect of restoring the transformed normal to unit length. This method is generally more efficient than GL_NORMALIZE. See glNormal and glNormalPointer.
GL_SAMPLE_ALPHA_TO_COVERAGE: If enabled, compute a temporary coverage value where each bit is determined by the alpha value at the corresponding sample location. The temporary coverage value is then ANDed with the fragment coverage value.
GL_SAMPLE_ALPHA_TO_ONE: If enabled, each sample alpha value is replaced by the maximum representable alpha value.
GL_SAMPLE_COVERAGE: If enabled, the fragment’s coverage is ANDed with the temporary coverage value. If GL_SAMPLE_COVERAGE_INVERT is set to GL_TRUE, invert the coverage value. See glSampleCoverage.
GL_SEPARABLE_2D: If enabled, perform a two-dimensional convolution operation using a separable convolution filter on incoming RGBA color values. See glSeparableFilter2D.
GL_SCISSOR_TEST: If enabled, discard fragments that are outside the scissor rectangle. See glScissor.
GL_STENCIL_TEST: If enabled, do stencil testing and update the stencil buffer. See glStencilFunc and glStencilOp.
GL_TEXTURE_1D: If enabled and no fragment shader is active, one-dimensional texturing is performed (unless two- or three-dimensional or cube-mapped texturing is also enabled). See glTexImage1D.
GL_TEXTURE_2D: If enabled and no fragment shader is active, two-dimensional texturing is performed (unless three-dimensional or cube-mapped texturing is also enabled). See glTexImage2D.
GL_TEXTURE_3D: If enabled and no fragment shader is active, three-dimensional texturing is performed (unless cube-mapped texturing is also enabled). See glTexImage3D.
GL_TEXTURE_CUBE_MAP: If enabled and no fragment shader is active, cube-mapped texturing is performed. See glTexImage2D.
GL_TEXTURE_GEN_Q: If enabled and no vertex shader is active, the q texture coordinate is computed using the texture generation function defined with glTexGen. Otherwise, the current q texture coordinate is used. See glTexGen.
GL_TEXTURE_GEN_R: If enabled and no vertex shader is active, the r texture coordinate is computed using the texture generation function defined with glTexGen. Otherwise, the current r texture coordinate is used. See glTexGen.
GL_TEXTURE_GEN_S: If enabled and no vertex shader is active, the s texture coordinate is computed using the texture generation function defined with glTexGen. Otherwise, the current s texture coordinate is used. See glTexGen.
GL_TEXTURE_GEN_T: If enabled and no vertex shader is active, the t texture coordinate is computed using the texture generation function defined with glTexGen. Otherwise, the current t texture coordinate is used. See glTexGen.
GL_VERTEX_PROGRAM_POINT_SIZE: If enabled and a vertex shader is active, then the derived point size is taken from the (potentially clipped) shader builtin gl_PointSize and clamped to the implementation-dependent point size range.
GL_VERTEX_PROGRAM_TWO_SIDE: If enabled and a vertex shader is active, it specifies that the GL will choose between front and back colors based on the polygon’s face direction of which the vertex being shaded is a part. It has no effect on points or lines.

GL_INVALID_ENUM is generated if cap is not one of the values listed previously.

GL_INVALID_OPERATION is generated if glEnable or glDisable is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glEvalCoord1f u

Function: void glEvalCoord1d u

Function: void glEvalCoord2f u v

Function: void glEvalCoord2d u v

Function: void glEvalCoord1fv u

Function: void glEvalCoord1dv u

Function: void glEvalCoord2fv u

Function: void glEvalCoord2dv u

Evaluate enabled one- and two-dimensional maps.

u: Specifies a value that is the domain coordinate u to the basis function defined in a previous glMap1 or glMap2 command.
v: Specifies a value that is the domain coordinate v to the basis function defined in a previous glMap2 command. This argument is not present in a glEvalCoord1 command.

glEvalCoord1 evaluates enabled one-dimensional maps at argument u. glEvalCoord2 does the same for two-dimensional maps using two domain values, u and v. To define a map, call glMap1 and glMap2; to enable and disable it, call glEnable and glDisable.

When one of the glEvalCoord commands is issued, all currently enabled maps of the indicated dimension are evaluated. Then, for each enabled map, it is as if the corresponding GL command had been issued with the computed value. That is, if GL_MAP1_INDEX or GL_MAP2_INDEX is enabled, a glIndex command is simulated. If GL_MAP1_COLOR_4 or GL_MAP2_COLOR_4 is enabled, a glColor command is simulated. If GL_MAP1_NORMAL or GL_MAP2_NORMAL is enabled, a normal vector is produced, and if any of GL_MAP1_TEXTURE_COORD_1, GL_MAP1_TEXTURE_COORD_2, GL_MAP1_TEXTURE_COORD_3, GL_MAP1_TEXTURE_COORD_4, GL_MAP2_TEXTURE_COORD_1, GL_MAP2_TEXTURE_COORD_2, GL_MAP2_TEXTURE_COORD_3, or GL_MAP2_TEXTURE_COORD_4 is enabled, then an appropriate glTexCoord command is simulated.

For color, color index, normal, and texture coordinates the GL uses evaluated values instead of current values for those evaluations that are enabled, and current values otherwise, However, the evaluated values do not update the current values. Thus, if glVertex commands are interspersed with glEvalCoord commands, the color, normal, and texture coordinates associated with the glVertex commands are not affected by the values generated by the glEvalCoord commands, but only by the most recent glColor, glIndex, glNormal, and glTexCoord commands.

No commands are issued for maps that are not enabled. If more than one texture evaluation is enabled for a particular dimension (for example, GL_MAP2_TEXTURE_COORD_1 and GL_MAP2_TEXTURE_COORD_2), then only the evaluation of the map that produces the larger number of coordinates (in this case, GL_MAP2_TEXTURE_COORD_2) is carried out. GL_MAP1_VERTEX_4 overrides GL_MAP1_VERTEX_3, and GL_MAP2_VERTEX_4 overrides GL_MAP2_VERTEX_3, in the same manner. If neither a three- nor a four-component vertex map is enabled for the specified dimension, the glEvalCoord command is ignored.

If you have enabled automatic normal generation, by calling glEnable with argument GL_AUTO_NORMAL, glEvalCoord2 generates surface normals analytically, regardless of the contents or enabling of the GL_MAP2_NORMAL map. Let

m=âp,/âu,,Ãâp,/âv,,

Then the generated normal n is n=m/â¥m,â¥,

If automatic normal generation is disabled, the corresponding normal map GL_MAP2_NORMAL, if enabled, is used to produce a normal. If neither automatic normal generation nor a normal map is enabled, no normal is generated for glEvalCoord2 commands.

Function: void glEvalMesh1 mode i1 i2

Function: void glEvalMesh2 mode i1 i2 j1 j2

Compute a one- or two-dimensional grid of points or lines.

mode: In glEvalMesh1, specifies whether to compute a one-dimensional mesh of points or lines. Symbolic constants GL_POINT and GL_LINE are accepted.
i1
i2: Specify the first and last integer values for grid domain variable i.

glMapGrid and glEvalMesh are used in tandem to efficiently generate and evaluate a series of evenly-spaced map domain values. glEvalMesh steps through the integer domain of a one- or two-dimensional grid, whose range is the domain of the evaluation maps specified by glMap1 and glMap2. mode determines whether the resulting vertices are connected as points, lines, or filled polygons.

In the one-dimensional case, glEvalMesh1, the mesh is generated as if the following code fragment were executed:

where

glBegin( type );
for ( i = i1; i <= i2; i += 1 )
   glEvalCoord1( iÂ·Îu+u_1 );
glEnd();

Îu=(u_2-u_1,)/n

and n, u_1, and u_2 are the arguments to the most recent glMapGrid1 command. type is GL_POINTS if mode is GL_POINT, or GL_LINES if mode is GL_LINE.

The one absolute numeric requirement is that if i=n, then the value computed from iÂ·Îu+u_1 is exactly u_2.

In the two-dimensional case, glEvalMesh2, let .cp Îu=(u_2-u_1,)/n

Îv=(v_2-v_1,)/m

where n, u_1, u_2, m, v_1, and v_2 are the arguments to the most recent glMapGrid2 command. Then, if mode is GL_FILL, the glEvalMesh2 command is equivalent to:

for ( j = j1; j < j2; j += 1 ) {
   glBegin( GL_QUAD_STRIP );
   for ( i = i1; i <= i2; i += 1 ) {
      glEvalCoord2( iÂ·Îu+u_1,jÂ·Îv+v_1 );
      glEvalCoord2( iÂ·Îu+u_1,(j+1,)Â·Îv+v_1 );
   }
   glEnd();
}

If mode is GL_LINE, then a call to glEvalMesh2 is equivalent to:

for ( j = j1; j <= j2; j += 1 ) {
   glBegin( GL_LINE_STRIP );
   for ( i = i1; i <= i2; i += 1 )
      glEvalCoord2( iÂ·Îu+u_1,jÂ·Îv+v_1 );
   glEnd();
}

for ( i = i1;  i <= i2; i += 1 ) {
   glBegin( GL_LINE_STRIP );
   for ( j = j1; j <= j1; j += 1 )
      glEvalCoord2( iÂ·Îu+u_1,jÂ·Îv+v_1 );
   glEnd();
}

And finally, if mode is GL_POINT, then a call to glEvalMesh2 is equivalent to:

glBegin( GL_POINTS );
for ( j = j1; j <= j2; j += 1 )
   for ( i = i1; i <= i2; i += 1 )
      glEvalCoord2( iÂ·Îu+u_1,jÂ·Îv+v_1 );
glEnd();

In all three cases, the only absolute numeric requirements are that if i=n, then the value computed from iÂ·Îu+u_1 is exactly u_2, and if j=m, then the value computed from jÂ·Îv+v_1 is exactly v_2.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_OPERATION is generated if glEvalMesh is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glEvalPoint1 i

Function: void glEvalPoint2 i j

Generate and evaluate a single point in a mesh.

i: Specifies the integer value for grid domain variable i.
j: Specifies the integer value for grid domain variable j (glEvalPoint2 only).

glMapGrid and glEvalMesh are used in tandem to efficiently generate and evaluate a series of evenly spaced map domain values. glEvalPoint can be used to evaluate a single grid point in the same gridspace that is traversed by glEvalMesh. Calling glEvalPoint1 is equivalent to calling where Îu=(u_2-u_1,)/n

glEvalCoord1( iÂ·Îu+u_1 );

and n, u_1, and u_2 are the arguments to the most recent glMapGrid1 command. The one absolute numeric requirement is that if i=n, then the value computed from iÂ·Îu+u_1 is exactly u_2.

In the two-dimensional case, glEvalPoint2, let

Îu=(u_2-u_1,)/nÎv=(v_2-v_1,)/m

where n, u_1, u_2, m, v_1, and v_2 are the arguments to the most recent glMapGrid2 command. Then the glEvalPoint2 command is equivalent to calling The only absolute numeric requirements are that if i=n, then the value computed from iÂ·Îu+u_1 is exactly u_2, and if j=m, then the value computed from jÂ·Îv+v_1 is exactly v_2.

glEvalCoord2( iÂ·Îu+u_1,jÂ·Îv+v_1 );

Function: void glFeedbackBuffer size type buffer

Controls feedback mode.

size: Specifies the maximum number of values that can be written into buffer.
type: Specifies a symbolic constant that describes the information that will be returned for each vertex. GL_2D, GL_3D, GL_3D_COLOR, GL_3D_COLOR_TEXTURE, and GL_4D_COLOR_TEXTURE are accepted.
buffer: Returns the feedback data.

The glFeedbackBuffer function controls feedback. Feedback, like selection, is a GL mode. The mode is selected by calling glRenderMode with GL_FEEDBACK. When the GL is in feedback mode, no pixels are produced by rasterization. Instead, information about primitives that would have been rasterized is fed back to the application using the GL.

glFeedbackBuffer has three arguments: buffer is a pointer to an array of floating-point values into which feedback information is placed. size indicates the size of the array. type is a symbolic constant describing the information that is fed back for each vertex. glFeedbackBuffer must be issued before feedback mode is enabled (by calling glRenderMode with argument GL_FEEDBACK). Setting GL_FEEDBACK without establishing the feedback buffer, or calling glFeedbackBuffer while the GL is in feedback mode, is an error.

When glRenderMode is called while in feedback mode, it returns the number of entries placed in the feedback array and resets the feedback array pointer to the base of the feedback buffer. The returned value never exceeds size. If the feedback data required more room than was available in buffer, glRenderMode returns a negative value. To take the GL out of feedback mode, call glRenderMode with a parameter value other than GL_FEEDBACK.

While in feedback mode, each primitive, bitmap, or pixel rectangle that would be rasterized generates a block of values that are copied into the feedback array. If doing so would cause the number of entries to exceed the maximum, the block is partially written so as to fill the array (if there is any room left at all), and an overflow flag is set. Each block begins with a code indicating the primitive type, followed by values that describe the primitive’s vertices and associated data. Entries are also written for bitmaps and pixel rectangles. Feedback occurs after polygon culling and glPolygonMode interpretation of polygons has taken place, so polygons that are culled are not returned in the feedback buffer. It can also occur after polygons with more than three edges are broken up into triangles, if the GL implementation renders polygons by performing this decomposition.

The glPassThrough command can be used to insert a marker into the feedback buffer. See glPassThrough.

Following is the grammar for the blocks of values written into the feedback buffer. Each primitive is indicated with a unique identifying value followed by some number of vertices. Polygon entries include an integer value indicating how many vertices follow. A vertex is fed back as some number of floating-point values, as determined by type. Colors are fed back as four values in RGBA mode and one value in color index mode.

feedbackList â feedbackItem feedbackList | feedbackItem feedbackItem â point | lineSegment | polygon | bitmap | pixelRectangle | passThru point âGL_POINT_TOKEN vertex lineSegment âGL_LINE_TOKEN vertex vertex | GL_LINE_RESET_TOKEN vertex vertex polygon âGL_POLYGON_TOKEN n polySpec polySpec â polySpec vertex | vertex vertex vertex bitmap âGL_BITMAP_TOKEN vertex pixelRectangle âGL_DRAW_PIXEL_TOKEN vertex | GL_COPY_PIXEL_TOKEN vertex passThru âGL_PASS_THROUGH_TOKEN value vertex â 2d | 3d | 3dColor | 3dColorTexture | 4dColorTexture 2d â value value 3d â value value value 3dColor â value value value color 3dColorTexture â value value value color tex 4dColorTexture â value value value value color tex color â rgba | index rgba â value value value value index â value tex â value value value value

value is a floating-point number, and n is a floating-point integer giving the number of vertices in the polygon. GL_POINT_TOKEN, GL_LINE_TOKEN, GL_LINE_RESET_TOKEN, GL_POLYGON_TOKEN, GL_BITMAP_TOKEN, GL_DRAW_PIXEL_TOKEN, GL_COPY_PIXEL_TOKEN and GL_PASS_THROUGH_TOKEN are symbolic floating-point constants. GL_LINE_RESET_TOKEN is returned whenever the line stipple pattern is reset. The data returned as a vertex depends on the feedback type.

The following table gives the correspondence between type and the number of values per vertex. k is 1 in color index mode and 4 in RGBA mode.

Type: Coordinates, Color, Texture, Total Number of Values
GL_2D: x, y, , , 2
GL_3D: x, y, z, , , 3
GL_3D_COLOR: x, y, z, k, , 3+k
GL_3D_COLOR_TEXTURE: x, y, z, k, 4 , 7+k
GL_4D_COLOR_TEXTURE: x, y, z, w, k, 4 , 8+k

Feedback vertex coordinates are in window coordinates, except w, which is in clip coordinates. Feedback colors are lighted, if lighting is enabled. Feedback texture coordinates are generated, if texture coordinate generation is enabled. They are always transformed by the texture matrix.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if size is negative.

GL_INVALID_OPERATION is generated if glFeedbackBuffer is called while the render mode is GL_FEEDBACK, or if glRenderMode is called with argument GL_FEEDBACK before glFeedbackBuffer is called at least once.

GL_INVALID_OPERATION is generated if glFeedbackBuffer is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glFinish

Block until all GL execution is complete.

glFinish does not return until the effects of all previously called GL commands are complete. Such effects include all changes to GL state, all changes to connection state, and all changes to the frame buffer contents.

GL_INVALID_OPERATION is generated if glFinish is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glFlush

Force execution of GL commands in finite time.

Different GL implementations buffer commands in several different locations, including network buffers and the graphics accelerator itself. glFlush empties all of these buffers, causing all issued commands to be executed as quickly as they are accepted by the actual rendering engine. Though this execution may not be completed in any particular time period, it does complete in finite time.

Because any GL program might be executed over a network, or on an accelerator that buffers commands, all programs should call glFlush whenever they count on having all of their previously issued commands completed. For example, call glFlush before waiting for user input that depends on the generated image.

GL_INVALID_OPERATION is generated if glFlush is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glFogCoordPointer type stride pointer

Define an array of fog coordinates.

type: Specifies the data type of each fog coordinate. Symbolic constants GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
stride: Specifies the byte offset between consecutive fog coordinates. If stride is 0, the array elements are understood to be tightly packed. The initial value is 0.
pointer: Specifies a pointer to the first coordinate of the first fog coordinate in the array. The initial value is 0.

glFogCoordPointer specifies the location and data format of an array of fog coordinates to use when rendering. type specifies the data type of each fog coordinate, and stride specifies the byte stride from one fog coordinate to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays.

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer) while a fog coordinate array is specified, pointer is treated as a byte offset into the buffer object’s data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as fog coordinate vertex array client-side state (GL_FOG_COORD_ARRAY_BUFFER_BINDING).

When a fog coordinate array is specified, type, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable the fog coordinate array, call glEnableClientState and glDisableClientState with the argument GL_FOG_COORD_ARRAY. If enabled, the fog coordinate array is used when glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, glDrawRangeElements, or glArrayElement is called.

GL_INVALID_ENUM is generated if type is not either GL_FLOAT or GL_DOUBLE.

GL_INVALID_VALUE is generated if stride is negative.

Function: void glFogCoordd coord

Function: void glFogCoordf coord

Function: void glFogCoorddv coord

Function: void glFogCoordfv coord

Set the current fog coordinates.

coord: Specify the fog distance.

glFogCoord specifies the fog coordinate that is associated with each vertex and the current raster position. The value specified is interpolated and used in computing the fog color (see glFog).

Function: void glFogf pname param

Function: void glFogi pname param

Function: void glFogfv pname params

Function: void glFogiv pname params

Specify fog parameters.

pname: Specifies a single-valued fog parameter. GL_FOG_MODE, GL_FOG_DENSITY, GL_FOG_START, GL_FOG_END, GL_FOG_INDEX, and GL_FOG_COORD_SRC are accepted.
param: Specifies the value that pname will be set to.

Fog is initially disabled. While enabled, fog affects rasterized geometry, bitmaps, and pixel blocks, but not buffer clear operations. To enable and disable fog, call glEnable and glDisable with argument GL_FOG.

glFog assigns the value or values in params to the fog parameter specified by pname. The following values are accepted for pname:

GL_FOG_MODE: params is a single integer or floating-point value that specifies the equation to be used to compute the fog blend factor, f. Three symbolic constants are accepted: GL_LINEAR, GL_EXP, and GL_EXP2. The equations corresponding to these symbolic constants are defined below. The initial fog mode is GL_EXP.
GL_FOG_DENSITY: params is a single integer or floating-point value that specifies density, the fog density used in both exponential fog equations. Only nonnegative densities are accepted. The initial fog density is 1.
GL_FOG_START: params is a single integer or floating-point value that specifies start, the near distance used in the linear fog equation. The initial near distance is 0.
GL_FOG_END: params is a single integer or floating-point value that specifies end, the far distance used in the linear fog equation. The initial far distance is 1.
GL_FOG_INDEX: params is a single integer or floating-point value that specifies i_f, the fog color index. The initial fog index is 0.
GL_FOG_COLOR: params contains four integer or floating-point values that specify C_f, the fog color. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. Floating-point values are mapped directly. After conversion, all color components are clamped to the range [0,1]. The initial fog color is (0, 0, 0, 0).
GL_FOG_COORD_SRC: params contains either of the following symbolic constants: GL_FOG_COORD or GL_FRAGMENT_DEPTH. GL_FOG_COORD specifies that the current fog coordinate should be used as distance value in the fog color computation. GL_FRAGMENT_DEPTH specifies that the current fragment depth should be used as distance value in the fog computation.

Fog blends a fog color with each rasterized pixel fragment’s post-texturing color using a blending factor f. Factor f is computed in one of three ways, depending on the fog mode. Let c be either the distance in eye coordinate from the origin (in the case that the GL_FOG_COORD_SRC is GL_FRAGMENT_DEPTH) or the current fog coordinate (in the case that GL_FOG_COORD_SRC is GL_FOG_COORD). The equation for GL_LINEAR fog is f=end-c,/end-start,

The equation for GL_EXP fog is f=e^-(densityÂ·c,),

The equation for GL_EXP2 fog is f=e^-(densityÂ·c,),^2

Regardless of the fog mode, f is clamped to the range [0,1] after it is computed. Then, if the GL is in RGBA color mode, the fragment’s red, green, and blue colors, represented by C_r, are replaced by

C_r,^â³=fÃC_r+(1-f,)ÃC_f

Fog does not affect a fragment’s alpha component.

In color index mode, the fragment’s color index i_r is replaced by

i_r,^â³=i_r+(1-f,)Ãi_f

GL_INVALID_ENUM is generated if pname is not an accepted value, or if pname is GL_FOG_MODE and params is not an accepted value.

GL_INVALID_VALUE is generated if pname is GL_FOG_DENSITY and params is negative.

GL_INVALID_OPERATION is generated if glFog is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glFrontFace mode

Define front- and back-facing polygons.

mode: Specifies the orientation of front-facing polygons. GL_CW and GL_CCW are accepted. The initial value is GL_CCW.

In a scene composed entirely of opaque closed surfaces, back-facing polygons are never visible. Eliminating these invisible polygons has the obvious benefit of speeding up the rendering of the image. To enable and disable elimination of back-facing polygons, call glEnable and glDisable with argument GL_CULL_FACE.

The projection of a polygon to window coordinates is said to have clockwise winding if an imaginary object following the path from its first vertex, its second vertex, and so on, to its last vertex, and finally back to its first vertex, moves in a clockwise direction about the interior of the polygon. The polygon’s winding is said to be counterclockwise if the imaginary object following the same path moves in a counterclockwise direction about the interior of the polygon. glFrontFace specifies whether polygons with clockwise winding in window coordinates, or counterclockwise winding in window coordinates, are taken to be front-facing. Passing GL_CCW to mode selects counterclockwise polygons as front-facing; GL_CW selects clockwise polygons as front-facing. By default, counterclockwise polygons are taken to be front-facing.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_OPERATION is generated if glFrontFace is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glFrustum left right bottom top nearVal farVal

Multiply the current matrix by a perspective matrix.

left
right: Specify the coordinates for the left and right vertical clipping planes.
bottom
top: Specify the coordinates for the bottom and top horizontal clipping planes.
nearVal
farVal: Specify the distances to the near and far depth clipping planes. Both distances must be positive.

glFrustum describes a perspective matrix that produces a perspective projection. The current matrix (see glMatrixMode) is multiplied by this matrix and the result replaces the current matrix, as if glMultMatrix were called with the following matrix as its argument:

[(2â¢nearVal,/right-left,, 0 A 0), (0 2â¢nearVal,/top-bottom,, B 0), (0 0 C D), (0 0 -1 0),]

A=right+left,/right-left,

B=top+bottom,/top-bottom,

C=-farVal+nearVal,/farVal-nearVal,,

D=-2â¢farValâ¢nearVal,/farVal-nearVal,,

Typically, the matrix mode is GL_PROJECTION, and (left,bottom-nearVal) and (right,top-nearVal) specify the points on the near clipping plane that are mapped to the lower left and upper right corners of the window, assuming that the eye is located at (0, 0, 0). -farVal specifies the location of the far clipping plane. Both nearVal and farVal must be positive.

Use glPushMatrix and glPopMatrix to save and restore the current matrix stack.

GL_INVALID_VALUE is generated if nearVal or farVal is not positive, or if left = right, or bottom = top, or near = far.

GL_INVALID_OPERATION is generated if glFrustum is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGenBuffers n buffers

Generate buffer object names.

n: Specifies the number of buffer object names to be generated.
buffers: Specifies an array in which the generated buffer object names are stored.

glGenBuffers returns n buffer object names in buffers. There is no guarantee that the names form a contiguous set of integers; however, it is guaranteed that none of the returned names was in use immediately before the call to glGenBuffers.

Buffer object names returned by a call to glGenBuffers are not returned by subsequent calls, unless they are first deleted with glDeleteBuffers.

No buffer objects are associated with the returned buffer object names until they are first bound by calling glBindBuffer.

GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_OPERATION is generated if glGenBuffers is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLuint glGenLists range

Generate a contiguous set of empty display lists.

range: Specifies the number of contiguous empty display lists to be generated.

glGenLists has one argument, range. It returns an integer n such that range contiguous empty display lists, named n, n+1, ..., n+range-1, are created. If range is 0, if there is no group of range contiguous names available, or if any error is generated, no display lists are generated, and 0 is returned.

GL_INVALID_VALUE is generated if range is negative.

GL_INVALID_OPERATION is generated if glGenLists is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGenQueries n ids

Generate query object names.

n: Specifies the number of query object names to be generated.
ids: Specifies an array in which the generated query object names are stored.

glGenQueries returns n query object names in ids. There is no guarantee that the names form a contiguous set of integers; however, it is guaranteed that none of the returned names was in use immediately before the call to glGenQueries.

Query object names returned by a call to glGenQueries are not returned by subsequent calls, unless they are first deleted with glDeleteQueries.

No query objects are associated with the returned query object names until they are first used by calling glBeginQuery.

GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_OPERATION is generated if glGenQueries is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGenTextures n textures

Generate texture names.

n: Specifies the number of texture names to be generated.
textures: Specifies an array in which the generated texture names are stored.

glGenTextures returns n texture names in textures. There is no guarantee that the names form a contiguous set of integers; however, it is guaranteed that none of the returned names was in use immediately before the call to glGenTextures.

The generated textures have no dimensionality; they assume the dimensionality of the texture target to which they are first bound (see glBindTexture).

Texture names returned by a call to glGenTextures are not returned by subsequent calls, unless they are first deleted with glDeleteTextures.

GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_OPERATION is generated if glGenTextures is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetActiveAttrib program index bufSize length size type name

Returns information about an active attribute variable for the specified program object.

program: Specifies the program object to be queried.
index: Specifies the index of the attribute variable to be queried.
bufSize: Specifies the maximum number of characters OpenGL is allowed to write in the character buffer indicated by name.
length: Returns the number of characters actually written by OpenGL in the string indicated by name (excluding the null terminator) if a value other than NULL is passed.
size: Returns the size of the attribute variable.
type: Returns the data type of the attribute variable.
name: Returns a null terminated string containing the name of the attribute variable.

glGetActiveAttrib returns information about an active attribute variable in the program object specified by program. The number of active attributes can be obtained by calling glGetProgram with the value GL_ACTIVE_ATTRIBUTES. A value of 0 for index selects the first active attribute variable. Permissible values for index range from 0 to the number of active attribute variables minus 1.

A vertex shader may use either built-in attribute variables, user-defined attribute variables, or both. Built-in attribute variables have a prefix of "gl_" and reference conventional OpenGL vertex attribtes (e.g., gl_Vertex, gl_Normal, etc., see the OpenGL Shading Language specification for a complete list.) User-defined attribute variables have arbitrary names and obtain their values through numbered generic vertex attributes. An attribute variable (either built-in or user-defined) is considered active if it is determined during the link operation that it may be accessed during program execution. Therefore, program should have previously been the target of a call to glLinkProgram, but it is not necessary for it to have been linked successfully.

The size of the character buffer required to store the longest attribute variable name in program can be obtained by calling glGetProgram with the value GL_ACTIVE_ATTRIBUTE_MAX_LENGTH. This value should be used to allocate a buffer of sufficient size to store the returned attribute name. The size of this character buffer is passed in bufSize, and a pointer to this character buffer is passed in name.

glGetActiveAttrib returns the name of the attribute variable indicated by index, storing it in the character buffer specified by name. The string returned will be null terminated. The actual number of characters written into this buffer is returned in length, and this count does not include the null termination character. If the length of the returned string is not required, a value of NULL can be passed in the length argument.

The type argument will return a pointer to the attribute variable’s data type. The symbolic constants GL_FLOAT, GL_FLOAT_VEC2, GL_FLOAT_VEC3, GL_FLOAT_VEC4, GL_FLOAT_MAT2, GL_FLOAT_MAT3, GL_FLOAT_MAT4, GL_FLOAT_MAT2x3, GL_FLOAT_MAT2x4, GL_FLOAT_MAT3x2, GL_FLOAT_MAT3x4, GL_FLOAT_MAT4x2, or GL_FLOAT_MAT4x3 may be returned. The size argument will return the size of the attribute, in units of the type returned in type.

The list of active attribute variables may include both built-in attribute variables (which begin with the prefix "gl_") as well as user-defined attribute variable names.

This function will return as much information as it can about the specified active attribute variable. If no information is available, length will be 0, and name will be an empty string. This situation could occur if this function is called after a link operation that failed. If an error occurs, the return values length, size, type, and name will be unmodified.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_VALUE is generated if index is greater than or equal to the number of active attribute variables in program.

GL_INVALID_OPERATION is generated if glGetActiveAttrib is executed between the execution of glBegin and the corresponding execution of glEnd.

GL_INVALID_VALUE is generated if bufSize is less than 0.

Function: void glGetActiveUniform program index bufSize length size type name

Returns information about an active uniform variable for the specified program object.

program: Specifies the program object to be queried.
index: Specifies the index of the uniform variable to be queried.
bufSize: Specifies the maximum number of characters OpenGL is allowed to write in the character buffer indicated by name.
length: Returns the number of characters actually written by OpenGL in the string indicated by name (excluding the null terminator) if a value other than NULL is passed.
size: Returns the size of the uniform variable.
type: Returns the data type of the uniform variable.
name: Returns a null terminated string containing the name of the uniform variable.

glGetActiveUniform returns information about an active uniform variable in the program object specified by program. The number of active uniform variables can be obtained by calling glGetProgram with the value GL_ACTIVE_UNIFORMS. A value of 0 for index selects the first active uniform variable. Permissible values for index range from 0 to the number of active uniform variables minus 1.

Shaders may use either built-in uniform variables, user-defined uniform variables, or both. Built-in uniform variables have a prefix of "gl_" and reference existing OpenGL state or values derived from such state (e.g., gl_Fog, gl_ModelViewMatrix, etc., see the OpenGL Shading Language specification for a complete list.) User-defined uniform variables have arbitrary names and obtain their values from the application through calls to glUniform. A uniform variable (either built-in or user-defined) is considered active if it is determined during the link operation that it may be accessed during program execution. Therefore, program should have previously been the target of a call to glLinkProgram, but it is not necessary for it to have been linked successfully.

The size of the character buffer required to store the longest uniform variable name in program can be obtained by calling glGetProgram with the value GL_ACTIVE_UNIFORM_MAX_LENGTH. This value should be used to allocate a buffer of sufficient size to store the returned uniform variable name. The size of this character buffer is passed in bufSize, and a pointer to this character buffer is passed in name.

glGetActiveUniform returns the name of the uniform variable indicated by index, storing it in the character buffer specified by name. The string returned will be null terminated. The actual number of characters written into this buffer is returned in length, and this count does not include the null termination character. If the length of the returned string is not required, a value of NULL can be passed in the length argument.

The type argument will return a pointer to the uniform variable’s data type. The symbolic constants GL_FLOAT, GL_FLOAT_VEC2, GL_FLOAT_VEC3, GL_FLOAT_VEC4, GL_INT, GL_INT_VEC2, GL_INT_VEC3, GL_INT_VEC4, GL_BOOL, GL_BOOL_VEC2, GL_BOOL_VEC3, GL_BOOL_VEC4, GL_FLOAT_MAT2, GL_FLOAT_MAT3, GL_FLOAT_MAT4, GL_FLOAT_MAT2x3, GL_FLOAT_MAT2x4, GL_FLOAT_MAT3x2, GL_FLOAT_MAT3x4, GL_FLOAT_MAT4x2, GL_FLOAT_MAT4x3, GL_SAMPLER_1D, GL_SAMPLER_2D, GL_SAMPLER_3D, GL_SAMPLER_CUBE, GL_SAMPLER_1D_SHADOW, or GL_SAMPLER_2D_SHADOW may be returned.

If one or more elements of an array are active, the name of the array is returned in name, the type is returned in type, and the size parameter returns the highest array element index used, plus one, as determined by the compiler and/or linker. Only one active uniform variable will be reported for a uniform array.

Uniform variables that are declared as structures or arrays of structures will not be returned directly by this function. Instead, each of these uniform variables will be reduced to its fundamental components containing the "." and "[]" operators such that each of the names is valid as an argument to glGetUniformLocation. Each of these reduced uniform variables is counted as one active uniform variable and is assigned an index. A valid name cannot be a structure, an array of structures, or a subcomponent of a vector or matrix.

The size of the uniform variable will be returned in size. Uniform variables other than arrays will have a size of 1. Structures and arrays of structures will be reduced as described earlier, such that each of the names returned will be a data type in the earlier list. If this reduction results in an array, the size returned will be as described for uniform arrays; otherwise, the size returned will be 1.

The list of active uniform variables may include both built-in uniform variables (which begin with the prefix "gl_") as well as user-defined uniform variable names.

This function will return as much information as it can about the specified active uniform variable. If no information is available, length will be 0, and name will be an empty string. This situation could occur if this function is called after a link operation that failed. If an error occurs, the return values length, size, type, and name will be unmodified.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_VALUE is generated if index is greater than or equal to the number of active uniform variables in program.

GL_INVALID_OPERATION is generated if glGetActiveUniform is executed between the execution of glBegin and the corresponding execution of glEnd.

GL_INVALID_VALUE is generated if bufSize is less than 0.

Function: void glGetAttachedShaders program maxCount count shaders

Returns the handles of the shader objects attached to a program object.

program: Specifies the program object to be queried.
maxCount: Specifies the size of the array for storing the returned object names.
count: Returns the number of names actually returned in objects.
shaders: Specifies an array that is used to return the names of attached shader objects.

glGetAttachedShaders returns the names of the shader objects attached to program. The names of shader objects that are attached to program will be returned in shaders. The actual number of shader names written into shaders is returned in count. If no shader objects are attached to program, count is set to 0. The maximum number of shader names that may be returned in shaders is specified by maxCount.

If the number of names actually returned is not required (for instance, if it has just been obtained by calling glGetProgram), a value of NULL may be passed for count. If no shader objects are attached to program, a value of 0 will be returned in count. The actual number of attached shaders can be obtained by calling glGetProgram with the value GL_ATTACHED_SHADERS.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_VALUE is generated if maxCount is less than 0.

GL_INVALID_OPERATION is generated if glGetAttachedShaders is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLint glGetAttribLocation program name

Returns the location of an attribute variable.

program: Specifies the program object to be queried.
name: Points to a null terminated string containing the name of the attribute variable whose location is to be queried.

glGetAttribLocation queries the previously linked program object specified by program for the attribute variable specified by name and returns the index of the generic vertex attribute that is bound to that attribute variable. If name is a matrix attribute variable, the index of the first column of the matrix is returned. If the named attribute variable is not an active attribute in the specified program object or if name starts with the reserved prefix "gl_", a value of -1 is returned.

The association between an attribute variable name and a generic attribute index can be specified at any time by calling glBindAttribLocation. Attribute bindings do not go into effect until glLinkProgram is called. After a program object has been linked successfully, the index values for attribute variables remain fixed until the next link command occurs. The attribute values can only be queried after a link if the link was successful. glGetAttribLocation returns the binding that actually went into effect the last time glLinkProgram was called for the specified program object. Attribute bindings that have been specified since the last link operation are not returned by glGetAttribLocation.

GL_INVALID_OPERATION is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_OPERATION is generated if program has not been successfully linked.

GL_INVALID_OPERATION is generated if glGetAttribLocation is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetBufferParameteriv target value data

Return parameters of a buffer object.

target: Specifies the target buffer object. The symbolic constant must be GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.
value: Specifies the symbolic name of a buffer object parameter. Accepted values are GL_BUFFER_ACCESS, GL_BUFFER_MAPPED, GL_BUFFER_SIZE, or GL_BUFFER_USAGE.
data: Returns the requested parameter.

glGetBufferParameteriv returns in data a selected parameter of the buffer object specified by target.

value names a specific buffer object parameter, as follows:

GL_BUFFER_ACCESS: params returns the access policy set while mapping the buffer object. The initial value is GL_READ_WRITE.
GL_BUFFER_MAPPED: params returns a flag indicating whether the buffer object is currently mapped. The initial value is GL_FALSE.
GL_BUFFER_SIZE: params returns the size of the buffer object, measured in bytes. The initial value is 0.
GL_BUFFER_USAGE: params returns the buffer object’s usage pattern. The initial value is GL_STATIC_DRAW.

GL_INVALID_ENUM is generated if target or value is not an accepted value.

GL_INVALID_OPERATION is generated if the reserved buffer object name 0 is bound to target.

GL_INVALID_OPERATION is generated if glGetBufferParameteriv is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetBufferPointerv target pname params

Return the pointer to a mapped buffer object’s data store.

target: Specifies the target buffer object. The symbolic constant must be GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.
pname: Specifies the pointer to be returned. The symbolic constant must be GL_BUFFER_MAP_POINTER.
params: Returns the pointer value specified by pname.

glGetBufferPointerv returns pointer information. pname is a symbolic constant indicating the pointer to be returned, which must be GL_BUFFER_MAP_POINTER, the pointer to which the buffer object’s data store is mapped. If the data store is not currently mapped, NULL is returned. params is a pointer to a location in which to place the returned pointer value.

GL_INVALID_ENUM is generated if target or pname is not an accepted value.

GL_INVALID_OPERATION is generated if the reserved buffer object name 0 is bound to target.

GL_INVALID_OPERATION is generated if glGetBufferPointerv is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetBufferSubData target offset size data

Returns a subset of a buffer object’s data store.

target: Specifies the target buffer object. The symbolic constant must be GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.
offset: Specifies the offset into the buffer object’s data store from which data will be returned, measured in bytes.
size: Specifies the size in bytes of the data store region being returned.
data: Specifies a pointer to the location where buffer object data is returned.

glGetBufferSubData returns some or all of the data from the buffer object currently bound to target. Data starting at byte offset offset and extending for size bytes is copied from the data store to the memory pointed to by data. An error is thrown if the buffer object is currently mapped, or if offset and size together define a range beyond the bounds of the buffer object’s data store.

GL_INVALID_ENUM is generated if target is not GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.

GL_INVALID_VALUE is generated if offset or size is negative, or if together they define a region of memory that extends beyond the buffer object’s allocated data store.

GL_INVALID_OPERATION is generated if the reserved buffer object name 0 is bound to target.

GL_INVALID_OPERATION is generated if the buffer object being queried is mapped.

GL_INVALID_OPERATION is generated if glGetBufferSubData is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetClipPlane plane equation

Return the coefficients of the specified clipping plane.

plane: Specifies a clipping plane. The number of clipping planes depends on the implementation, but at least six clipping planes are supported. They are identified by symbolic names of the form GL_CLIP_PLANEi where i ranges from 0 to the value of GL_MAX_CLIP_PLANES - 1.
equation: Returns four double-precision values that are the coefficients of the plane equation of plane in eye coordinates. The initial value is (0, 0, 0, 0).

glGetClipPlane returns in equation the four coefficients of the plane equation for plane.

GL_INVALID_ENUM is generated if plane is not an accepted value.

GL_INVALID_OPERATION is generated if glGetClipPlane is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetColorTableParameterfv target pname params

Function: void glGetColorTableParameteriv target pname params

Get color lookup table parameters.

target: The target color table. Must be GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, GL_POST_COLOR_MATRIX_COLOR_TABLE, GL_PROXY_COLOR_TABLE, GL_PROXY_POST_CONVOLUTION_COLOR_TABLE, or GL_PROXY_POST_COLOR_MATRIX_COLOR_TABLE.
pname: The symbolic name of a color lookup table parameter. Must be one of GL_COLOR_TABLE_BIAS, GL_COLOR_TABLE_SCALE, GL_COLOR_TABLE_FORMAT, GL_COLOR_TABLE_WIDTH, GL_COLOR_TABLE_RED_SIZE, GL_COLOR_TABLE_GREEN_SIZE, GL_COLOR_TABLE_BLUE_SIZE, GL_COLOR_TABLE_ALPHA_SIZE, GL_COLOR_TABLE_LUMINANCE_SIZE, or GL_COLOR_TABLE_INTENSITY_SIZE.
params: A pointer to an array where the values of the parameter will be stored.

Returns parameters specific to color table target.

When pname is set to GL_COLOR_TABLE_SCALE or GL_COLOR_TABLE_BIAS, glGetColorTableParameter returns the color table scale or bias parameters for the table specified by target. For these queries, target must be set to GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, or GL_POST_COLOR_MATRIX_COLOR_TABLE and params points to an array of four elements, which receive the scale or bias factors for red, green, blue, and alpha, in that order.

glGetColorTableParameter can also be used to retrieve the format and size parameters for a color table. For these queries, set target to either the color table target or the proxy color table target. The format and size parameters are set by glColorTable.

The following table lists the format and size parameters that may be queried. For each symbolic constant listed below for pname, params must point to an array of the given length and receive the values indicated.

Parameter: N, Meaning
GL_COLOR_TABLE_FORMAT: 1 , Internal format (e.g., GL_RGBA)
GL_COLOR_TABLE_WIDTH: 1 , Number of elements in table
GL_COLOR_TABLE_RED_SIZE: 1 , Size of red component, in bits
GL_COLOR_TABLE_GREEN_SIZE: 1 , Size of green component
GL_COLOR_TABLE_BLUE_SIZE: 1 , Size of blue component
GL_COLOR_TABLE_ALPHA_SIZE: 1 , Size of alpha component
GL_COLOR_TABLE_LUMINANCE_SIZE: 1 , Size of luminance component
GL_COLOR_TABLE_INTENSITY_SIZE: 1 , Size of intensity component

GL_INVALID_ENUM is generated if target or pname is not an acceptable value.

GL_INVALID_OPERATION is generated if glGetColorTableParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetColorTable target format type table

Retrieve contents of a color lookup table.

target: Must be GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, or GL_POST_COLOR_MATRIX_COLOR_TABLE.
format: The format of the pixel data in table. The possible values are GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, GL_BGR, GL_RGBA, and GL_BGRA.
type: The type of the pixel data in table. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
table: Pointer to a one-dimensional array of pixel data containing the contents of the color table.

glGetColorTable returns in table the contents of the color table specified by target. No pixel transfer operations are performed, but pixel storage modes that are applicable to glReadPixels are performed.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer) while a histogram table is requested, table is treated as a byte offset into the buffer object’s data store.

Color components that are requested in the specified format, but which are not included in the internal format of the color lookup table, are returned as zero. The assignments of internal color components to the components requested by format are

Internal Component: Resulting Component
Red: Red
Green: Green
Blue: Blue
Alpha: Alpha
Luminance: Red
Intensity: Red

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if type is not one of the allowable values.

GL_INVALID_OPERATION is generated if type is one of GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB.

GL_INVALID_OPERATION is generated if type is one of GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and format is neither GL_RGBA nor GL_BGRA.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the data would be packed to the buffer object such that the memory writes required would exceed the data store size.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and table is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

GL_INVALID_OPERATION is generated if glGetColorTable is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetCompressedTexImage target lod img

Return a compressed texture image.

target: Specifies which texture is to be obtained. GL_TEXTURE_1D, GL_TEXTURE_2D, and GL_TEXTURE_3DGL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, and GL_TEXTURE_CUBE_MAP_NEGATIVE_Z are accepted.
lod: Specifies the level-of-detail number of the desired image. Level 0 is the base image level. Level n is the nth mipmap reduction image.
img: Returns the compressed texture image.

glGetCompressedTexImage returns the compressed texture image associated with target and lod into img. img should be an array of GL_TEXTURE_COMPRESSED_IMAGE_SIZE bytes. target specifies whether the desired texture image was one specified by glTexImage1D (GL_TEXTURE_1D), glTexImage2D (GL_TEXTURE_2D or any of GL_TEXTURE_CUBE_MAP_*), or glTexImage3D (GL_TEXTURE_3D). lod specifies the level-of-detail number of the desired image.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer) while a texture image is requested, img is treated as a byte offset into the buffer object’s data store.

To minimize errors, first verify that the texture is compressed by calling glGetTexLevelParameter with argument GL_TEXTURE_COMPRESSED. If the texture is compressed, then determine the amount of memory required to store the compressed texture by calling glGetTexLevelParameter with argument GL_TEXTURE_COMPRESSED_IMAGE_SIZE. Finally, retrieve the internal format of the texture by calling glGetTexLevelParameter with argument GL_TEXTURE_INTERNAL_FORMAT. To store the texture for later use, associate the internal format and size with the retrieved texture image. These data can be used by the respective texture or subtexture loading routine used for loading target textures.

GL_INVALID_VALUE is generated if lod is less than zero or greater than the maximum number of LODs permitted by the implementation.

GL_INVALID_OPERATION is generated if glGetCompressedTexImage is used to retrieve a texture that is in an uncompressed internal format.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glGetCompressedTexImage is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetConvolutionFilter target format type image

Get current 1D or 2D convolution filter kernel.

target: The filter to be retrieved. Must be one of GL_CONVOLUTION_1D or GL_CONVOLUTION_2D.
format: Format of the output image. Must be one of GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
type: Data type of components in the output image. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
image: Pointer to storage for the output image.

glGetConvolutionFilter returns the current 1D or 2D convolution filter kernel as an image. The one- or two-dimensional image is placed in image according to the specifications in format and type. No pixel transfer operations are performed on this image, but the relevant pixel storage modes are applied.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer) while a convolution filter is requested, image is treated as a byte offset into the buffer object’s data store.

Color components that are present in format but not included in the internal format of the filter are returned as zero. The assignments of internal color components to the components of format are as follows.

Internal Component: Resulting Component
Red: Red
Green: Green
Blue: Blue
Alpha: Alpha
Luminance: Red
Intensity: Red

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if type is not one of the allowable values.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and image is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

GL_INVALID_OPERATION is generated if glGetConvolutionFilter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetConvolutionParameterfv target pname params

Function: void glGetConvolutionParameteriv target pname params

Get convolution parameters.

target: The filter whose parameters are to be retrieved. Must be one of GL_CONVOLUTION_1D, GL_CONVOLUTION_2D, or GL_SEPARABLE_2D.
pname: The parameter to be retrieved. Must be one of GL_CONVOLUTION_BORDER_MODE, GL_CONVOLUTION_BORDER_COLOR, GL_CONVOLUTION_FILTER_SCALE, GL_CONVOLUTION_FILTER_BIAS, GL_CONVOLUTION_FORMAT, GL_CONVOLUTION_WIDTH, GL_CONVOLUTION_HEIGHT, GL_MAX_CONVOLUTION_WIDTH, or GL_MAX_CONVOLUTION_HEIGHT.
params: Pointer to storage for the parameters to be retrieved.

glGetConvolutionParameter retrieves convolution parameters. target determines which convolution filter is queried. pname determines which parameter is returned:

GL_CONVOLUTION_BORDER_MODE: The convolution border mode. See glConvolutionParameter for a list of border modes.
GL_CONVOLUTION_BORDER_COLOR: The current convolution border color. params must be a pointer to an array of four elements, which will receive the red, green, blue, and alpha border colors.
GL_CONVOLUTION_FILTER_SCALE: The current filter scale factors. params must be a pointer to an array of four elements, which will receive the red, green, blue, and alpha filter scale factors in that order.
GL_CONVOLUTION_FILTER_BIAS: The current filter bias factors. params must be a pointer to an array of four elements, which will receive the red, green, blue, and alpha filter bias terms in that order.
GL_CONVOLUTION_FORMAT: The current internal format. See glConvolutionFilter1D, glConvolutionFilter2D, and glSeparableFilter2D for lists of allowable formats.
GL_CONVOLUTION_WIDTH: The current filter image width.
GL_CONVOLUTION_HEIGHT: The current filter image height.
GL_MAX_CONVOLUTION_WIDTH: The maximum acceptable filter image width.
GL_MAX_CONVOLUTION_HEIGHT: The maximum acceptable filter image height.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if pname is not one of the allowable values.

GL_INVALID_ENUM is generated if target is GL_CONVOLUTION_1D and pname is GL_CONVOLUTION_HEIGHT or GL_MAX_CONVOLUTION_HEIGHT.

GL_INVALID_OPERATION is generated if glGetConvolutionParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLenum glGetError

Return error information.

glGetError returns the value of the error flag. Each detectable error is assigned a numeric code and symbolic name. When an error occurs, the error flag is set to the appropriate error code value. No other errors are recorded until glGetError is called, the error code is returned, and the flag is reset to GL_NO_ERROR. If a call to glGetError returns GL_NO_ERROR, there has been no detectable error since the last call to glGetError, or since the GL was initialized.

To allow for distributed implementations, there may be several error flags. If any single error flag has recorded an error, the value of that flag is returned and that flag is reset to GL_NO_ERROR when glGetError is called. If more than one flag has recorded an error, glGetError returns and clears an arbitrary error flag value. Thus, glGetError should always be called in a loop, until it returns GL_NO_ERROR, if all error flags are to be reset.

Initially, all error flags are set to GL_NO_ERROR.

The following errors are currently defined:

GL_NO_ERROR: No error has been recorded. The value of this symbolic constant is guaranteed to be 0.
GL_INVALID_ENUM: An unacceptable value is specified for an enumerated argument. The offending command is ignored and has no other side effect than to set the error flag.
GL_INVALID_VALUE: A numeric argument is out of range. The offending command is ignored and has no other side effect than to set the error flag.
GL_INVALID_OPERATION: The specified operation is not allowed in the current state. The offending command is ignored and has no other side effect than to set the error flag.
GL_STACK_OVERFLOW: This command would cause a stack overflow. The offending command is ignored and has no other side effect than to set the error flag.
GL_STACK_UNDERFLOW: This command would cause a stack underflow. The offending command is ignored and has no other side effect than to set the error flag.
GL_OUT_OF_MEMORY: There is not enough memory left to execute the command. The state of the GL is undefined, except for the state of the error flags, after this error is recorded.
GL_TABLE_TOO_LARGE: The specified table exceeds the implementation’s maximum supported table size. The offending command is ignored and has no other side effect than to set the error flag.

When an error flag is set, results of a GL operation are undefined only if GL_OUT_OF_MEMORY has occurred. In all other cases, the command generating the error is ignored and has no effect on the GL state or frame buffer contents. If the generating command returns a value, it returns 0. If glGetError itself generates an error, it returns 0.

GL_INVALID_OPERATION is generated if glGetError is executed between the execution of glBegin and the corresponding execution of glEnd. In this case, glGetError returns 0.

Function: void glGetHistogramParameterfv target pname params

Function: void glGetHistogramParameteriv target pname params

Get histogram parameters.

target: Must be one of GL_HISTOGRAM or GL_PROXY_HISTOGRAM.
pname: The name of the parameter to be retrieved. Must be one of GL_HISTOGRAM_WIDTH, GL_HISTOGRAM_FORMAT, GL_HISTOGRAM_RED_SIZE, GL_HISTOGRAM_GREEN_SIZE, GL_HISTOGRAM_BLUE_SIZE, GL_HISTOGRAM_ALPHA_SIZE, GL_HISTOGRAM_LUMINANCE_SIZE, or GL_HISTOGRAM_SINK.
params: Pointer to storage for the returned values.

glGetHistogramParameter is used to query parameter values for the current histogram or for a proxy. The histogram state information may be queried by calling glGetHistogramParameter with a target of GL_HISTOGRAM (to obtain information for the current histogram table) or GL_PROXY_HISTOGRAM (to obtain information from the most recent proxy request) and one of the following values for the pname argument:

Parameter: Description
GL_HISTOGRAM_WIDTH: Histogram table width
GL_HISTOGRAM_FORMAT: Internal format
GL_HISTOGRAM_RED_SIZE: Red component counter size, in bits
GL_HISTOGRAM_GREEN_SIZE: Green component counter size, in bits
GL_HISTOGRAM_BLUE_SIZE: Blue component counter size, in bits
GL_HISTOGRAM_ALPHA_SIZE: Alpha component counter size, in bits
GL_HISTOGRAM_LUMINANCE_SIZE: Luminance component counter size, in bits
GL_HISTOGRAM_SINK: Value of the sink parameter

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if pname is not one of the allowable values.

GL_INVALID_OPERATION is generated if glGetHistogramParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetHistogram target reset format type values

Get histogram table.

target: Must be GL_HISTOGRAM.
reset: If GL_TRUE, each component counter that is actually returned is reset to zero. (Other counters are unaffected.) If GL_FALSE, none of the counters in the histogram table is modified.
format: The format of values to be returned in values. Must be one of GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
type: The type of values to be returned in values. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
values: A pointer to storage for the returned histogram table.

glGetHistogram returns the current histogram table as a one-dimensional image with the same width as the histogram. No pixel transfer operations are performed on this image, but pixel storage modes that are applicable to 1D images are honored.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer) while a histogram table is requested, values is treated as a byte offset into the buffer object’s data store.

Color components that are requested in the specified format, but which are not included in the internal format of the histogram, are returned as zero. The assignments of internal color components to the components requested by format are:

Internal Component: Resulting Component
Red: Red
Green: Green
Blue: Blue
Alpha: Alpha
Luminance: Red

GL_INVALID_ENUM is generated if target is not GL_HISTOGRAM.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if type is not one of the allowable values.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and values is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

GL_INVALID_OPERATION is generated if glGetHistogram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetLightfv light pname params

Function: void glGetLightiv light pname params

Return light source parameter values.

light: Specifies a light source. The number of possible lights depends on the implementation, but at least eight lights are supported. They are identified by symbolic names of the form GL_LIGHTi where i ranges from 0 to the value of GL_MAX_LIGHTS - 1.
pname: Specifies a light source parameter for light. Accepted symbolic names are GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, GL_POSITION, GL_SPOT_DIRECTION, GL_SPOT_EXPONENT, GL_SPOT_CUTOFF, GL_CONSTANT_ATTENUATION, GL_LINEAR_ATTENUATION, and GL_QUADRATIC_ATTENUATION.
params: Returns the requested data.

glGetLight returns in params the value or values of a light source parameter. light names the light and is a symbolic name of the form GL_LIGHTi where i ranges from 0 to the value of GL_MAX_LIGHTS - 1. GL_MAX_LIGHTS is an implementation dependent constant that is greater than or equal to eight. pname specifies one of ten light source parameters, again by symbolic name.

The following parameters are defined:

GL_AMBIENT: params returns four integer or floating-point values representing the ambient intensity of the light source. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and -1.0 maps to the most negative representable integer value. If the internal value is outside the range [-1,1], the corresponding integer return value is undefined. The initial value is (0, 0, 0, 1).
GL_DIFFUSE: params returns four integer or floating-point values representing the diffuse intensity of the light source. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and -1.0 maps to the most negative representable integer value. If the internal value is outside the range [-1,1], the corresponding integer return value is undefined. The initial value for GL_LIGHT0 is (1, 1, 1, 1); for other lights, the initial value is (0, 0, 0, 0).
GL_SPECULAR: params returns four integer or floating-point values representing the specular intensity of the light source. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and -1.0 maps to the most negative representable integer value. If the internal value is outside the range [-1,1], the corresponding integer return value is undefined. The initial value for GL_LIGHT0 is (1, 1, 1, 1); for other lights, the initial value is (0, 0, 0, 0).
GL_POSITION: params returns four integer or floating-point values representing the position of the light source. Integer values, when requested, are computed by rounding the internal floating-point values to the nearest integer value. The returned values are those maintained in eye coordinates. They will not be equal to the values specified using glLight, unless the modelview matrix was identity at the time glLight was called. The initial value is (0, 0, 1, 0).
GL_SPOT_DIRECTION: params returns three integer or floating-point values representing the direction of the light source. Integer values, when requested, are computed by rounding the internal floating-point values to the nearest integer value. The returned values are those maintained in eye coordinates. They will not be equal to the values specified using glLight, unless the modelview matrix was identity at the time glLight was called. Although spot direction is normalized before being used in the lighting equation, the returned values are the transformed versions of the specified values prior to normalization. The initial value is (0,0-1).
GL_SPOT_EXPONENT: params returns a single integer or floating-point value representing the spot exponent of the light. An integer value, when requested, is computed by rounding the internal floating-point representation to the nearest integer. The initial value is 0.
GL_SPOT_CUTOFF: params returns a single integer or floating-point value representing the spot cutoff angle of the light. An integer value, when requested, is computed by rounding the internal floating-point representation to the nearest integer. The initial value is 180.
GL_CONSTANT_ATTENUATION: params returns a single integer or floating-point value representing the constant (not distance-related) attenuation of the light. An integer value, when requested, is computed by rounding the internal floating-point representation to the nearest integer. The initial value is 1.
GL_LINEAR_ATTENUATION: params returns a single integer or floating-point value representing the linear attenuation of the light. An integer value, when requested, is computed by rounding the internal floating-point representation to the nearest integer. The initial value is 0.
GL_QUADRATIC_ATTENUATION: params returns a single integer or floating-point value representing the quadratic attenuation of the light. An integer value, when requested, is computed by rounding the internal floating-point representation to the nearest integer. The initial value is 0.

GL_INVALID_ENUM is generated if light or pname is not an accepted value.

GL_INVALID_OPERATION is generated if glGetLight is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetMapdv target query v

Function: void glGetMapfv target query v

Function: void glGetMapiv target query v

Return evaluator parameters.

target: Specifies the symbolic name of a map. Accepted values are GL_MAP1_COLOR_4, GL_MAP1_INDEX, GL_MAP1_NORMAL, GL_MAP1_TEXTURE_COORD_1, GL_MAP1_TEXTURE_COORD_2, GL_MAP1_TEXTURE_COORD_3, GL_MAP1_TEXTURE_COORD_4, GL_MAP1_VERTEX_3, GL_MAP1_VERTEX_4, GL_MAP2_COLOR_4, GL_MAP2_INDEX, GL_MAP2_NORMAL, GL_MAP2_TEXTURE_COORD_1, GL_MAP2_TEXTURE_COORD_2, GL_MAP2_TEXTURE_COORD_3, GL_MAP2_TEXTURE_COORD_4, GL_MAP2_VERTEX_3, and GL_MAP2_VERTEX_4.
query: Specifies which parameter to return. Symbolic names GL_COEFF, GL_ORDER, and GL_DOMAIN are accepted.
v: Returns the requested data.

glMap1 and glMap2 define evaluators. glGetMap returns evaluator parameters. target chooses a map, query selects a specific parameter, and v points to storage where the values will be returned.

The acceptable values for the target parameter are described in the glMap1 and glMap2 reference pages.

query can assume the following values:

GL_COEFF: v returns the control points for the evaluator function. One-dimensional evaluators return order control points, and two-dimensional evaluators return uorderÃvorder control points. Each control point consists of one, two, three, or four integer, single-precision floating-point, or double-precision floating-point values, depending on the type of the evaluator. The GL returns two-dimensional control points in row-major order, incrementing the uorder index quickly and the vorder index after each row. Integer values, when requested, are computed by rounding the internal floating-point values to the nearest integer values.
GL_ORDER: v returns the order of the evaluator function. One-dimensional evaluators return a single value, order. The initial value is 1. Two-dimensional evaluators return two values, uorder and vorder. The initial value is 1,1.
GL_DOMAIN: v returns the linear u and v mapping parameters. One-dimensional evaluators return two values, u1 and u2, as specified by glMap1. Two-dimensional evaluators return four values (u1, u2, v1, and v2) as specified by glMap2. Integer values, when requested, are computed by rounding the internal floating-point values to the nearest integer values.

GL_INVALID_ENUM is generated if either target or query is not an accepted value.

GL_INVALID_OPERATION is generated if glGetMap is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetMaterialfv face pname params

Function: void glGetMaterialiv face pname params

Return material parameters.

face: Specifies which of the two materials is being queried. GL_FRONT or GL_BACK are accepted, representing the front and back materials, respectively.
pname: Specifies the material parameter to return. GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, GL_EMISSION, GL_SHININESS, and GL_COLOR_INDEXES are accepted.
params: Returns the requested data.

glGetMaterial returns in params the value or values of parameter pname of material face. Six parameters are defined:

GL_AMBIENT: params returns four integer or floating-point values representing the ambient reflectance of the material. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and -1.0 maps to the most negative representable integer value. If the internal value is outside the range [-1,1], the corresponding integer return value is undefined. The initial value is (0.2, 0.2, 0.2, 1.0)
GL_DIFFUSE: params returns four integer or floating-point values representing the diffuse reflectance of the material. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and -1.0 maps to the most negative representable integer value. If the internal value is outside the range [-1,1], the corresponding integer return value is undefined. The initial value is (0.8, 0.8, 0.8, 1.0).
GL_SPECULAR: params returns four integer or floating-point values representing the specular reflectance of the material. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and -1.0 maps to the most negative representable integer value. If the internal value is outside the range [-1,1], the corresponding integer return value is undefined. The initial value is (0, 0, 0, 1).
GL_EMISSION: params returns four integer or floating-point values representing the emitted light intensity of the material. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and -1.0 maps to the most negative representable integer value. If the internal value is outside the range [-1,1], the corresponding integer return value is undefined. The initial value is (0, 0, 0, 1).
GL_SHININESS: params returns one integer or floating-point value representing the specular exponent of the material. Integer values, when requested, are computed by rounding the internal floating-point value to the nearest integer value. The initial value is 0.
GL_COLOR_INDEXES: params returns three integer or floating-point values representing the ambient, diffuse, and specular indices of the material. These indices are used only for color index lighting. (All the other parameters are used only for RGBA lighting.) Integer values, when requested, are computed by rounding the internal floating-point values to the nearest integer values.

GL_INVALID_ENUM is generated if face or pname is not an accepted value.

GL_INVALID_OPERATION is generated if glGetMaterial is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetMinmaxParameterfv target pname params

Function: void glGetMinmaxParameteriv target pname params

Get minmax parameters.

target: Must be GL_MINMAX.
pname: The parameter to be retrieved. Must be one of GL_MINMAX_FORMAT or GL_MINMAX_SINK.
params: A pointer to storage for the retrieved parameters.

glGetMinmaxParameter retrieves parameters for the current minmax table by setting pname to one of the following values:

Parameter: Description
GL_MINMAX_FORMAT: Internal format of minmax table
GL_MINMAX_SINK: Value of the sink parameter

GL_INVALID_ENUM is generated if target is not GL_MINMAX.

GL_INVALID_ENUM is generated if pname is not one of the allowable values.

GL_INVALID_OPERATION is generated if glGetMinmaxParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetMinmax target reset format types values

Get minimum and maximum pixel values.

target: Must be GL_MINMAX.
reset: If GL_TRUE, all entries in the minmax table that are actually returned are reset to their initial values. (Other entries are unaltered.) If GL_FALSE, the minmax table is unaltered.
format: The format of the data to be returned in values. Must be one of GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
types: The type of the data to be returned in values. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
values: A pointer to storage for the returned values.

glGetMinmax returns the accumulated minimum and maximum pixel values (computed on a per-component basis) in a one-dimensional image of width 2. The first set of return values are the minima, and the second set of return values are the maxima. The format of the return values is determined by format, and their type is determined by types.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer) while minimum and maximum pixel values are requested, values is treated as a byte offset into the buffer object’s data store.

No pixel transfer operations are performed on the return values, but pixel storage modes that are applicable to one-dimensional images are performed. Color components that are requested in the specified format, but that are not included in the internal format of the minmax table, are returned as zero. The assignment of internal color components to the components requested by format are as follows:

Internal Component: Resulting Component
Red: Red
Green: Green
Blue: Blue
Alpha: Alpha
Luminance: Red

If reset is GL_TRUE, the minmax table entries corresponding to the return values are reset to their initial values. Minimum and maximum values that are not returned are not modified, even if reset is GL_TRUE.

GL_INVALID_ENUM is generated if target is not GL_MINMAX.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if types is not one of the allowable values.

GL_INVALID_OPERATION is generated if types is one of GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB.

GL_INVALID_OPERATION is generated if types is one of GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and format is neither GL_RGBA nor GL_BGRA.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glGetMinmax is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetPixelMapfv map data

Function: void glGetPixelMapuiv map data

Function: void glGetPixelMapusv map data

Return the specified pixel map.

map: Specifies the name of the pixel map to return. Accepted values are GL_PIXEL_MAP_I_TO_I, GL_PIXEL_MAP_S_TO_S, GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, GL_PIXEL_MAP_I_TO_A, GL_PIXEL_MAP_R_TO_R, GL_PIXEL_MAP_G_TO_G, GL_PIXEL_MAP_B_TO_B, and GL_PIXEL_MAP_A_TO_A.
data: Returns the pixel map contents.

See the glPixelMap reference page for a description of the acceptable values for the map parameter. glGetPixelMap returns in data the contents of the pixel map specified in map. Pixel maps are used during the execution of glReadPixels, glDrawPixels, glCopyPixels, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, and glCopyTexSubImage3D. to map color indices, stencil indices, color components, and depth components to other values.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer) while a pixel map is requested, data is treated as a byte offset into the buffer object’s data store.

Unsigned integer values, if requested, are linearly mapped from the internal fixed or floating-point representation such that 1.0 maps to the largest representable integer value, and 0.0 maps to 0. Return unsigned integer values are undefined if the map value was not in the range [0,1].

To determine the required size of map, call glGet with the appropriate symbolic constant.

GL_INVALID_ENUM is generated if map is not an accepted value.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated by glGetPixelMapfv if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and data is not evenly divisible into the number of bytes needed to store in memory a GLfloat datum.

GL_INVALID_OPERATION is generated by glGetPixelMapuiv if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and data is not evenly divisible into the number of bytes needed to store in memory a GLuint datum.

GL_INVALID_OPERATION is generated by glGetPixelMapusv if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and data is not evenly divisible into the number of bytes needed to store in memory a GLushort datum.

GL_INVALID_OPERATION is generated if glGetPixelMap is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetPointerv pname params

Return the address of the specified pointer.

pname: Specifies the array or buffer pointer to be returned. Symbolic constants GL_COLOR_ARRAY_POINTER, GL_EDGE_FLAG_ARRAY_POINTER, GL_FOG_COORD_ARRAY_POINTER, GL_FEEDBACK_BUFFER_POINTER, GL_INDEX_ARRAY_POINTER, GL_NORMAL_ARRAY_POINTER, GL_SECONDARY_COLOR_ARRAY_POINTER, GL_SELECTION_BUFFER_POINTER, GL_TEXTURE_COORD_ARRAY_POINTER, or GL_VERTEX_ARRAY_POINTER are accepted.
params: Returns the pointer value specified by pname.

glGetPointerv returns pointer information. pname is a symbolic constant indicating the pointer to be returned, and params is a pointer to a location in which to place the returned data.

For all pname arguments except GL_FEEDBACK_BUFFER_POINTER and GL_SELECTION_BUFFER_POINTER, if a non-zero named buffer object was bound to the GL_ARRAY_BUFFER target (see glBindBuffer) when the desired pointer was previously specified, the pointer returned is a byte offset into the buffer object’s data store. Buffer objects are only available in OpenGL versions 1.5 and greater.

GL_INVALID_ENUM is generated if pname is not an accepted value.

Function: void glGetPolygonStipple pattern

Return the polygon stipple pattern.

pattern: Returns the stipple pattern. The initial value is all 1’s.

glGetPolygonStipple returns to pattern a 32Ã32 polygon stipple pattern. The pattern is packed into memory as if glReadPixels with both height and width of 32, type of GL_BITMAP, and format of GL_COLOR_INDEX were called, and the stipple pattern were stored in an internal 32Ã32 color index buffer. Unlike glReadPixels, however, pixel transfer operations (shift, offset, pixel map) are not applied to the returned stipple image.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer) while a polygon stipple pattern is requested, pattern is treated as a byte offset into the buffer object’s data store.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glGetPolygonStipple is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetProgramInfoLog program maxLength length infoLog

Returns the information log for a program object.

program: Specifies the program object whose information log is to be queried.
maxLength: Specifies the size of the character buffer for storing the returned information log.
length: Returns the length of the string returned in infoLog (excluding the null terminator).
infoLog: Specifies an array of characters that is used to return the information log.

glGetProgramInfoLog returns the information log for the specified program object. The information log for a program object is modified when the program object is linked or validated. The string that is returned will be null terminated.

glGetProgramInfoLog returns in infoLog as much of the information log as it can, up to a maximum of maxLength characters. The number of characters actually returned, excluding the null termination character, is specified by length. If the length of the returned string is not required, a value of NULL can be passed in the length argument. The size of the buffer required to store the returned information log can be obtained by calling glGetProgram with the value GL_INFO_LOG_LENGTH.

The information log for a program object is either an empty string, or a string containing information about the last link operation, or a string containing information about the last validation operation. It may contain diagnostic messages, warning messages, and other information. When a program object is created, its information log will be a string of length 0.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_VALUE is generated if maxLength is less than 0.

GL_INVALID_OPERATION is generated if glGetProgramInfoLog is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetProgramiv program pname params

Returns a parameter from a program object.

program: Specifies the program object to be queried.
pname: Specifies the object parameter. Accepted symbolic names are GL_DELETE_STATUS, GL_LINK_STATUS, GL_VALIDATE_STATUS, GL_INFO_LOG_LENGTH, GL_ATTACHED_SHADERS, GL_ACTIVE_ATTRIBUTES, GL_ACTIVE_ATTRIBUTE_MAX_LENGTH, GL_ACTIVE_UNIFORMS, GL_ACTIVE_UNIFORM_MAX_LENGTH.
params: Returns the requested object parameter.

glGetProgram returns in params the value of a parameter for a specific program object. The following parameters are defined:

GL_DELETE_STATUS: params returns GL_TRUE if program is currently flagged for deletion, and GL_FALSE otherwise.
GL_LINK_STATUS: params returns GL_TRUE if the last link operation on program was successful, and GL_FALSE otherwise.
GL_VALIDATE_STATUS: params returns GL_TRUE or if the last validation operation on program was successful, and GL_FALSE otherwise.
GL_INFO_LOG_LENGTH: params returns the number of characters in the information log for program including the null termination character (i.e., the size of the character buffer required to store the information log). If program has no information log, a value of 0 is returned.
GL_ATTACHED_SHADERS: params returns the number of shader objects attached to program.
GL_ACTIVE_ATTRIBUTES: params returns the number of active attribute variables for program.
GL_ACTIVE_ATTRIBUTE_MAX_LENGTH: params returns the length of the longest active attribute name for program, including the null termination character (i.e., the size of the character buffer required to store the longest attribute name). If no active attributes exist, 0 is returned.
GL_ACTIVE_UNIFORMS: params returns the number of active uniform variables for program.
GL_ACTIVE_UNIFORM_MAX_LENGTH: params returns the length of the longest active uniform variable name for program, including the null termination character (i.e., the size of the character buffer required to store the longest uniform variable name). If no active uniform variables exist, 0 is returned.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program does not refer to a program object.

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_OPERATION is generated if glGetProgram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetQueryiv target pname params

Return parameters of a query object target.

target: Specifies a query object target. Must be GL_SAMPLES_PASSED.
pname: Specifies the symbolic name of a query object target parameter. Accepted values are GL_CURRENT_QUERY or GL_QUERY_COUNTER_BITS.
params: Returns the requested data.

glGetQueryiv returns in params a selected parameter of the query object target specified by target.

pname names a specific query object target parameter. When target is GL_SAMPLES_PASSED, pname can be as follows:

GL_CURRENT_QUERY: params returns the name of the currently active occlusion query object. If no occlusion query is active, 0 is returned. The initial value is 0.
GL_QUERY_COUNTER_BITS: params returns the number of bits in the query counter used to accumulate passing samples. If the number of bits returned is 0, the implementation does not support a query counter, and the results obtained from glGetQueryObject are useless.

GL_INVALID_ENUM is generated if target or pname is not an accepted value.

GL_INVALID_OPERATION is generated if glGetQueryiv is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetQueryObjectiv id pname params

Function: void glGetQueryObjectuiv id pname params

Return parameters of a query object.

id: Specifies the name of a query object.
pname: Specifies the symbolic name of a query object parameter. Accepted values are GL_QUERY_RESULT or GL_QUERY_RESULT_AVAILABLE.
params: Returns the requested data.

glGetQueryObject returns in params a selected parameter of the query object specified by id.

pname names a specific query object parameter. pname can be as follows:

GL_QUERY_RESULT: params returns the value of the query object’s passed samples counter. The initial value is 0.
GL_QUERY_RESULT_AVAILABLE: params returns whether the passed samples counter is immediately available. If a delay would occur waiting for the query result, GL_FALSE is returned. Otherwise, GL_TRUE is returned, which also indicates that the results of all previous queries are available as well.

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_OPERATION is generated if id is not the name of a query object.

GL_INVALID_OPERATION is generated if id is the name of a currently active query object.

GL_INVALID_OPERATION is generated if glGetQueryObject is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetSeparableFilter target format type row column span

Get separable convolution filter kernel images.

target: The separable filter to be retrieved. Must be GL_SEPARABLE_2D.
format: Format of the output images. Must be one of GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGRGL_RGBA, GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
type: Data type of components in the output images. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
row: Pointer to storage for the row filter image.
column: Pointer to storage for the column filter image.
span: Pointer to storage for the span filter image (currently unused).

glGetSeparableFilter returns the two one-dimensional filter kernel images for the current separable 2D convolution filter. The row image is placed in row and the column image is placed in column according to the specifications in format and type. (In the current implementation, span is not affected in any way.) No pixel transfer operations are performed on the images, but the relevant pixel storage modes are applied.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer) while a separable convolution filter is requested, row, column, and span are treated as a byte offset into the buffer object’s data store.

Color components that are present in format but not included in the internal format of the filters are returned as zero. The assignments of internal color components to the components of format are as follows:

Internal Component: Resulting Component
Red: Red
Green: Green
Blue: Blue
Alpha: Alpha
Luminance: Red
Intensity: Red

GL_INVALID_ENUM is generated if target is not GL_SEPARABLE_2D.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if type is not one of the allowable values.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and row or column is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

GL_INVALID_OPERATION is generated if glGetSeparableFilter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetShaderInfoLog shader maxLength length infoLog

Returns the information log for a shader object.

shader: Specifies the shader object whose information log is to be queried.
maxLength: Specifies the size of the character buffer for storing the returned information log.
length: Returns the length of the string returned in infoLog (excluding the null terminator).
infoLog: Specifies an array of characters that is used to return the information log.

glGetShaderInfoLog returns the information log for the specified shader object. The information log for a shader object is modified when the shader is compiled. The string that is returned will be null terminated.

glGetShaderInfoLog returns in infoLog as much of the information log as it can, up to a maximum of maxLength characters. The number of characters actually returned, excluding the null termination character, is specified by length. If the length of the returned string is not required, a value of NULL can be passed in the length argument. The size of the buffer required to store the returned information log can be obtained by calling glGetShader with the value GL_INFO_LOG_LENGTH.

The information log for a shader object is a string that may contain diagnostic messages, warning messages, and other information about the last compile operation. When a shader object is created, its information log will be a string of length 0.

GL_INVALID_VALUE is generated if shader is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if shader is not a shader object.

GL_INVALID_VALUE is generated if maxLength is less than 0.

GL_INVALID_OPERATION is generated if glGetShaderInfoLog is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetShaderSource shader bufSize length source

Returns the source code string from a shader object.

shader: Specifies the shader object to be queried.
bufSize: Specifies the size of the character buffer for storing the returned source code string.
length: Returns the length of the string returned in source (excluding the null terminator).
source: Specifies an array of characters that is used to return the source code string.

glGetShaderSource returns the concatenation of the source code strings from the shader object specified by shader. The source code strings for a shader object are the result of a previous call to glShaderSource. The string returned by the function will be null terminated.

glGetShaderSource returns in source as much of the source code string as it can, up to a maximum of bufSize characters. The number of characters actually returned, excluding the null termination character, is specified by length. If the length of the returned string is not required, a value of NULL can be passed in the length argument. The size of the buffer required to store the returned source code string can be obtained by calling glGetShader with the value GL_SHADER_SOURCE_LENGTH.

GL_INVALID_VALUE is generated if shader is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if shader is not a shader object.

GL_INVALID_VALUE is generated if bufSize is less than 0.

GL_INVALID_OPERATION is generated if glGetShaderSource is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetShaderiv shader pname params

Returns a parameter from a shader object.

shader: Specifies the shader object to be queried.
pname: Specifies the object parameter. Accepted symbolic names are GL_SHADER_TYPE, GL_DELETE_STATUS, GL_COMPILE_STATUS, GL_INFO_LOG_LENGTH, GL_SHADER_SOURCE_LENGTH.
params: Returns the requested object parameter.

glGetShader returns in params the value of a parameter for a specific shader object. The following parameters are defined:

GL_SHADER_TYPE: params returns GL_VERTEX_SHADER if shader is a vertex shader object, and GL_FRAGMENT_SHADER if shader is a fragment shader object.
GL_DELETE_STATUS: params returns GL_TRUE if shader is currently flagged for deletion, and GL_FALSE otherwise.
GL_COMPILE_STATUS: params returns GL_TRUE if the last compile operation on shader was successful, and GL_FALSE otherwise.
GL_INFO_LOG_LENGTH: params returns the number of characters in the information log for shader including the null termination character (i.e., the size of the character buffer required to store the information log). If shader has no information log, a value of 0 is returned.
GL_SHADER_SOURCE_LENGTH: params returns the length of the concatenation of the source strings that make up the shader source for the shader, including the null termination character. (i.e., the size of the character buffer required to store the shader source). If no source code exists, 0 is returned.

GL_INVALID_VALUE is generated if shader is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if shader does not refer to a shader object.

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_OPERATION is generated if glGetShader is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: const-GLubyte* glGetString name

Return a string describing the current GL connection.

name: Specifies a symbolic constant, one of GL_VENDOR, GL_RENDERER, GL_VERSION, GL_SHADING_LANGUAGE_VERSION, or GL_EXTENSIONS.

glGetString returns a pointer to a static string describing some aspect of the current GL connection. name can be one of the following:

GL_VENDOR: Returns the company responsible for this GL implementation. This name does not change from release to release.
GL_RENDERER: Returns the name of the renderer. This name is typically specific to a particular configuration of a hardware platform. It does not change from release to release.
GL_VERSION: Returns a version or release number.
GL_SHADING_LANGUAGE_VERSION: Returns a version or release number for the shading language.
GL_EXTENSIONS: Returns a space-separated list of supported extensions to GL.

Because the GL does not include queries for the performance characteristics of an implementation, some applications are written to recognize known platforms and modify their GL usage based on known performance characteristics of these platforms. Strings GL_VENDOR and GL_RENDERER together uniquely specify a platform. They do not change from release to release and should be used by platform-recognition algorithms.

Some applications want to make use of features that are not part of the standard GL. These features may be implemented as extensions to the standard GL. The GL_EXTENSIONS string is a space-separated list of supported GL extensions. (Extension names never contain a space character.)

The GL_VERSION and GL_SHADING_LANGUAGE_VERSION strings begin with a version number. The version number uses one of these forms:

major_number.minor_numbermajor_number.minor_number.release_number

Vendor-specific information may follow the version number. Its format depends on the implementation, but a space always separates the version number and the vendor-specific information.

All strings are null-terminated.

GL_INVALID_ENUM is generated if name is not an accepted value.

GL_INVALID_OPERATION is generated if glGetString is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetTexEnvfv target pname params

Function: void glGetTexEnviv target pname params

Return texture environment parameters.

target: Specifies a texture environment. May be GL_TEXTURE_ENV, GL_TEXTURE_FILTER_CONTROL, or GL_POINT_SPRITE.
pname: Specifies the symbolic name of a texture environment parameter. Accepted values are GL_TEXTURE_ENV_MODE, GL_TEXTURE_ENV_COLOR, GL_TEXTURE_LOD_BIAS, GL_COMBINE_RGB, GL_COMBINE_ALPHA, GL_SRC0_RGB, GL_SRC1_RGB, GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, GL_SRC2_ALPHA, GL_OPERAND0_RGB, GL_OPERAND1_RGB, GL_OPERAND2_RGB, GL_OPERAND0_ALPHA, GL_OPERAND1_ALPHA, GL_OPERAND2_ALPHA, GL_RGB_SCALE, GL_ALPHA_SCALE, or GL_COORD_REPLACE.
params: Returns the requested data.

glGetTexEnv returns in params selected values of a texture environment that was specified with glTexEnv. target specifies a texture environment.

When target is GL_TEXTURE_FILTER_CONTROL, pname must be GL_TEXTURE_LOD_BIAS. When target is GL_POINT_SPRITE, pname must be GL_COORD_REPLACE. When target is GL_TEXTURE_ENV, pname can be GL_TEXTURE_ENV_MODE, GL_TEXTURE_ENV_COLOR, GL_COMBINE_RGB, GL_COMBINE_ALPHA, GL_RGB_SCALE, GL_ALPHA_SCALE, GL_SRC0_RGB, GL_SRC1_RGB, GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, or GL_SRC2_ALPHA.

pname names a specific texture environment parameter, as follows:

GL_TEXTURE_ENV_MODE: params returns the single-valued texture environment mode, a symbolic constant. The initial value is GL_MODULATE.
GL_TEXTURE_ENV_COLOR: params returns four integer or floating-point values that are the texture environment color. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer, and -1.0 maps to the most negative representable integer. The initial value is (0, 0, 0, 0).
GL_TEXTURE_LOD_BIAS: params returns a single floating-point value that is the texture level-of-detail bias. The initial value is 0.
GL_COMBINE_RGB: params returns a single symbolic constant value representing the current RGB combine mode. The initial value is GL_MODULATE.
GL_COMBINE_ALPHA: params returns a single symbolic constant value representing the current alpha combine mode. The initial value is GL_MODULATE.
GL_SRC0_RGB: params returns a single symbolic constant value representing the texture combiner zero’s RGB source. The initial value is GL_TEXTURE.
GL_SRC1_RGB: params returns a single symbolic constant value representing the texture combiner one’s RGB source. The initial value is GL_PREVIOUS.
GL_SRC2_RGB: params returns a single symbolic constant value representing the texture combiner two’s RGB source. The initial value is GL_CONSTANT.
GL_SRC0_ALPHA: params returns a single symbolic constant value representing the texture combiner zero’s alpha source. The initial value is GL_TEXTURE.
GL_SRC1_ALPHA: params returns a single symbolic constant value representing the texture combiner one’s alpha source. The initial value is GL_PREVIOUS.
GL_SRC2_ALPHA: params returns a single symbolic constant value representing the texture combiner two’s alpha source. The initial value is GL_CONSTANT.
GL_OPERAND0_RGB: params returns a single symbolic constant value representing the texture combiner zero’s RGB operand. The initial value is GL_SRC_COLOR.
GL_OPERAND1_RGB: params returns a single symbolic constant value representing the texture combiner one’s RGB operand. The initial value is GL_SRC_COLOR.
GL_OPERAND2_RGB: params returns a single symbolic constant value representing the texture combiner two’s RGB operand. The initial value is GL_SRC_ALPHA.
GL_OPERAND0_ALPHA: params returns a single symbolic constant value representing the texture combiner zero’s alpha operand. The initial value is GL_SRC_ALPHA.
GL_OPERAND1_ALPHA: params returns a single symbolic constant value representing the texture combiner one’s alpha operand. The initial value is GL_SRC_ALPHA.
GL_OPERAND2_ALPHA: params returns a single symbolic constant value representing the texture combiner two’s alpha operand. The initial value is GL_SRC_ALPHA.
GL_RGB_SCALE: params returns a single floating-point value representing the current RGB texture combiner scaling factor. The initial value is 1.0.
GL_ALPHA_SCALE: params returns a single floating-point value representing the current alpha texture combiner scaling factor. The initial value is 1.0.
GL_COORD_REPLACE: params returns a single boolean value representing the current point sprite texture coordinate replacement enable state. The initial value is GL_FALSE.

GL_INVALID_ENUM is generated if target or pname is not an accepted value.

GL_INVALID_OPERATION is generated if glGetTexEnv is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetTexGendv coord pname params

Function: void glGetTexGenfv coord pname params

Function: void glGetTexGeniv coord pname params

Return texture coordinate generation parameters.

coord: Specifies a texture coordinate. Must be GL_S, GL_T, GL_R, or GL_Q.
pname: Specifies the symbolic name of the value(s) to be returned. Must be either GL_TEXTURE_GEN_MODE or the name of one of the texture generation plane equations: GL_OBJECT_PLANE or GL_EYE_PLANE.
params: Returns the requested data.

glGetTexGen returns in params selected parameters of a texture coordinate generation function that was specified using glTexGen. coord names one of the (s, t, r, q) texture coordinates, using the symbolic constant GL_S, GL_T, GL_R, or GL_Q.

pname specifies one of three symbolic names:

GL_TEXTURE_GEN_MODE: params returns the single-valued texture generation function, a symbolic constant. The initial value is GL_EYE_LINEAR.
GL_OBJECT_PLANE: params returns the four plane equation coefficients that specify object linear-coordinate generation. Integer values, when requested, are mapped directly from the internal floating-point representation.
GL_EYE_PLANE: params returns the four plane equation coefficients that specify eye linear-coordinate generation. Integer values, when requested, are mapped directly from the internal floating-point representation. The returned values are those maintained in eye coordinates. They are not equal to the values specified using glTexGen, unless the modelview matrix was identity when glTexGen was called.

GL_INVALID_ENUM is generated if coord or pname is not an accepted value.

GL_INVALID_OPERATION is generated if glGetTexGen is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetTexImage target level format type img

Return a texture image.

target: Specifies which texture is to be obtained. GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, and GL_TEXTURE_CUBE_MAP_NEGATIVE_Z are accepted.
level: Specifies the level-of-detail number of the desired image. Level 0 is the base image level. Level n is the nth mipmap reduction image.
format: Specifies a pixel format for the returned data. The supported formats are GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: Specifies a pixel type for the returned data. The supported types are GL_UNSIGNED_BYTE, GL_BYTE, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
img: Returns the texture image. Should be a pointer to an array of the type specified by type.

glGetTexImage returns a texture image into img. target specifies whether the desired texture image is one specified by glTexImage1D (GL_TEXTURE_1D), glTexImage2D (GL_TEXTURE_2D or any of GL_TEXTURE_CUBE_MAP_*), or glTexImage3D (GL_TEXTURE_3D). level specifies the level-of-detail number of the desired image. format and type specify the format and type of the desired image array. See the reference pages glTexImage1D and glDrawPixels for a description of the acceptable values for the format and type parameters, respectively.

To understand the operation of glGetTexImage, consider the selected internal four-component texture image to be an RGBA color buffer the size of the image. The semantics of glGetTexImage are then identical to those of glReadPixels, with the exception that no pixel transfer operations are performed, when called with the same format and type, with x and y set to 0, width set to the width of the texture image (including border if one was specified), and height set to 1 for 1D images, or to the height of the texture image (including border if one was specified) for 2D images. Because the internal texture image is an RGBA image, pixel formats GL_COLOR_INDEX, GL_STENCIL_INDEX, and GL_DEPTH_COMPONENT are not accepted, and pixel type GL_BITMAP is not accepted.

If the selected texture image does not contain four components, the following mappings are applied. Single-component textures are treated as RGBA buffers with red set to the single-component value, green set to 0, blue set to 0, and alpha set to 1. Two-component textures are treated as RGBA buffers with red set to the value of component zero, alpha set to the value of component one, and green and blue set to 0. Finally, three-component textures are treated as RGBA buffers with red set to component zero, green set to component one, blue set to component two, and alpha set to 1.

To determine the required size of img, use glGetTexLevelParameter to determine the dimensions of the internal texture image, then scale the required number of pixels by the storage required for each pixel, based on format and type. Be sure to take the pixel storage parameters into account, especially GL_PACK_ALIGNMENT.

GL_INVALID_ENUM is generated if target, format, or type is not an accepted value.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2â¡(max,), where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_OPERATION is returned if type is one of GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB.

GL_INVALID_OPERATION is returned if type is one of GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV, and format is neither GL_RGBA or GL_BGRA.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and img is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

GL_INVALID_OPERATION is generated if glGetTexImage is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetTexLevelParameterfv target level pname params

Function: void glGetTexLevelParameteriv target level pname params

Return texture parameter values for a specific level of detail.

target: Specifies the symbolic name of the target texture, either GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_PROXY_TEXTURE_1D, GL_PROXY_TEXTURE_2D, GL_PROXY_TEXTURE_3D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, or GL_PROXY_TEXTURE_CUBE_MAP.
level: Specifies the level-of-detail number of the desired image. Level 0 is the base image level. Level n is the nth mipmap reduction image.
pname: Specifies the symbolic name of a texture parameter. GL_TEXTURE_WIDTH, GL_TEXTURE_HEIGHT, GL_TEXTURE_DEPTH, GL_TEXTURE_INTERNAL_FORMAT, GL_TEXTURE_BORDER, GL_TEXTURE_RED_SIZE, GL_TEXTURE_GREEN_SIZE, GL_TEXTURE_BLUE_SIZE, GL_TEXTURE_ALPHA_SIZE, GL_TEXTURE_LUMINANCE_SIZE, GL_TEXTURE_INTENSITY_SIZE, GL_TEXTURE_DEPTH_SIZE, GL_TEXTURE_COMPRESSED, and GL_TEXTURE_COMPRESSED_IMAGE_SIZE are accepted.
params: Returns the requested data.

glGetTexLevelParameter returns in params texture parameter values for a specific level-of-detail value, specified as level. target defines the target texture, either GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_PROXY_TEXTURE_1D, GL_PROXY_TEXTURE_2D, GL_PROXY_TEXTURE_3D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, or GL_PROXY_TEXTURE_CUBE_MAP.

GL_MAX_TEXTURE_SIZE, and GL_MAX_3D_TEXTURE_SIZE are not really descriptive enough. It has to report the largest square texture image that can be accommodated with mipmaps and borders, but a long skinny texture, or a texture without mipmaps and borders, may easily fit in texture memory. The proxy targets allow the user to more accurately query whether the GL can accommodate a texture of a given configuration. If the texture cannot be accommodated, the texture state variables, which may be queried with glGetTexLevelParameter, are set to 0. If the texture can be accommodated, the texture state values will be set as they would be set for a non-proxy target.

pname specifies the texture parameter whose value or values will be returned.

The accepted parameter names are as follows:

GL_TEXTURE_WIDTH: params returns a single value, the width of the texture image. This value includes the border of the texture image. The initial value is 0.
GL_TEXTURE_HEIGHT: params returns a single value, the height of the texture image. This value includes the border of the texture image. The initial value is 0.
GL_TEXTURE_DEPTH: params returns a single value, the depth of the texture image. This value includes the border of the texture image. The initial value is 0.
GL_TEXTURE_INTERNAL_FORMAT: params returns a single value, the internal format of the texture image.
GL_TEXTURE_BORDER: params returns a single value, the width in pixels of the border of the texture image. The initial value is 0.
GL_TEXTURE_RED_SIZE,
GL_TEXTURE_GREEN_SIZE,
GL_TEXTURE_BLUE_SIZE,
GL_TEXTURE_ALPHA_SIZE,
GL_TEXTURE_LUMINANCE_SIZE,
GL_TEXTURE_INTENSITY_SIZE,
GL_TEXTURE_DEPTH_SIZE: The internal storage resolution of an individual component. The resolution chosen by the GL will be a close match for the resolution requested by the user with the component argument of glTexImage1D, glTexImage2D, glTexImage3D, glCopyTexImage1D, and glCopyTexImage2D. The initial value is 0.
GL_TEXTURE_COMPRESSED: params returns a single boolean value indicating if the texture image is stored in a compressed internal format. The initiali value is GL_FALSE.
GL_TEXTURE_COMPRESSED_IMAGE_SIZE: params returns a single integer value, the number of unsigned bytes of the compressed texture image that would be returned from glGetCompressedTexImage.

GL_INVALID_ENUM is generated if target or pname is not an accepted value.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2max, where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_OPERATION is generated if glGetTexLevelParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

GL_INVALID_OPERATION is generated if GL_TEXTURE_COMPRESSED_IMAGE_SIZE is queried on texture images with an uncompressed internal format or on proxy targets.

Function: void glGetTexParameterfv target pname params

Function: void glGetTexParameteriv target pname params

Return texture parameter values.

target: Specifies the symbolic name of the target texture. GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, and GL_TEXTURE_CUBE_MAP are accepted.
pname: Specifies the symbolic name of a texture parameter. GL_TEXTURE_MAG_FILTER, GL_TEXTURE_MIN_FILTER, GL_TEXTURE_MIN_LOD, GL_TEXTURE_MAX_LOD, GL_TEXTURE_BASE_LEVEL, GL_TEXTURE_MAX_LEVEL, GL_TEXTURE_WRAP_S, GL_TEXTURE_WRAP_T, GL_TEXTURE_WRAP_R, GL_TEXTURE_BORDER_COLOR, GL_TEXTURE_PRIORITY, GL_TEXTURE_RESIDENT, GL_TEXTURE_COMPARE_MODE, GL_TEXTURE_COMPARE_FUNC, GL_DEPTH_TEXTURE_MODE, and GL_GENERATE_MIPMAP are accepted.
params: Returns the texture parameters.

glGetTexParameter returns in params the value or values of the texture parameter specified as pname. target defines the target texture, either GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, or GL_TEXTURE_CUBE_MAP, to specify one-, two-, or three-dimensional or cube-mapped texturing. pname accepts the same symbols as glTexParameter, with the same interpretations:

GL_TEXTURE_MAG_FILTER: Returns the single-valued texture magnification filter, a symbolic constant. The initial value is GL_LINEAR.
GL_TEXTURE_MIN_FILTER: Returns the single-valued texture minification filter, a symbolic constant. The initial value is GL_NEAREST_MIPMAP_LINEAR.
GL_TEXTURE_MIN_LOD: Returns the single-valued texture minimum level-of-detail value. The initial value is -1000.
GL_TEXTURE_MAX_LOD: Returns the single-valued texture maximum level-of-detail value. The initial value is 1000.
GL_TEXTURE_BASE_LEVEL: Returns the single-valued base texture mipmap level. The initial value is 0.
GL_TEXTURE_MAX_LEVEL: Returns the single-valued maximum texture mipmap array level. The initial value is 1000.
GL_TEXTURE_WRAP_S: Returns the single-valued wrapping function for texture coordinate s, a symbolic constant. The initial value is GL_REPEAT.
GL_TEXTURE_WRAP_T: Returns the single-valued wrapping function for texture coordinate t, a symbolic constant. The initial value is GL_REPEAT.
GL_TEXTURE_WRAP_R: Returns the single-valued wrapping function for texture coordinate r, a symbolic constant. The initial value is GL_REPEAT.
GL_TEXTURE_BORDER_COLOR: Returns four integer or floating-point numbers that comprise the RGBA color of the texture border. Floating-point values are returned in the range [0,1]. Integer values are returned as a linear mapping of the internal floating-point representation such that 1.0 maps to the most positive representable integer and -1.0 maps to the most negative representable integer. The initial value is (0, 0, 0, 0).
GL_TEXTURE_PRIORITY: Returns the residence priority of the target texture (or the named texture bound to it). The initial value is 1. See glPrioritizeTextures.
GL_TEXTURE_RESIDENT: Returns the residence status of the target texture. If the value returned in params is GL_TRUE, the texture is resident in texture memory. See glAreTexturesResident.
GL_TEXTURE_COMPARE_MODE: Returns a single-valued texture comparison mode, a symbolic constant. The initial value is GL_NONE. See glTexParameter.
GL_TEXTURE_COMPARE_FUNC: Returns a single-valued texture comparison function, a symbolic constant. The initial value is GL_LEQUAL. See glTexParameter.
GL_DEPTH_TEXTURE_MODE: Returns a single-valued texture format indicating how the depth values should be converted into color components. The initial value is GL_LUMINANCE. See glTexParameter.
GL_GENERATE_MIPMAP: Returns a single boolean value indicating if automatic mipmap level updates are enabled. See glTexParameter.

GL_INVALID_ENUM is generated if target or pname is not an accepted value.

GL_INVALID_OPERATION is generated if glGetTexParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLint glGetUniformLocation program name

Returns the location of a uniform variable.

program: Specifies the program object to be queried.
name: Points to a null terminated string containing the name of the uniform variable whose location is to be queried.

glGetUniformLocation returns an integer that represents the location of a specific uniform variable within a program object. name must be a null terminated string that contains no white space. name must be an active uniform variable name in program that is not a structure, an array of structures, or a subcomponent of a vector or a matrix. This function returns -1 if name does not correspond to an active uniform variable in program or if name starts with the reserved prefix "gl_".

Uniform variables that are structures or arrays of structures may be queried by calling glGetUniformLocation for each field within the structure. The array element operator "[]" and the structure field operator "." may be used in name in order to select elements within an array or fields within a structure. The result of using these operators is not allowed to be another structure, an array of structures, or a subcomponent of a vector or a matrix. Except if the last part of name indicates a uniform variable array, the location of the first element of an array can be retrieved by using the name of the array, or by using the name appended by "[0]".

The actual locations assigned to uniform variables are not known until the program object is linked successfully. After linking has occurred, the command glGetUniformLocation can be used to obtain the location of a uniform variable. This location value can then be passed to glUniform to set the value of the uniform variable or to glGetUniform in order to query the current value of the uniform variable. After a program object has been linked successfully, the index values for uniform variables remain fixed until the next link command occurs. Uniform variable locations and values can only be queried after a link if the link was successful.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_OPERATION is generated if program has not been successfully linked.

GL_INVALID_OPERATION is generated if glGetUniformLocation is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetUniformfv program location params

Function: void glGetUniformiv program location params

Returns the value of a uniform variable.

program: Specifies the program object to be queried.
location: Specifies the location of the uniform variable to be queried.
params: Returns the value of the specified uniform variable.

glGetUniform returns in params the value(s) of the specified uniform variable. The type of the uniform variable specified by location determines the number of values returned. If the uniform variable is defined in the shader as a boolean, int, or float, a single value will be returned. If it is defined as a vec2, ivec2, or bvec2, two values will be returned. If it is defined as a vec3, ivec3, or bvec3, three values will be returned, and so on. To query values stored in uniform variables declared as arrays, call glGetUniform for each element of the array. To query values stored in uniform variables declared as structures, call glGetUniform for each field in the structure. The values for uniform variables declared as a matrix will be returned in column major order.

The locations assigned to uniform variables are not known until the program object is linked. After linking has occurred, the command glGetUniformLocation can be used to obtain the location of a uniform variable. This location value can then be passed to glGetUniform in order to query the current value of the uniform variable. After a program object has been linked successfully, the index values for uniform variables remain fixed until the next link command occurs. The uniform variable values can only be queried after a link if the link was successful.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_OPERATION is generated if program has not been successfully linked.

GL_INVALID_OPERATION is generated if location does not correspond to a valid uniform variable location for the specified program object.

GL_INVALID_OPERATION is generated if glGetUniform is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glGetVertexAttribPointerv index pname pointer

Return the address of the specified generic vertex attribute pointer.

index: Specifies the generic vertex attribute parameter to be returned.
pname: Specifies the symbolic name of the generic vertex attribute parameter to be returned. Must be GL_VERTEX_ATTRIB_ARRAY_POINTER.
pointer: Returns the pointer value.

glGetVertexAttribPointerv returns pointer information. index is the generic vertex attribute to be queried, pname is a symbolic constant indicating the pointer to be returned, and params is a pointer to a location in which to place the returned data.

If a non-zero named buffer object was bound to the GL_ARRAY_BUFFER target (see glBindBuffer) when the desired pointer was previously specified, the pointer returned is a byte offset into the buffer object’s data store.

GL_INVALID_VALUE is generated if index is greater than or equal to GL_MAX_VERTEX_ATTRIBS.

GL_INVALID_ENUM is generated if pname is not an accepted value.

Function: void glGetVertexAttribdv index pname params

Function: void glGetVertexAttribfv index pname params

Function: void glGetVertexAttribiv index pname params

Return a generic vertex attribute parameter.

index: Specifies the generic vertex attribute parameter to be queried.
pname: Specifies the symbolic name of the vertex attribute parameter to be queried. Accepted values are GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING, GL_VERTEX_ATTRIB_ARRAY_ENABLED, GL_VERTEX_ATTRIB_ARRAY_SIZE, GL_VERTEX_ATTRIB_ARRAY_STRIDE, GL_VERTEX_ATTRIB_ARRAY_TYPE, GL_VERTEX_ATTRIB_ARRAY_NORMALIZED, or GL_CURRENT_VERTEX_ATTRIB.
params: Returns the requested data.

glGetVertexAttrib returns in params the value of a generic vertex attribute parameter. The generic vertex attribute to be queried is specified by index, and the parameter to be queried is specified by pname.

The accepted parameter names are as follows:

GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object currently bound to the binding point corresponding to generic vertex attribute array index. If no buffer object is bound, 0 is returned. The initial value is 0.
GL_VERTEX_ATTRIB_ARRAY_ENABLED: params returns a single value that is non-zero (true) if the vertex attribute array for index is enabled and 0 (false) if it is disabled. The initial value is GL_FALSE.
GL_VERTEX_ATTRIB_ARRAY_SIZE: params returns a single value, the size of the vertex attribute array for index. The size is the number of values for each element of the vertex attribute array, and it will be 1, 2, 3, or 4. The initial value is 4.
GL_VERTEX_ATTRIB_ARRAY_STRIDE: params returns a single value, the array stride for (number of bytes between successive elements in) the vertex attribute array for index. A value of 0 indicates that the array elements are stored sequentially in memory. The initial value is 0.
GL_VERTEX_ATTRIB_ARRAY_TYPE: params returns a single value, a symbolic constant indicating the array type for the vertex attribute array for index. Possible values are GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT, GL_FLOAT, and GL_DOUBLE. The initial value is GL_FLOAT.
GL_VERTEX_ATTRIB_ARRAY_NORMALIZED: params returns a single value that is non-zero (true) if fixed-point data types for the vertex attribute array indicated by index are normalized when they are converted to floating point, and 0 (false) otherwise. The initial value is GL_FALSE.
GL_CURRENT_VERTEX_ATTRIB: params returns four values that represent the current value for the generic vertex attribute specified by index. Generic vertex attribute 0 is unique in that it has no current state, so an error will be generated if index is 0. The initial value for all other generic vertex attributes is (0,0,0,1).

All of the parameters except GL_CURRENT_VERTEX_ATTRIB represent client-side state.

GL_INVALID_VALUE is generated if index is greater than or equal to GL_MAX_VERTEX_ATTRIBS.

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_OPERATION is generated if index is 0 and pname is GL_CURRENT_VERTEX_ATTRIB.

Function: void glGetBooleanv pname params

Function: void glGetDoublev pname params

Function: void glGetFloatv pname params

Function: void glGetIntegerv pname params

Return the value or values of a selected parameter.

pname: Specifies the parameter value to be returned. The symbolic constants in the list below are accepted.
params: Returns the value or values of the specified parameter.

These four commands return values for simple state variables in GL. pname is a symbolic constant indicating the state variable to be returned, and params is a pointer to an array of the indicated type in which to place the returned data.

Type conversion is performed if params has a different type than the state variable value being requested. If glGetBooleanv is called, a floating-point (or integer) value is converted to GL_FALSE if and only if it is 0.0 (or 0). Otherwise, it is converted to GL_TRUE. If glGetIntegerv is called, boolean values are returned as GL_TRUE or GL_FALSE, and most floating-point values are rounded to the nearest integer value. Floating-point colors and normals, however, are returned with a linear mapping that maps 1.0 to the most positive representable integer value and -1.0 to the most negative representable integer value. If glGetFloatv or glGetDoublev is called, boolean values are returned as GL_TRUE or GL_FALSE, and integer values are converted to floating-point values.

The following symbolic constants are accepted by pname:

GL_ACCUM_ALPHA_BITS: params returns one value, the number of alpha bitplanes in the accumulation buffer.
GL_ACCUM_BLUE_BITS: params returns one value, the number of blue bitplanes in the accumulation buffer.
GL_ACCUM_CLEAR_VALUE: params returns four values: the red, green, blue, and alpha values used to clear the accumulation buffer. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0, 0, 0, 0). See glClearAccum.
GL_ACCUM_GREEN_BITS: params returns one value, the number of green bitplanes in the accumulation buffer.
GL_ACCUM_RED_BITS: params returns one value, the number of red bitplanes in the accumulation buffer.
GL_ACTIVE_TEXTURE: params returns a single value indicating the active multitexture unit. The initial value is GL_TEXTURE0. See glActiveTexture.
GL_ALIASED_POINT_SIZE_RANGE: params returns two values, the smallest and largest supported sizes for aliased points.
GL_ALIASED_LINE_WIDTH_RANGE: params returns two values, the smallest and largest supported widths for aliased lines.
GL_ALPHA_BIAS: params returns one value, the alpha bias factor used during pixel transfers. The initial value is 0. See glPixelTransfer.
GL_ALPHA_BITS: params returns one value, the number of alpha bitplanes in each color buffer.
GL_ALPHA_SCALE: params returns one value, the alpha scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer.
GL_ALPHA_TEST: params returns a single boolean value indicating whether alpha testing of fragments is enabled. The initial value is GL_FALSE. See glAlphaFunc.
GL_ALPHA_TEST_FUNCparams returns one value,: the symbolic name of the alpha test function. The initial value is GL_ALWAYS. See glAlphaFunc.
GL_ALPHA_TEST_REF: params returns one value, the reference value for the alpha test. The initial value is 0. See glAlphaFunc. An integer value, if requested, is linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value.
GL_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object currently bound to the target GL_ARRAY_BUFFER. If no buffer object is bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_ATTRIB_STACK_DEPTH: params returns one value, the depth of the attribute stack. If the stack is empty, 0 is returned. The initial value is 0. See glPushAttrib.
GL_AUTO_NORMAL: params returns a single boolean value indicating whether 2D map evaluation automatically generates surface normals. The initial value is GL_FALSE. See glMap2.
GL_AUX_BUFFERS: params returns one value, the number of auxiliary color buffers available.
GL_BLEND: params returns a single boolean value indicating whether blending is enabled. The initial value is GL_FALSE. See glBlendFunc.
GL_BLEND_COLOR: params returns four values, the red, green, blue, and alpha values which are the components of the blend color. See glBlendColor.
GL_BLEND_DST_ALPHA: params returns one value, the symbolic constant identifying the alpha destination blend function. The initial value is GL_ZERO. See glBlendFunc and glBlendFuncSeparate.
GL_BLEND_DST_RGB: params returns one value, the symbolic constant identifying the RGB destination blend function. The initial value is GL_ZERO. See glBlendFunc and glBlendFuncSeparate.
GL_BLEND_EQUATION_RGB: params returns one value, a symbolic constant indicating whether the RGB blend equation is GL_FUNC_ADD, GL_FUNC_SUBTRACT, GL_FUNC_REVERSE_SUBTRACT, GL_MIN or GL_MAX. See glBlendEquationSeparate.
GL_BLEND_EQUATION_ALPHA: params returns one value, a symbolic constant indicating whether the Alpha blend equation is GL_FUNC_ADD, GL_FUNC_SUBTRACT, GL_FUNC_REVERSE_SUBTRACT, GL_MIN or GL_MAX. See glBlendEquationSeparate.
GL_BLEND_SRC_ALPHA: params returns one value, the symbolic constant identifying the alpha source blend function. The initial value is GL_ONE. See glBlendFunc and glBlendFuncSeparate.
GL_BLEND_SRC_RGB: params returns one value, the symbolic constant identifying the RGB source blend function. The initial value is GL_ONE. See glBlendFunc and glBlendFuncSeparate.
GL_BLUE_BIAS: params returns one value, the blue bias factor used during pixel transfers. The initial value is 0. See glPixelTransfer.
GL_BLUE_BITS: params returns one value, the number of blue bitplanes in each color buffer.
GL_BLUE_SCALE: params returns one value, the blue scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer.
GL_CLIENT_ACTIVE_TEXTURE: params returns a single integer value indicating the current client active multitexture unit. The initial value is GL_TEXTURE0. See glClientActiveTexture.
GL_CLIENT_ATTRIB_STACK_DEPTH: params returns one value indicating the depth of the attribute stack. The initial value is 0. See glPushClientAttrib.
GL_CLIP_PLANEi: params returns a single boolean value indicating whether the specified clipping plane is enabled. The initial value is GL_FALSE. See glClipPlane.
GL_COLOR_ARRAY: params returns a single boolean value indicating whether the color array is enabled. The initial value is GL_FALSE. See glColorPointer.
GL_COLOR_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object associated with the color array. This buffer object would have been bound to the target GL_ARRAY_BUFFER at the time of the most recent call to glColorPointer. If no buffer object was bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_COLOR_ARRAY_SIZE: params returns one value, the number of components per color in the color array. The initial value is 4. See glColorPointer.
GL_COLOR_ARRAY_STRIDE: params returns one value, the byte offset between consecutive colors in the color array. The initial value is 0. See glColorPointer.
GL_COLOR_ARRAY_TYPE: params returns one value, the data type of each component in the color array. The initial value is GL_FLOAT. See glColorPointer.
GL_COLOR_CLEAR_VALUE: params returns four values: the red, green, blue, and alpha values used to clear the color buffers. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0, 0, 0, 0). See glClearColor.
GL_COLOR_LOGIC_OP: params returns a single boolean value indicating whether a fragment’s RGBA color values are merged into the framebuffer using a logical operation. The initial value is GL_FALSE. See glLogicOp.
GL_COLOR_MATERIAL: params returns a single boolean value indicating whether one or more material parameters are tracking the current color. The initial value is GL_FALSE. See glColorMaterial.
GL_COLOR_MATERIAL_FACE: params returns one value, a symbolic constant indicating which materials have a parameter that is tracking the current color. The initial value is GL_FRONT_AND_BACK. See glColorMaterial.
GL_COLOR_MATERIAL_PARAMETER: params returns one value, a symbolic constant indicating which material parameters are tracking the current color. The initial value is GL_AMBIENT_AND_DIFFUSE. See glColorMaterial.
GL_COLOR_MATRIX: params returns sixteen values: the color matrix on the top of the color matrix stack. Initially this matrix is the identity matrix. See glPushMatrix.
GL_COLOR_MATRIX_STACK_DEPTH: params returns one value, the maximum supported depth of the projection matrix stack. The value must be at least 2. See glPushMatrix.
GL_COLOR_SUM: params returns a single boolean value indicating whether primary and secondary color sum is enabled. See glSecondaryColor.
GL_COLOR_TABLE: params returns a single boolean value indicating whether the color table lookup is enabled. See glColorTable.
GL_COLOR_WRITEMASK: params returns four boolean values: the red, green, blue, and alpha write enables for the color buffers. The initial value is (GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE). See glColorMask.
GL_COMPRESSED_TEXTURE_FORMATS: params returns a list of symbolic constants of length GL_NUM_COMPRESSED_TEXTURE_FORMATS indicating which compressed texture formats are available. See glCompressedTexImage2D.
GL_CONVOLUTION_1D: params returns a single boolean value indicating whether 1D convolution is enabled. The initial value is GL_FALSE. See glConvolutionFilter1D.
GL_CONVOLUTION_2D: params returns a single boolean value indicating whether 2D convolution is enabled. The initial value is GL_FALSE. See glConvolutionFilter2D.
GL_CULL_FACE: params returns a single boolean value indicating whether polygon culling is enabled. The initial value is GL_FALSE. See glCullFace.
GL_CULL_FACE_MODE: params returns one value, a symbolic constant indicating which polygon faces are to be culled. The initial value is GL_BACK. See glCullFace.
GL_CURRENT_COLOR: params returns four values: the red, green, blue, and alpha values of the current color. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (1, 1, 1, 1). See glColor.
GL_CURRENT_FOG_COORD: params returns one value, the current fog coordinate. The initial value is 0. See glFogCoord.
GL_CURRENT_INDEX: params returns one value, the current color index. The initial value is 1. See glIndex.
GL_CURRENT_NORMAL: params returns three values: the x, y, and z values of the current normal. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0, 0, 1). See glNormal.
GL_CURRENT_PROGRAM: params returns one value, the name of the program object that is currently active, or 0 if no program object is active. See glUseProgram.
GL_CURRENT_RASTER_COLOR: params returns four values: the red, green, blue, and alpha color values of the current raster position. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (1, 1, 1, 1). See glRasterPos.
GL_CURRENT_RASTER_DISTANCE: params returns one value, the distance from the eye to the current raster position. The initial value is 0. See glRasterPos.
GL_CURRENT_RASTER_INDEX: params returns one value, the color index of the current raster position. The initial value is 1. See glRasterPos.
GL_CURRENT_RASTER_POSITION: params returns four values: the x, y, z, and w components of the current raster position. x, y, and z are in window coordinates, and w is in clip coordinates. The initial value is (0, 0, 0, 1). See glRasterPos.
GL_CURRENT_RASTER_POSITION_VALID: params returns a single boolean value indicating whether the current raster position is valid. The initial value is GL_TRUE. See glRasterPos.
GL_CURRENT_RASTER_SECONDARY_COLOR: params returns four values: the red, green, blue, and alpha secondary color values of the current raster position. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (1, 1, 1, 1). See glRasterPos.
GL_CURRENT_RASTER_TEXTURE_COORDS: params returns four values: the s, t, r, and q texture coordinates of the current raster position. The initial value is (0, 0, 0, 1). See glRasterPos and glMultiTexCoord.
GL_CURRENT_SECONDARY_COLOR: params returns four values: the red, green, blue, and alpha values of the current secondary color. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0, 0, 0, 0). See glSecondaryColor.
GL_CURRENT_TEXTURE_COORDS: params returns four values: the s, t, r, and q current texture coordinates. The initial value is (0, 0, 0, 1). See glMultiTexCoord.
GL_DEPTH_BIAS: params returns one value, the depth bias factor used during pixel transfers. The initial value is 0. See glPixelTransfer.
GL_DEPTH_BITS: params returns one value, the number of bitplanes in the depth buffer.
GL_DEPTH_CLEAR_VALUE: params returns one value, the value that is used to clear the depth buffer. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is 1. See glClearDepth.
GL_DEPTH_FUNC: params returns one value, the symbolic constant that indicates the depth comparison function. The initial value is GL_LESS. See glDepthFunc.
GL_DEPTH_RANGE: params returns two values: the near and far mapping limits for the depth buffer. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0, 1). See glDepthRange.
GL_DEPTH_SCALE: params returns one value, the depth scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer.
GL_DEPTH_TEST: params returns a single boolean value indicating whether depth testing of fragments is enabled. The initial value is GL_FALSE. See glDepthFunc and glDepthRange.
GL_DEPTH_WRITEMASK: params returns a single boolean value indicating if the depth buffer is enabled for writing. The initial value is GL_TRUE. See glDepthMask.
GL_DITHER: params returns a single boolean value indicating whether dithering of fragment colors and indices is enabled. The initial value is GL_TRUE.
GL_DOUBLEBUFFER: params returns a single boolean value indicating whether double buffering is supported.
GL_DRAW_BUFFER: params returns one value, a symbolic constant indicating which buffers are being drawn to. See glDrawBuffer. The initial value is GL_BACK if there are back buffers, otherwise it is GL_FRONT.
GL_DRAW_BUFFERi: params returns one value, a symbolic constant indicating which buffers are being drawn to by the corresponding output color. See glDrawBuffers. The initial value of GL_DRAW_BUFFER0 is GL_BACK if there are back buffers, otherwise it is GL_FRONT. The initial values of draw buffers for all other output colors is GL_NONE.
GL_EDGE_FLAG: params returns a single boolean value indicating whether the current edge flag is GL_TRUE or GL_FALSE. The initial value is GL_TRUE. See glEdgeFlag.
GL_EDGE_FLAG_ARRAY: params returns a single boolean value indicating whether the edge flag array is enabled. The initial value is GL_FALSE. See glEdgeFlagPointer.
GL_EDGE_FLAG_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object associated with the edge flag array. This buffer object would have been bound to the target GL_ARRAY_BUFFER at the time of the most recent call to glEdgeFlagPointer. If no buffer object was bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_EDGE_FLAG_ARRAY_STRIDE: params returns one value, the byte offset between consecutive edge flags in the edge flag array. The initial value is 0. See glEdgeFlagPointer.
GL_ELEMENT_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object currently bound to the target GL_ELEMENT_ARRAY_BUFFER. If no buffer object is bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_FEEDBACK_BUFFER_SIZE: params returns one value, the size of the feedback buffer. See glFeedbackBuffer.
GL_FEEDBACK_BUFFER_TYPE: params returns one value, the type of the feedback buffer. See glFeedbackBuffer.
GL_FOG: params returns a single boolean value indicating whether fogging is enabled. The initial value is GL_FALSE. See glFog.
GL_FOG_COORD_ARRAY: params returns a single boolean value indicating whether the fog coordinate array is enabled. The initial value is GL_FALSE. See glFogCoordPointer.
GL_FOG_COORD_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object associated with the fog coordinate array. This buffer object would have been bound to the target GL_ARRAY_BUFFER at the time of the most recent call to glFogCoordPointer. If no buffer object was bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_FOG_COORD_ARRAY_STRIDE: params returns one value, the byte offset between consecutive fog coordinates in the fog coordinate array. The initial value is 0. See glFogCoordPointer.
GL_FOG_COORD_ARRAY_TYPE: params returns one value, the type of the fog coordinate array. The initial value is GL_FLOAT. See glFogCoordPointer.
GL_FOG_COORD_SRC: params returns one value, a symbolic constant indicating the source of the fog coordinate. The initial value is GL_FRAGMENT_DEPTH. See glFog.
GL_FOG_COLOR: params returns four values: the red, green, blue, and alpha components of the fog color. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0, 0, 0, 0). See glFog.
GL_FOG_DENSITY: params returns one value, the fog density parameter. The initial value is 1. See glFog.
GL_FOG_END: params returns one value, the end factor for the linear fog equation. The initial value is 1. See glFog.
GL_FOG_HINT: params returns one value, a symbolic constant indicating the mode of the fog hint. The initial value is GL_DONT_CARE. See glHint.
GL_FOG_INDEX: params returns one value, the fog color index. The initial value is 0. See glFog.
GL_FOG_MODE: params returns one value, a symbolic constant indicating which fog equation is selected. The initial value is GL_EXP. See glFog.
GL_FOG_START: params returns one value, the start factor for the linear fog equation. The initial value is 0. See glFog.
GL_FRAGMENT_SHADER_DERIVATIVE_HINT: params returns one value, a symbolic constant indicating the mode of the derivative accuracy hint for fragment shaders. The initial value is GL_DONT_CARE. See glHint.
GL_FRONT_FACE: params returns one value, a symbolic constant indicating whether clockwise or counterclockwise polygon winding is treated as front-facing. The initial value is GL_CCW. See glFrontFace.
GL_GENERATE_MIPMAP_HINT: params returns one value, a symbolic constant indicating the mode of the mipmap generation filtering hint. The initial value is GL_DONT_CARE. See glHint.
GL_GREEN_BIAS: params returns one value, the green bias factor used during pixel transfers. The initial value is 0.
GL_GREEN_BITS: params returns one value, the number of green bitplanes in each color buffer.
GL_GREEN_SCALE: params returns one value, the green scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer.
GL_HISTOGRAM: params returns a single boolean value indicating whether histogram is enabled. The initial value is GL_FALSE. See glHistogram.
GL_INDEX_ARRAY: params returns a single boolean value indicating whether the color index array is enabled. The initial value is GL_FALSE. See glIndexPointer.
GL_INDEX_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object associated with the color index array. This buffer object would have been bound to the target GL_ARRAY_BUFFER at the time of the most recent call to glIndexPointer. If no buffer object was bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_INDEX_ARRAY_STRIDE: params returns one value, the byte offset between consecutive color indexes in the color index array. The initial value is 0. See glIndexPointer.
GL_INDEX_ARRAY_TYPE: params returns one value, the data type of indexes in the color index array. The initial value is GL_FLOAT. See glIndexPointer.
GL_INDEX_BITS: params returns one value, the number of bitplanes in each color index buffer.
GL_INDEX_CLEAR_VALUE: params returns one value, the color index used to clear the color index buffers. The initial value is 0. See glClearIndex.
GL_INDEX_LOGIC_OP: params returns a single boolean value indicating whether a fragment’s index values are merged into the framebuffer using a logical operation. The initial value is GL_FALSE. See glLogicOp.
GL_INDEX_MODE: params returns a single boolean value indicating whether the GL is in color index mode (GL_TRUE) or RGBA mode (GL_FALSE).
GL_INDEX_OFFSET: params returns one value, the offset added to color and stencil indices during pixel transfers. The initial value is 0. See glPixelTransfer.
GL_INDEX_SHIFT: params returns one value, the amount that color and stencil indices are shifted during pixel transfers. The initial value is 0. See glPixelTransfer.
GL_INDEX_WRITEMASK: params returns one value, a mask indicating which bitplanes of each color index buffer can be written. The initial value is all 1’s. See glIndexMask.
GL_LIGHTi: params returns a single boolean value indicating whether the specified light is enabled. The initial value is GL_FALSE. See glLight and glLightModel.
GL_LIGHTING: params returns a single boolean value indicating whether lighting is enabled. The initial value is GL_FALSE. See glLightModel.
GL_LIGHT_MODEL_AMBIENT: params returns four values: the red, green, blue, and alpha components of the ambient intensity of the entire scene. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0.2, 0.2, 0.2, 1.0). See glLightModel.
GL_LIGHT_MODEL_COLOR_CONTROL: params returns single enumerated value indicating whether specular reflection calculations are separated from normal lighting computations. The initial value is GL_SINGLE_COLOR.
GL_LIGHT_MODEL_LOCAL_VIEWER: params returns a single boolean value indicating whether specular reflection calculations treat the viewer as being local to the scene. The initial value is GL_FALSE. See glLightModel.
GL_LIGHT_MODEL_TWO_SIDE: params returns a single boolean value indicating whether separate materials are used to compute lighting for front- and back-facing polygons. The initial value is GL_FALSE. See glLightModel.
GL_LINE_SMOOTH: params returns a single boolean value indicating whether antialiasing of lines is enabled. The initial value is GL_FALSE. See glLineWidth.
GL_LINE_SMOOTH_HINT: params returns one value, a symbolic constant indicating the mode of the line antialiasing hint. The initial value is GL_DONT_CARE. See glHint.
GL_LINE_STIPPLE: params returns a single boolean value indicating whether stippling of lines is enabled. The initial value is GL_FALSE. See glLineStipple.
GL_LINE_STIPPLE_PATTERN: params returns one value, the 16-bit line stipple pattern. The initial value is all 1’s. See glLineStipple.
GL_LINE_STIPPLE_REPEAT: params returns one value, the line stipple repeat factor. The initial value is 1. See glLineStipple.
GL_LINE_WIDTH: params returns one value, the line width as specified with glLineWidth. The initial value is 1.
GL_LINE_WIDTH_GRANULARITY: params returns one value, the width difference between adjacent supported widths for antialiased lines. See glLineWidth.
GL_LINE_WIDTH_RANGE: params returns two values: the smallest and largest supported widths for antialiased lines. See glLineWidth.
GL_LIST_BASE: params returns one value, the base offset added to all names in arrays presented to glCallLists. The initial value is 0. See glListBase.
GL_LIST_INDEX: params returns one value, the name of the display list currently under construction. 0 is returned if no display list is currently under construction. The initial value is 0. See glNewList.
GL_LIST_MODE: params returns one value, a symbolic constant indicating the construction mode of the display list currently under construction. The initial value is 0. See glNewList.
GL_LOGIC_OP_MODE: params returns one value, a symbolic constant indicating the selected logic operation mode. The initial value is GL_COPY. See glLogicOp.
GL_MAP1_COLOR_4: params returns a single boolean value indicating whether 1D evaluation generates colors. The initial value is GL_FALSE. See glMap1.
GL_MAP1_GRID_DOMAIN: params returns two values: the endpoints of the 1D map’s grid domain. The initial value is (0, 1). See glMapGrid.
GL_MAP1_GRID_SEGMENTS: params returns one value, the number of partitions in the 1D map’s grid domain. The initial value is 1. See glMapGrid.
GL_MAP1_INDEX: params returns a single boolean value indicating whether 1D evaluation generates color indices. The initial value is GL_FALSE. See glMap1.
GL_MAP1_NORMAL: params returns a single boolean value indicating whether 1D evaluation generates normals. The initial value is GL_FALSE. See glMap1.
GL_MAP1_TEXTURE_COORD_1: params returns a single boolean value indicating whether 1D evaluation generates 1D texture coordinates. The initial value is GL_FALSE. See glMap1.
GL_MAP1_TEXTURE_COORD_2: params returns a single boolean value indicating whether 1D evaluation generates 2D texture coordinates. The initial value is GL_FALSE. See glMap1.
GL_MAP1_TEXTURE_COORD_3: params returns a single boolean value indicating whether 1D evaluation generates 3D texture coordinates. The initial value is GL_FALSE. See glMap1.
GL_MAP1_TEXTURE_COORD_4: params returns a single boolean value indicating whether 1D evaluation generates 4D texture coordinates. The initial value is GL_FALSE. See glMap1.
GL_MAP1_VERTEX_3: params returns a single boolean value indicating whether 1D evaluation generates 3D vertex coordinates. The initial value is GL_FALSE. See glMap1.
GL_MAP1_VERTEX_4: params returns a single boolean value indicating whether 1D evaluation generates 4D vertex coordinates. The initial value is GL_FALSE. See glMap1.
GL_MAP2_COLOR_4: params returns a single boolean value indicating whether 2D evaluation generates colors. The initial value is GL_FALSE. See glMap2.
GL_MAP2_GRID_DOMAIN: params returns four values: the endpoints of the 2D map’s i and j grid domains. The initial value is (0,1; 0,1). See glMapGrid.
GL_MAP2_GRID_SEGMENTS: params returns two values: the number of partitions in the 2D map’s i and j grid domains. The initial value is (1,1). See glMapGrid.
GL_MAP2_INDEX: params returns a single boolean value indicating whether 2D evaluation generates color indices. The initial value is GL_FALSE. See glMap2.
GL_MAP2_NORMAL: params returns a single boolean value indicating whether 2D evaluation generates normals. The initial value is GL_FALSE. See glMap2.
GL_MAP2_TEXTURE_COORD_1: params returns a single boolean value indicating whether 2D evaluation generates 1D texture coordinates. The initial value is GL_FALSE. See glMap2.
GL_MAP2_TEXTURE_COORD_2: params returns a single boolean value indicating whether 2D evaluation generates 2D texture coordinates. The initial value is GL_FALSE. See glMap2.
GL_MAP2_TEXTURE_COORD_3: params returns a single boolean value indicating whether 2D evaluation generates 3D texture coordinates. The initial value is GL_FALSE. See glMap2.
GL_MAP2_TEXTURE_COORD_4: params returns a single boolean value indicating whether 2D evaluation generates 4D texture coordinates. The initial value is GL_FALSE. See glMap2.
GL_MAP2_VERTEX_3: params returns a single boolean value indicating whether 2D evaluation generates 3D vertex coordinates. The initial value is GL_FALSE. See glMap2.
GL_MAP2_VERTEX_4: params returns a single boolean value indicating whether 2D evaluation generates 4D vertex coordinates. The initial value is GL_FALSE. See glMap2.
GL_MAP_COLOR: params returns a single boolean value indicating if colors and color indices are to be replaced by table lookup during pixel transfers. The initial value is GL_FALSE. See glPixelTransfer.
GL_MAP_STENCIL: params returns a single boolean value indicating if stencil indices are to be replaced by table lookup during pixel transfers. The initial value is GL_FALSE. See glPixelTransfer.
GL_MATRIX_MODE: params returns one value, a symbolic constant indicating which matrix stack is currently the target of all matrix operations. The initial value is GL_MODELVIEW. See glMatrixMode.
GL_MAX_3D_TEXTURE_SIZE: params returns one value, a rough estimate of the largest 3D texture that the GL can handle. The value must be at least 16. If the GL version is 1.2 or greater, use GL_PROXY_TEXTURE_3D to determine if a texture is too large. See glTexImage3D.
GL_MAX_CLIENT_ATTRIB_STACK_DEPTH: params returns one value indicating the maximum supported depth of the client attribute stack. See glPushClientAttrib.
GL_MAX_ATTRIB_STACK_DEPTH: params returns one value, the maximum supported depth of the attribute stack. The value must be at least 16. See glPushAttrib.
GL_MAX_CLIP_PLANES: params returns one value, the maximum number of application-defined clipping planes. The value must be at least 6. See glClipPlane.
GL_MAX_COLOR_MATRIX_STACK_DEPTH: params returns one value, the maximum supported depth of the color matrix stack. The value must be at least 2. See glPushMatrix.
GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS: params returns one value, the maximum supported texture image units that can be used to access texture maps from the vertex shader and the fragment processor combined. If both the vertex shader and the fragment processing stage access the same texture image unit, then that counts as using two texture image units against this limit. The value must be at least 2. See glActiveTexture.
GL_MAX_CUBE_MAP_TEXTURE_SIZE: params returns one value. The value gives a rough estimate of the largest cube-map texture that the GL can handle. The value must be at least 16. If the GL version is 1.3 or greater, use GL_PROXY_TEXTURE_CUBE_MAP to determine if a texture is too large. See glTexImage2D.
GL_MAX_DRAW_BUFFERS: params returns one value, the maximum number of simultaneous output colors allowed from a fragment shader using the gl_FragData built-in array. The value must be at least 1. See glDrawBuffers.
GL_MAX_ELEMENTS_INDICES: params returns one value, the recommended maximum number of vertex array indices. See glDrawRangeElements.
GL_MAX_ELEMENTS_VERTICES: params returns one value, the recommended maximum number of vertex array vertices. See glDrawRangeElements.
GL_MAX_EVAL_ORDER: params returns one value, the maximum equation order supported by 1D and 2D evaluators. The value must be at least 8. See glMap1 and glMap2.
GL_MAX_FRAGMENT_UNIFORM_COMPONENTS: params returns one value, the maximum number of individual floating-point, integer, or boolean values that can be held in uniform variable storage for a fragment shader. The value must be at least 64. See glUniform.
GL_MAX_LIGHTS: params returns one value, the maximum number of lights. The value must be at least 8. See glLight.
GL_MAX_LIST_NESTING: params returns one value, the maximum recursion depth allowed during display-list traversal. The value must be at least 64. See glCallList.
GL_MAX_MODELVIEW_STACK_DEPTH: params returns one value, the maximum supported depth of the modelview matrix stack. The value must be at least 32. See glPushMatrix.
GL_MAX_NAME_STACK_DEPTH: params returns one value, the maximum supported depth of the selection name stack. The value must be at least 64. See glPushName.
GL_MAX_PIXEL_MAP_TABLE: params returns one value, the maximum supported size of a glPixelMap lookup table. The value must be at least 32. See glPixelMap.
GL_MAX_PROJECTION_STACK_DEPTH: params returns one value, the maximum supported depth of the projection matrix stack. The value must be at least 2. See glPushMatrix.
GL_MAX_TEXTURE_COORDS: params returns one value, the maximum number of texture coordinate sets available to vertex and fragment shaders. The value must be at least 2. See glActiveTexture and glClientActiveTexture.
GL_MAX_TEXTURE_IMAGE_UNITS: params returns one value, the maximum supported texture image units that can be used to access texture maps from the fragment shader. The value must be at least 2. See glActiveTexture.
GL_MAX_TEXTURE_LOD_BIAS: params returns one value, the maximum, absolute value of the texture level-of-detail bias. The value must be at least 4.
GL_MAX_TEXTURE_SIZE: params returns one value. The value gives a rough estimate of the largest texture that the GL can handle. The value must be at least 64. If the GL version is 1.1 or greater, use GL_PROXY_TEXTURE_1D or GL_PROXY_TEXTURE_2D to determine if a texture is too large. See glTexImage1D and glTexImage2D.
GL_MAX_TEXTURE_STACK_DEPTH: params returns one value, the maximum supported depth of the texture matrix stack. The value must be at least 2. See glPushMatrix.
GL_MAX_TEXTURE_UNITS: params returns a single value indicating the number of conventional texture units supported. Each conventional texture unit includes both a texture coordinate set and a texture image unit. Conventional texture units may be used for fixed-function (non-shader) rendering. The value must be at least 2. Additional texture coordinate sets and texture image units may be accessed from vertex and fragment shaders. See glActiveTexture and glClientActiveTexture.
GL_MAX_VARYING_FLOATS: params returns one value, the maximum number of interpolators available for processing varying variables used by vertex and fragment shaders. This value represents the number of individual floating-point values that can be interpolated; varying variables declared as vectors, matrices, and arrays will all consume multiple interpolators. The value must be at least 32.
GL_MAX_VERTEX_ATTRIBS: params returns one value, the maximum number of 4-component generic vertex attributes accessible to a vertex shader. The value must be at least 16. See glVertexAttrib.
GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS: params returns one value, the maximum supported texture image units that can be used to access texture maps from the vertex shader. The value may be 0. See glActiveTexture.
GL_MAX_VERTEX_UNIFORM_COMPONENTS: params returns one value, the maximum number of individual floating-point, integer, or boolean values that can be held in uniform variable storage for a vertex shader. The value must be at least 512. See glUniform.
GL_MAX_VIEWPORT_DIMS: params returns two values: the maximum supported width and height of the viewport. These must be at least as large as the visible dimensions of the display being rendered to. See glViewport.
GL_MINMAX: params returns a single boolean value indicating whether pixel minmax values are computed. The initial value is GL_FALSE. See glMinmax.
GL_MODELVIEW_MATRIX: params returns sixteen values: the modelview matrix on the top of the modelview matrix stack. Initially this matrix is the identity matrix. See glPushMatrix.
GL_MODELVIEW_STACK_DEPTH: params returns one value, the number of matrices on the modelview matrix stack. The initial value is 1. See glPushMatrix.
GL_NAME_STACK_DEPTH: params returns one value, the number of names on the selection name stack. The initial value is 0. See glPushName.
GL_NORMAL_ARRAY: params returns a single boolean value, indicating whether the normal array is enabled. The initial value is GL_FALSE. See glNormalPointer.
GL_NORMAL_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object associated with the normal array. This buffer object would have been bound to the target GL_ARRAY_BUFFER at the time of the most recent call to glNormalPointer. If no buffer object was bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_NORMAL_ARRAY_STRIDE: params returns one value, the byte offset between consecutive normals in the normal array. The initial value is 0. See glNormalPointer.
GL_NORMAL_ARRAY_TYPE: params returns one value, the data type of each coordinate in the normal array. The initial value is GL_FLOAT. See glNormalPointer.
GL_NORMALIZE: params returns a single boolean value indicating whether normals are automatically scaled to unit length after they have been transformed to eye coordinates. The initial value is GL_FALSE. See glNormal.
GL_NUM_COMPRESSED_TEXTURE_FORMATS: params returns a single integer value indicating the number of available compressed texture formats. The minimum value is 0. See glCompressedTexImage2D.
GL_PACK_ALIGNMENT: params returns one value, the byte alignment used for writing pixel data to memory. The initial value is 4. See glPixelStore.
GL_PACK_IMAGE_HEIGHT: params returns one value, the image height used for writing pixel data to memory. The initial value is 0. See glPixelStore.
GL_PACK_LSB_FIRST: params returns a single boolean value indicating whether single-bit pixels being written to memory are written first to the least significant bit of each unsigned byte. The initial value is GL_FALSE. See glPixelStore.
GL_PACK_ROW_LENGTH: params returns one value, the row length used for writing pixel data to memory. The initial value is 0. See glPixelStore.
GL_PACK_SKIP_IMAGES: params returns one value, the number of pixel images skipped before the first pixel is written into memory. The initial value is 0. See glPixelStore.
GL_PACK_SKIP_PIXELS: params returns one value, the number of pixel locations skipped before the first pixel is written into memory. The initial value is 0. See glPixelStore.
GL_PACK_SKIP_ROWS: params returns one value, the number of rows of pixel locations skipped before the first pixel is written into memory. The initial value is 0. See glPixelStore.
GL_PACK_SWAP_BYTES: params returns a single boolean value indicating whether the bytes of two-byte and four-byte pixel indices and components are swapped before being written to memory. The initial value is GL_FALSE. See glPixelStore.
GL_PERSPECTIVE_CORRECTION_HINT: params returns one value, a symbolic constant indicating the mode of the perspective correction hint. The initial value is GL_DONT_CARE. See glHint.
GL_PIXEL_MAP_A_TO_A_SIZE: params returns one value, the size of the alpha-to-alpha pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_MAP_B_TO_B_SIZE: params returns one value, the size of the blue-to-blue pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_MAP_G_TO_G_SIZE: params returns one value, the size of the green-to-green pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_A_SIZE: params returns one value, the size of the index-to-alpha pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_B_SIZE: params returns one value, the size of the index-to-blue pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_G_SIZE: params returns one value, the size of the index-to-green pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_I_SIZE: params returns one value, the size of the index-to-index pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_R_SIZE: params returns one value, the size of the index-to-red pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_MAP_R_TO_R_SIZE: params returns one value, the size of the red-to-red pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_MAP_S_TO_S_SIZE: params returns one value, the size of the stencil-to-stencil pixel translation table. The initial value is 1. See glPixelMap.
GL_PIXEL_PACK_BUFFER_BINDING: params returns a single value, the name of the buffer object currently bound to the target GL_PIXEL_PACK_BUFFER. If no buffer object is bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_PIXEL_UNPACK_BUFFER_BINDING: params returns a single value, the name of the buffer object currently bound to the target GL_PIXEL_UNPACK_BUFFER. If no buffer object is bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_POINT_DISTANCE_ATTENUATION: params returns three values, the coefficients for computing the attenuation value for points. See glPointParameter.
GL_POINT_FADE_THRESHOLD_SIZE: params returns one value, the point size threshold for determining the point size. See glPointParameter.
GL_POINT_SIZE: params returns one value, the point size as specified by glPointSize. The initial value is 1.
GL_POINT_SIZE_GRANULARITY: params returns one value, the size difference between adjacent supported sizes for antialiased points. See glPointSize.
GL_POINT_SIZE_MAX: params returns one value, the upper bound for the attenuated point sizes. The initial value is 0.0. See glPointParameter.
GL_POINT_SIZE_MIN: params returns one value, the lower bound for the attenuated point sizes. The initial value is 1.0. See glPointParameter.
GL_POINT_SIZE_RANGE: params returns two values: the smallest and largest supported sizes for antialiased points. The smallest size must be at most 1, and the largest size must be at least 1. See glPointSize.
GL_POINT_SMOOTH: params returns a single boolean value indicating whether antialiasing of points is enabled. The initial value is GL_FALSE. See glPointSize.
GL_POINT_SMOOTH_HINT: params returns one value, a symbolic constant indicating the mode of the point antialiasing hint. The initial value is GL_DONT_CARE. See glHint.
GL_POINT_SPRITE: params returns a single boolean value indicating whether point sprite is enabled. The initial value is GL_FALSE.
GL_POLYGON_MODE: params returns two values: symbolic constants indicating whether front-facing and back-facing polygons are rasterized as points, lines, or filled polygons. The initial value is GL_FILL. See glPolygonMode.
GL_POLYGON_OFFSET_FACTOR: params returns one value, the scaling factor used to determine the variable offset that is added to the depth value of each fragment generated when a polygon is rasterized. The initial value is 0. See glPolygonOffset.
GL_POLYGON_OFFSET_UNITS: params returns one value. This value is multiplied by an implementation-specific value and then added to the depth value of each fragment generated when a polygon is rasterized. The initial value is 0. See glPolygonOffset.
GL_POLYGON_OFFSET_FILL: params returns a single boolean value indicating whether polygon offset is enabled for polygons in fill mode. The initial value is GL_FALSE. See glPolygonOffset.
GL_POLYGON_OFFSET_LINE: params returns a single boolean value indicating whether polygon offset is enabled for polygons in line mode. The initial value is GL_FALSE. See glPolygonOffset.
GL_POLYGON_OFFSET_POINT: params returns a single boolean value indicating whether polygon offset is enabled for polygons in point mode. The initial value is GL_FALSE. See glPolygonOffset.
GL_POLYGON_SMOOTH: params returns a single boolean value indicating whether antialiasing of polygons is enabled. The initial value is GL_FALSE. See glPolygonMode.
GL_POLYGON_SMOOTH_HINT: params returns one value, a symbolic constant indicating the mode of the polygon antialiasing hint. The initial value is GL_DONT_CARE. See glHint.
GL_POLYGON_STIPPLE: params returns a single boolean value indicating whether polygon stippling is enabled. The initial value is GL_FALSE. See glPolygonStipple.
GL_POST_COLOR_MATRIX_COLOR_TABLE: params returns a single boolean value indicating whether post color matrix transformation lookup is enabled. The initial value is GL_FALSE. See glColorTable.
GL_POST_COLOR_MATRIX_RED_BIAS: params returns one value, the red bias factor applied to RGBA fragments after color matrix transformations. The initial value is 0. See glPixelTransfer.
GL_POST_COLOR_MATRIX_GREEN_BIAS: params returns one value, the green bias factor applied to RGBA fragments after color matrix transformations. The initial value is 0. See glPixelTransfer
GL_POST_COLOR_MATRIX_BLUE_BIAS: params returns one value, the blue bias factor applied to RGBA fragments after color matrix transformations. The initial value is 0. See glPixelTransfer.
GL_POST_COLOR_MATRIX_ALPHA_BIAS: params returns one value, the alpha bias factor applied to RGBA fragments after color matrix transformations. The initial value is 0. See glPixelTransfer.
GL_POST_COLOR_MATRIX_RED_SCALE: params returns one value, the red scale factor applied to RGBA fragments after color matrix transformations. The initial value is 1. See glPixelTransfer.
GL_POST_COLOR_MATRIX_GREEN_SCALE: params returns one value, the green scale factor applied to RGBA fragments after color matrix transformations. The initial value is 1. See glPixelTransfer.
GL_POST_COLOR_MATRIX_BLUE_SCALE: params returns one value, the blue scale factor applied to RGBA fragments after color matrix transformations. The initial value is 1. See glPixelTransfer.
GL_POST_COLOR_MATRIX_ALPHA_SCALE: params returns one value, the alpha scale factor applied to RGBA fragments after color matrix transformations. The initial value is 1. See glPixelTransfer.
GL_POST_CONVOLUTION_COLOR_TABLE: params returns a single boolean value indicating whether post convolution lookup is enabled. The initial value is GL_FALSE. See glColorTable.
GL_POST_CONVOLUTION_RED_BIAS: params returns one value, the red bias factor applied to RGBA fragments after convolution. The initial value is 0. See glPixelTransfer.
GL_POST_CONVOLUTION_GREEN_BIAS: params returns one value, the green bias factor applied to RGBA fragments after convolution. The initial value is 0. See glPixelTransfer.
GL_POST_CONVOLUTION_BLUE_BIAS: params returns one value, the blue bias factor applied to RGBA fragments after convolution. The initial value is 0. See glPixelTransfer.
GL_POST_CONVOLUTION_ALPHA_BIAS: params returns one value, the alpha bias factor applied to RGBA fragments after convolution. The initial value is 0. See glPixelTransfer.
GL_POST_CONVOLUTION_RED_SCALE: params returns one value, the red scale factor applied to RGBA fragments after convolution. The initial value is 1. See glPixelTransfer.
GL_POST_CONVOLUTION_GREEN_SCALE: params returns one value, the green scale factor applied to RGBA fragments after convolution. The initial value is 1. See glPixelTransfer.
GL_POST_CONVOLUTION_BLUE_SCALE: params returns one value, the blue scale factor applied to RGBA fragments after convolution. The initial value is 1. See glPixelTransfer.
GL_POST_CONVOLUTION_ALPHA_SCALE: params returns one value, the alpha scale factor applied to RGBA fragments after convolution. The initial value is 1. See glPixelTransfer.
GL_PROJECTION_MATRIX: params returns sixteen values: the projection matrix on the top of the projection matrix stack. Initially this matrix is the identity matrix. See glPushMatrix.
GL_PROJECTION_STACK_DEPTH: params returns one value, the number of matrices on the projection matrix stack. The initial value is 1. See glPushMatrix.
GL_READ_BUFFER: params returns one value, a symbolic constant indicating which color buffer is selected for reading. The initial value is GL_BACK if there is a back buffer, otherwise it is GL_FRONT. See glReadPixels and glAccum.
GL_RED_BIAS: params returns one value, the red bias factor used during pixel transfers. The initial value is 0.
GL_RED_BITS: params returns one value, the number of red bitplanes in each color buffer.
GL_RED_SCALE: params returns one value, the red scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer.
GL_RENDER_MODE: params returns one value, a symbolic constant indicating whether the GL is in render, select, or feedback mode. The initial value is GL_RENDER. See glRenderMode.
GL_RESCALE_NORMAL: params returns single boolean value indicating whether normal rescaling is enabled. See glEnable.
GL_RGBA_MODE: params returns a single boolean value indicating whether the GL is in RGBA mode (true) or color index mode (false). See glColor.
GL_SAMPLE_BUFFERS: params returns a single integer value indicating the number of sample buffers associated with the framebuffer. See glSampleCoverage.
GL_SAMPLE_COVERAGE_VALUE: params returns a single positive floating-point value indicating the current sample coverage value. See glSampleCoverage.
GL_SAMPLE_COVERAGE_INVERT: params returns a single boolean value indicating if the temporary coverage value should be inverted. See glSampleCoverage.
GL_SAMPLES: params returns a single integer value indicating the coverage mask size. See glSampleCoverage.
GL_SCISSOR_BOX: params returns four values: the x and y window coordinates of the scissor box, followed by its width and height. Initially the x and y window coordinates are both 0 and the width and height are set to the size of the window. See glScissor.
GL_SCISSOR_TEST: params returns a single boolean value indicating whether scissoring is enabled. The initial value is GL_FALSE. See glScissor.
GL_SECONDARY_COLOR_ARRAY: params returns a single boolean value indicating whether the secondary color array is enabled. The initial value is GL_FALSE. See glSecondaryColorPointer.
GL_SECONDARY_COLOR_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object associated with the secondary color array. This buffer object would have been bound to the target GL_ARRAY_BUFFER at the time of the most recent call to glSecondaryColorPointer. If no buffer object was bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_SECONDARY_COLOR_ARRAY_SIZE: params returns one value, the number of components per color in the secondary color array. The initial value is 3. See glSecondaryColorPointer.
GL_SECONDARY_COLOR_ARRAY_STRIDE: params returns one value, the byte offset between consecutive colors in the secondary color array. The initial value is 0. See glSecondaryColorPointer.
GL_SECONDARY_COLOR_ARRAY_TYPE: params returns one value, the data type of each component in the secondary color array. The initial value is GL_FLOAT. See glSecondaryColorPointer.
GL_SELECTION_BUFFER_SIZE: params return one value, the size of the selection buffer. See glSelectBuffer.
GL_SEPARABLE_2D: params returns a single boolean value indicating whether 2D separable convolution is enabled. The initial value is GL_FALSE. See glSeparableFilter2D.
GL_SHADE_MODEL: params returns one value, a symbolic constant indicating whether the shading mode is flat or smooth. The initial value is GL_SMOOTH. See glShadeModel.
GL_SMOOTH_LINE_WIDTH_RANGE: params returns two values, the smallest and largest supported widths for antialiased lines. See glLineWidth.
GL_SMOOTH_LINE_WIDTH_GRANULARITY: params returns one value, the granularity of widths for antialiased lines. See glLineWidth.
GL_SMOOTH_POINT_SIZE_RANGE: params returns two values, the smallest and largest supported widths for antialiased points. See glPointSize.
GL_SMOOTH_POINT_SIZE_GRANULARITY: params returns one value, the granularity of sizes for antialiased points. See glPointSize.
GL_STENCIL_BACK_FAIL: params returns one value, a symbolic constant indicating what action is taken for back-facing polygons when the stencil test fails. The initial value is GL_KEEP. See glStencilOpSeparate.
GL_STENCIL_BACK_FUNC: params returns one value, a symbolic constant indicating what function is used for back-facing polygons to compare the stencil reference value with the stencil buffer value. The initial value is GL_ALWAYS. See glStencilFuncSeparate.
GL_STENCIL_BACK_PASS_DEPTH_FAIL: params returns one value, a symbolic constant indicating what action is taken for back-facing polygons when the stencil test passes, but the depth test fails. The initial value is GL_KEEP. See glStencilOpSeparate.
GL_STENCIL_BACK_PASS_DEPTH_PASS: params returns one value, a symbolic constant indicating what action is taken for back-facing polygons when the stencil test passes and the depth test passes. The initial value is GL_KEEP. See glStencilOpSeparate.
GL_STENCIL_BACK_REF: params returns one value, the reference value that is compared with the contents of the stencil buffer for back-facing polygons. The initial value is 0. See glStencilFuncSeparate.
GL_STENCIL_BACK_VALUE_MASK: params returns one value, the mask that is used for back-facing polygons to mask both the stencil reference value and the stencil buffer value before they are compared. The initial value is all 1’s. See glStencilFuncSeparate.
GL_STENCIL_BACK_WRITEMASK: params returns one value, the mask that controls writing of the stencil bitplanes for back-facing polygons. The initial value is all 1’s. See glStencilMaskSeparate.
GL_STENCIL_BITS: params returns one value, the number of bitplanes in the stencil buffer.
GL_STENCIL_CLEAR_VALUE: params returns one value, the index to which the stencil bitplanes are cleared. The initial value is 0. See glClearStencil.
GL_STENCIL_FAIL: params returns one value, a symbolic constant indicating what action is taken when the stencil test fails. The initial value is GL_KEEP. See glStencilOp. If the GL version is 2.0 or greater, this stencil state only affects non-polygons and front-facing polygons. Back-facing polygons use separate stencil state. See glStencilOpSeparate.
GL_STENCIL_FUNC: params returns one value, a symbolic constant indicating what function is used to compare the stencil reference value with the stencil buffer value. The initial value is GL_ALWAYS. See glStencilFunc. If the GL version is 2.0 or greater, this stencil state only affects non-polygons and front-facing polygons. Back-facing polygons use separate stencil state. See glStencilFuncSeparate.
GL_STENCIL_PASS_DEPTH_FAIL: params returns one value, a symbolic constant indicating what action is taken when the stencil test passes, but the depth test fails. The initial value is GL_KEEP. See glStencilOp. If the GL version is 2.0 or greater, this stencil state only affects non-polygons and front-facing polygons. Back-facing polygons use separate stencil state. See glStencilOpSeparate.
GL_STENCIL_PASS_DEPTH_PASS: params returns one value, a symbolic constant indicating what action is taken when the stencil test passes and the depth test passes. The initial value is GL_KEEP. See glStencilOp. If the GL version is 2.0 or greater, this stencil state only affects non-polygons and front-facing polygons. Back-facing polygons use separate stencil state. See glStencilOpSeparate.
GL_STENCIL_REF: params returns one value, the reference value that is compared with the contents of the stencil buffer. The initial value is 0. See glStencilFunc. If the GL version is 2.0 or greater, this stencil state only affects non-polygons and front-facing polygons. Back-facing polygons use separate stencil state. See glStencilFuncSeparate.
GL_STENCIL_TEST: params returns a single boolean value indicating whether stencil testing of fragments is enabled. The initial value is GL_FALSE. See glStencilFunc and glStencilOp.
GL_STENCIL_VALUE_MASK: params returns one value, the mask that is used to mask both the stencil reference value and the stencil buffer value before they are compared. The initial value is all 1’s. See glStencilFunc. If the GL version is 2.0 or greater, this stencil state only affects non-polygons and front-facing polygons. Back-facing polygons use separate stencil state. See glStencilFuncSeparate.
GL_STENCIL_WRITEMASK: params returns one value, the mask that controls writing of the stencil bitplanes. The initial value is all 1’s. See glStencilMask. If the GL version is 2.0 or greater, this stencil state only affects non-polygons and front-facing polygons. Back-facing polygons use separate stencil state. See glStencilMaskSeparate.
GL_STEREO: params returns a single boolean value indicating whether stereo buffers (left and right) are supported.
GL_SUBPIXEL_BITS: params returns one value, an estimate of the number of bits of subpixel resolution that are used to position rasterized geometry in window coordinates. The value must be at least 4.
GL_TEXTURE_1D: params returns a single boolean value indicating whether 1D texture mapping is enabled. The initial value is GL_FALSE. See glTexImage1D.
GL_TEXTURE_BINDING_1D: params returns a single value, the name of the texture currently bound to the target GL_TEXTURE_1D. The initial value is 0. See glBindTexture.
GL_TEXTURE_2D: params returns a single boolean value indicating whether 2D texture mapping is enabled. The initial value is GL_FALSE. See glTexImage2D.
GL_TEXTURE_BINDING_2D: params returns a single value, the name of the texture currently bound to the target GL_TEXTURE_2D. The initial value is 0. See glBindTexture.
GL_TEXTURE_3D: params returns a single boolean value indicating whether 3D texture mapping is enabled. The initial value is GL_FALSE. See glTexImage3D.
GL_TEXTURE_BINDING_3D: params returns a single value, the name of the texture currently bound to the target GL_TEXTURE_3D. The initial value is 0. See glBindTexture.
GL_TEXTURE_BINDING_CUBE_MAP: params returns a single value, the name of the texture currently bound to the target GL_TEXTURE_CUBE_MAP. The initial value is 0. See glBindTexture.
GL_TEXTURE_COMPRESSION_HINT: params returns a single value indicating the mode of the texture compression hint. The initial value is GL_DONT_CARE.
GL_TEXTURE_COORD_ARRAY: params returns a single boolean value indicating whether the texture coordinate array is enabled. The initial value is GL_FALSE. See glTexCoordPointer.
GL_TEXTURE_COORD_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object associated with the texture coordinate array. This buffer object would have been bound to the target GL_ARRAY_BUFFER at the time of the most recent call to glTexCoordPointer. If no buffer object was bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_TEXTURE_COORD_ARRAY_SIZE: params returns one value, the number of coordinates per element in the texture coordinate array. The initial value is 4. See glTexCoordPointer.
GL_TEXTURE_COORD_ARRAY_STRIDE: params returns one value, the byte offset between consecutive elements in the texture coordinate array. The initial value is 0. See glTexCoordPointer.
GL_TEXTURE_COORD_ARRAY_TYPE: params returns one value, the data type of the coordinates in the texture coordinate array. The initial value is GL_FLOAT. See glTexCoordPointer.
GL_TEXTURE_CUBE_MAP: params returns a single boolean value indicating whether cube-mapped texture mapping is enabled. The initial value is GL_FALSE. See glTexImage2D.
GL_TEXTURE_GEN_Q: params returns a single boolean value indicating whether automatic generation of the q texture coordinate is enabled. The initial value is GL_FALSE. See glTexGen.
GL_TEXTURE_GEN_R: params returns a single boolean value indicating whether automatic generation of the r texture coordinate is enabled. The initial value is GL_FALSE. See glTexGen.
GL_TEXTURE_GEN_S: params returns a single boolean value indicating whether automatic generation of the S texture coordinate is enabled. The initial value is GL_FALSE. See glTexGen.
GL_TEXTURE_GEN_T: params returns a single boolean value indicating whether automatic generation of the T texture coordinate is enabled. The initial value is GL_FALSE. See glTexGen.
GL_TEXTURE_MATRIX: params returns sixteen values: the texture matrix on the top of the texture matrix stack. Initially this matrix is the identity matrix. See glPushMatrix.
GL_TEXTURE_STACK_DEPTH: params returns one value, the number of matrices on the texture matrix stack. The initial value is 1. See glPushMatrix.
GL_TRANSPOSE_COLOR_MATRIX: params returns 16 values, the elements of the color matrix in row-major order. See glLoadTransposeMatrix.
GL_TRANSPOSE_MODELVIEW_MATRIX: params returns 16 values, the elements of the modelview matrix in row-major order. See glLoadTransposeMatrix.
GL_TRANSPOSE_PROJECTION_MATRIX: params returns 16 values, the elements of the projection matrix in row-major order. See glLoadTransposeMatrix.
GL_TRANSPOSE_TEXTURE_MATRIX: params returns 16 values, the elements of the texture matrix in row-major order. See glLoadTransposeMatrix.
GL_UNPACK_ALIGNMENT: params returns one value, the byte alignment used for reading pixel data from memory. The initial value is 4. See glPixelStore.
GL_UNPACK_IMAGE_HEIGHT: params returns one value, the image height used for reading pixel data from memory. The initial is 0. See glPixelStore.
GL_UNPACK_LSB_FIRST: params returns a single boolean value indicating whether single-bit pixels being read from memory are read first from the least significant bit of each unsigned byte. The initial value is GL_FALSE. See glPixelStore.
GL_UNPACK_ROW_LENGTH: params returns one value, the row length used for reading pixel data from memory. The initial value is 0. See glPixelStore.
GL_UNPACK_SKIP_IMAGES: params returns one value, the number of pixel images skipped before the first pixel is read from memory. The initial value is 0. See glPixelStore.
GL_UNPACK_SKIP_PIXELS: params returns one value, the number of pixel locations skipped before the first pixel is read from memory. The initial value is 0. See glPixelStore.
GL_UNPACK_SKIP_ROWS: params returns one value, the number of rows of pixel locations skipped before the first pixel is read from memory. The initial value is 0. See glPixelStore.
GL_UNPACK_SWAP_BYTES: params returns a single boolean value indicating whether the bytes of two-byte and four-byte pixel indices and components are swapped after being read from memory. The initial value is GL_FALSE. See glPixelStore.
GL_VERTEX_ARRAY: params returns a single boolean value indicating whether the vertex array is enabled. The initial value is GL_FALSE. See glVertexPointer.
GL_VERTEX_ARRAY_BUFFER_BINDING: params returns a single value, the name of the buffer object associated with the vertex array. This buffer object would have been bound to the target GL_ARRAY_BUFFER at the time of the most recent call to glVertexPointer. If no buffer object was bound to this target, 0 is returned. The initial value is 0. See glBindBuffer.
GL_VERTEX_ARRAY_SIZE: params returns one value, the number of coordinates per vertex in the vertex array. The initial value is 4. See glVertexPointer.
GL_VERTEX_ARRAY_STRIDE: params returns one value, the byte offset between consecutive vertices in the vertex array. The initial value is 0. See glVertexPointer.
GL_VERTEX_ARRAY_TYPE: params returns one value, the data type of each coordinate in the vertex array. The initial value is GL_FLOAT. See glVertexPointer.
GL_VERTEX_PROGRAM_POINT_SIZE: params returns a single boolean value indicating whether vertex program point size mode is enabled. If enabled, and a vertex shader is active, then the point size is taken from the shader built-in gl_PointSize. If disabled, and a vertex shader is active, then the point size is taken from the point state as specified by glPointSize. The initial value is GL_FALSE.
GL_VERTEX_PROGRAM_TWO_SIDE: params returns a single boolean value indicating whether vertex program two-sided color mode is enabled. If enabled, and a vertex shader is active, then the GL chooses the back color output for back-facing polygons, and the front color output for non-polygons and front-facing polygons. If disabled, and a vertex shader is active, then the front color output is always selected. The initial value is GL_FALSE.
GL_VIEWPORT: params returns four values: the x and y window coordinates of the viewport, followed by its width and height. Initially the x and y window coordinates are both set to 0, and the width and height are set to the width and height of the window into which the GL will do its rendering. See glViewport.
GL_ZOOM_X: params returns one value, the x pixel zoom factor. The initial value is 1. See glPixelZoom.
GL_ZOOM_Y: params returns one value, the y pixel zoom factor. The initial value is 1. See glPixelZoom.

Many of the boolean parameters can also be queried more easily using glIsEnabled.

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_OPERATION is generated if glGet is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glHint target mode

Specify implementation-specific hints.

target: Specifies a symbolic constant indicating the behavior to be controlled. GL_FOG_HINT, GL_GENERATE_MIPMAP_HINT, GL_LINE_SMOOTH_HINT, GL_PERSPECTIVE_CORRECTION_HINT, GL_POINT_SMOOTH_HINT, GL_POLYGON_SMOOTH_HINT, GL_TEXTURE_COMPRESSION_HINT, and GL_FRAGMENT_SHADER_DERIVATIVE_HINT are accepted.
mode: Specifies a symbolic constant indicating the desired behavior. GL_FASTEST, GL_NICEST, and GL_DONT_CARE are accepted.

Certain aspects of GL behavior, when there is room for interpretation, can be controlled with hints. A hint is specified with two arguments. target is a symbolic constant indicating the behavior to be controlled, and mode is another symbolic constant indicating the desired behavior. The initial value for each target is GL_DONT_CARE. mode can be one of the following:

GL_FASTEST: The most efficient option should be chosen.
GL_NICEST: The most correct, or highest quality, option should be chosen.
GL_DONT_CARE: No preference.

Though the implementation aspects that can be hinted are well defined, the interpretation of the hints depends on the implementation. The hint aspects that can be specified with target, along with suggested semantics, are as follows:

GL_FOG_HINT: Indicates the accuracy of fog calculation. If per-pixel fog calculation is not efficiently supported by the GL implementation, hinting GL_DONT_CARE or GL_FASTEST can result in per-vertex calculation of fog effects.
GL_FRAGMENT_SHADER_DERIVATIVE_HINT: Indicates the accuracy of the derivative calculation for the GL shading language fragment processing built-in functions: dFdx, dFdy, and fwidth.
GL_GENERATE_MIPMAP_HINT: Indicates the quality of filtering when generating mipmap images.
GL_LINE_SMOOTH_HINT: Indicates the sampling quality of antialiased lines. If a larger filter function is applied, hinting GL_NICEST can result in more pixel fragments being generated during rasterization.
GL_PERSPECTIVE_CORRECTION_HINT: Indicates the quality of color, texture coordinate, and fog coordinate interpolation. If perspective-corrected parameter interpolation is not efficiently supported by the GL implementation, hinting GL_DONT_CARE or GL_FASTEST can result in simple linear interpolation of colors and/or texture coordinates.
GL_POINT_SMOOTH_HINT: Indicates the sampling quality of antialiased points. If a larger filter function is applied, hinting GL_NICEST can result in more pixel fragments being generated during rasterization.
GL_POLYGON_SMOOTH_HINT: Indicates the sampling quality of antialiased polygons. Hinting GL_NICEST can result in more pixel fragments being generated during rasterization, if a larger filter function is applied.
GL_TEXTURE_COMPRESSION_HINT: Indicates the quality and performance of the compressing texture images. Hinting GL_FASTEST indicates that texture images should be compressed as quickly as possible, while GL_NICEST indicates that texture images should be compressed with as little image quality loss as possible. GL_NICEST should be selected if the texture is to be retrieved by glGetCompressedTexImage for reuse.

GL_INVALID_ENUM is generated if either target or mode is not an accepted value.

GL_INVALID_OPERATION is generated if glHint is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glHistogram target width internalformat sink

Define histogram table.

target: The histogram whose parameters are to be set. Must be one of GL_HISTOGRAM or GL_PROXY_HISTOGRAM.
width: The number of entries in the histogram table. Must be a power of 2.
internalformat: The format of entries in the histogram table. Must be one of GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
sink: If GL_TRUE, pixels will be consumed by the histogramming process and no drawing or texture loading will take place. If GL_FALSE, pixels will proceed to the minmax process after histogramming.

When GL_HISTOGRAM is enabled, RGBA color components are converted to histogram table indices by clamping to the range [0,1], multiplying by the width of the histogram table, and rounding to the nearest integer. The table entries selected by the RGBA indices are then incremented. (If the internal format of the histogram table includes luminance, then the index derived from the R color component determines the luminance table entry to be incremented.) If a histogram table entry is incremented beyond its maximum value, then its value becomes undefined. (This is not an error.)

Histogramming is performed only for RGBA pixels (though these may be specified originally as color indices and converted to RGBA by index table lookup). Histogramming is enabled with glEnable and disabled with glDisable.

When target is GL_HISTOGRAM, glHistogram redefines the current histogram table to have width entries of the format specified by internalformat. The entries are indexed 0 through width-1, and all entries are initialized to zero. The values in the previous histogram table, if any, are lost. If sink is GL_TRUE, then pixels are discarded after histogramming; no further processing of the pixels takes place, and no drawing, texture loading, or pixel readback will result.

When target is GL_PROXY_HISTOGRAM, glHistogram computes all state information as if the histogram table were to be redefined, but does not actually define the new table. If the requested histogram table is too large to be supported, then the state information will be set to zero. This provides a way to determine if a histogram table with the given parameters can be supported.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_VALUE is generated if width is less than zero or is not a power of 2.

GL_INVALID_ENUM is generated if internalformat is not one of the allowable values.

GL_TABLE_TOO_LARGE is generated if target is GL_HISTOGRAM and the histogram table specified is too large for the implementation.

GL_INVALID_OPERATION is generated if glHistogram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glIndexMask mask

Control the writing of individual bits in the color index buffers.

mask: Specifies a bit mask to enable and disable the writing of individual bits in the color index buffers. Initially, the mask is all 1’s.

glIndexMask controls the writing of individual bits in the color index buffers. The least significant n bits of mask, where n is the number of bits in a color index buffer, specify a mask. Where a 1 (one) appears in the mask, it’s possible to write to the corresponding bit in the color index buffer (or buffers). Where a 0 (zero) appears, the corresponding bit is write-protected.

This mask is used only in color index mode, and it affects only the buffers currently selected for writing (see glDrawBuffer). Initially, all bits are enabled for writing.

GL_INVALID_OPERATION is generated if glIndexMask is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glIndexPointer type stride pointer

Define an array of color indexes.

type: Specifies the data type of each color index in the array. Symbolic constants GL_UNSIGNED_BYTE, GL_SHORT, GL_INT, GL_FLOAT, and GL_DOUBLE are accepted. The initial value is GL_FLOAT.
stride: Specifies the byte offset between consecutive color indexes. If stride is 0, the color indexes are understood to be tightly packed in the array. The initial value is 0.
pointer: Specifies a pointer to the first index in the array. The initial value is 0.

glIndexPointer specifies the location and data format of an array of color indexes to use when rendering. type specifies the data type of each color index and stride specifies the byte stride from one color index to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays.

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer) while a color index array is specified, pointer is treated as a byte offset into the buffer object’s data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as color index vertex array client-side state (GL_INDEX_ARRAY_BUFFER_BINDING).

When a color index array is specified, type, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable the color index array, call glEnableClientState and glDisableClientState with the argument GL_INDEX_ARRAY. If enabled, the color index array is used when glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, glDrawRangeElements, or glArrayElement is called.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if stride is negative.

Function: void glIndexs c

Function: void glIndexi c

Function: void glIndexf c

Function: void glIndexd c

Function: void glIndexub c

Function: void glIndexsv c

Function: void glIndexiv c

Function: void glIndexfv c

Function: void glIndexdv c

Function: void glIndexubv c

Set the current color index.

c: Specifies the new value for the current color index.

glIndex updates the current (single-valued) color index. It takes one argument, the new value for the current color index.

The current index is stored as a floating-point value. Integer values are converted directly to floating-point values, with no special mapping. The initial value is 1.

Index values outside the representable range of the color index buffer are not clamped. However, before an index is dithered (if enabled) and written to the frame buffer, it is converted to fixed-point format. Any bits in the integer portion of the resulting fixed-point value that do not correspond to bits in the frame buffer are masked out.

Function: void glInitNames

Initialize the name stack.

The name stack is used during selection mode to allow sets of rendering commands to be uniquely identified. It consists of an ordered set of unsigned integers. glInitNames causes the name stack to be initialized to its default empty state.

The name stack is always empty while the render mode is not GL_SELECT. Calls to glInitNames while the render mode is not GL_SELECT are ignored.

GL_INVALID_OPERATION is generated if glInitNames is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glInterleavedArrays format stride pointer

Simultaneously specify and enable several interleaved arrays.

format: Specifies the type of array to enable. Symbolic constants GL_V2F, GL_V3F, GL_C4UB_V2F, GL_C4UB_V3F, GL_C3F_V3F, GL_N3F_V3F, GL_C4F_N3F_V3F, GL_T2F_V3F, GL_T4F_V4F, GL_T2F_C4UB_V3F, GL_T2F_C3F_V3F, GL_T2F_N3F_V3F, GL_T2F_C4F_N3F_V3F, and GL_T4F_C4F_N3F_V4F are accepted.
stride: Specifies the offset in bytes between each aggregate array element.

glInterleavedArrays lets you specify and enable individual color, normal, texture and vertex arrays whose elements are part of a larger aggregate array element. For some implementations, this is more efficient than specifying the arrays separately.

If stride is 0, the aggregate elements are stored consecutively. Otherwise, stride bytes occur between the beginning of one aggregate array element and the beginning of the next aggregate array element.

format serves as a “key” describing the extraction of individual arrays from the aggregate array. If format contains a T, then texture coordinates are extracted from the interleaved array. If C is present, color values are extracted. If N is present, normal coordinates are extracted. Vertex coordinates are always extracted.

The digits 2, 3, and 4 denote how many values are extracted. F indicates that values are extracted as floating-point values. Colors may also be extracted as 4 unsigned bytes if 4UB follows the C. If a color is extracted as 4 unsigned bytes, the vertex array element which follows is located at the first possible floating-point aligned address.

GL_INVALID_ENUM is generated if format is not an accepted value.

GL_INVALID_VALUE is generated if stride is negative.

Function: GLboolean glIsBuffer buffer

Determine if a name corresponds to a buffer object.

buffer: Specifies a value that may be the name of a buffer object.

glIsBuffer returns GL_TRUE if buffer is currently the name of a buffer object. If buffer is zero, or is a non-zero value that is not currently the name of a buffer object, or if an error occurs, glIsBuffer returns GL_FALSE.

A name returned by glGenBuffers, but not yet associated with a buffer object by calling glBindBuffer, is not the name of a buffer object.

GL_INVALID_OPERATION is generated if glIsBuffer is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLboolean glIsEnabled cap

Test whether a capability is enabled.

cap: Specifies a symbolic constant indicating a GL capability.

glIsEnabled returns GL_TRUE if cap is an enabled capability and returns GL_FALSE otherwise. Initially all capabilities except GL_DITHER are disabled; GL_DITHER is initially enabled.

The following capabilities are accepted for cap:

Constant: See
GL_ALPHA_TEST: glAlphaFunc
GL_AUTO_NORMAL: glEvalCoord
GL_BLEND: glBlendFunc, glLogicOp
GL_CLIP_PLANEi: glClipPlane
GL_COLOR_ARRAY: glColorPointer
GL_COLOR_LOGIC_OP: glLogicOp
GL_COLOR_MATERIAL: glColorMaterial
GL_COLOR_SUM: glSecondaryColor
GL_COLOR_TABLE: glColorTable
GL_CONVOLUTION_1D: glConvolutionFilter1D
GL_CONVOLUTION_2D: glConvolutionFilter2D
GL_CULL_FACE: glCullFace
GL_DEPTH_TEST: glDepthFunc, glDepthRange
GL_DITHER: glEnable
GL_EDGE_FLAG_ARRAY: glEdgeFlagPointer
GL_FOG: glFog
GL_FOG_COORD_ARRAY: glFogCoordPointer
GL_HISTOGRAM: glHistogram
GL_INDEX_ARRAY: glIndexPointer
GL_INDEX_LOGIC_OP: glLogicOp
GL_LIGHTi: glLightModel, glLight
GL_LIGHTING: glMaterial, glLightModel, glLight
GL_LINE_SMOOTH: glLineWidth
GL_LINE_STIPPLE: glLineStipple
GL_MAP1_COLOR_4: glMap1
GL_MAP1_INDEX: glMap1
GL_MAP1_NORMAL: glMap1
GL_MAP1_TEXTURE_COORD_1: glMap1
GL_MAP1_TEXTURE_COORD_2: glMap1
GL_MAP1_TEXTURE_COORD_3: glMap1
GL_MAP1_TEXTURE_COORD_4: glMap1
GL_MAP2_COLOR_4: glMap2
GL_MAP2_INDEX: glMap2
GL_MAP2_NORMAL: glMap2
GL_MAP2_TEXTURE_COORD_1: glMap2
GL_MAP2_TEXTURE_COORD_2: glMap2
GL_MAP2_TEXTURE_COORD_3: glMap2
GL_MAP2_TEXTURE_COORD_4: glMap2
GL_MAP2_VERTEX_3: glMap2
GL_MAP2_VERTEX_4: glMap2
GL_MINMAX: glMinmax
GL_MULTISAMPLE: glSampleCoverage
GL_NORMAL_ARRAY: glNormalPointer
GL_NORMALIZE: glNormal
GL_POINT_SMOOTH: glPointSize
GL_POINT_SPRITE: glEnable
GL_POLYGON_SMOOTH: glPolygonMode
GL_POLYGON_OFFSET_FILL: glPolygonOffset
GL_POLYGON_OFFSET_LINE: glPolygonOffset
GL_POLYGON_OFFSET_POINT: glPolygonOffset
GL_POLYGON_STIPPLE: glPolygonStipple
GL_POST_COLOR_MATRIX_COLOR_TABLE: glColorTable
GL_POST_CONVOLUTION_COLOR_TABLE: glColorTable
GL_RESCALE_NORMAL: glNormal
GL_SAMPLE_ALPHA_TO_COVERAGE: glSampleCoverage
GL_SAMPLE_ALPHA_TO_ONE: glSampleCoverage
GL_SAMPLE_COVERAGE: glSampleCoverage
GL_SCISSOR_TEST: glScissor
GL_SECONDARY_COLOR_ARRAY: glSecondaryColorPointer
GL_SEPARABLE_2D: glSeparableFilter2D
GL_STENCIL_TEST: glStencilFunc, glStencilOp
GL_TEXTURE_1D: glTexImage1D
GL_TEXTURE_2D: glTexImage2D
GL_TEXTURE_3D: glTexImage3D
GL_TEXTURE_COORD_ARRAY: glTexCoordPointer
GL_TEXTURE_CUBE_MAP: glTexImage2D
GL_TEXTURE_GEN_Q: glTexGen
GL_TEXTURE_GEN_R: glTexGen
GL_TEXTURE_GEN_S: glTexGen
GL_TEXTURE_GEN_T: glTexGen
GL_VERTEX_ARRAY: glVertexPointer
GL_VERTEX_PROGRAM_POINT_SIZE: glEnable
GL_VERTEX_PROGRAM_TWO_SIDE: glEnable

GL_INVALID_ENUM is generated if cap is not an accepted value.

GL_INVALID_OPERATION is generated if glIsEnabled is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLboolean glIsList list

Determine if a name corresponds to a display list.

list: Specifies a potential display list name.

glIsList returns GL_TRUE if list is the name of a display list and returns GL_FALSE if it is not, or if an error occurs.

A name returned by glGenLists, but not yet associated with a display list by calling glNewList, is not the name of a display list.

GL_INVALID_OPERATION is generated if glIsList is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLboolean glIsProgram program

Determines if a name corresponds to a program object.

program: Specifies a potential program object.

glIsProgram returns GL_TRUE if program is the name of a program object previously created with glCreateProgram and not yet deleted with glDeleteProgram. If program is zero or a non-zero value that is not the name of a program object, or if an error occurs, glIsProgram returns GL_FALSE.

GL_INVALID_OPERATION is generated if glIsProgram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLboolean glIsQuery id

Determine if a name corresponds to a query object.

id: Specifies a value that may be the name of a query object.

glIsQuery returns GL_TRUE if id is currently the name of a query object. If id is zero, or is a non-zero value that is not currently the name of a query object, or if an error occurs, glIsQuery returns GL_FALSE.

A name returned by glGenQueries, but not yet associated with a query object by calling glBeginQuery, is not the name of a query object.

GL_INVALID_OPERATION is generated if glIsQuery is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLboolean glIsShader shader

Determines if a name corresponds to a shader object.

shader: Specifies a potential shader object.

glIsShader returns GL_TRUE if shader is the name of a shader object previously created with glCreateShader and not yet deleted with glDeleteShader. If shader is zero or a non-zero value that is not the name of a shader object, or if an error occurs, glIsShader returns GL_FALSE.

GL_INVALID_OPERATION is generated if glIsShader is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLboolean glIsTexture texture

Determine if a name corresponds to a texture.

texture: Specifies a value that may be the name of a texture.

glIsTexture returns GL_TRUE if texture is currently the name of a texture. If texture is zero, or is a non-zero value that is not currently the name of a texture, or if an error occurs, glIsTexture returns GL_FALSE.

A name returned by glGenTextures, but not yet associated with a texture by calling glBindTexture, is not the name of a texture.

GL_INVALID_OPERATION is generated if glIsTexture is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLightModelf pname param

Function: void glLightModeli pname param

Function: void glLightModelfv pname params

Function: void glLightModeliv pname params

Set the lighting model parameters.

pname: Specifies a single-valued lighting model parameter. GL_LIGHT_MODEL_LOCAL_VIEWER, GL_LIGHT_MODEL_COLOR_CONTROL, and GL_LIGHT_MODEL_TWO_SIDE are accepted.
param: Specifies the value that param will be set to.

glLightModel sets the lighting model parameter. pname names a parameter and params gives the new value. There are three lighting model parameters:

GL_LIGHT_MODEL_AMBIENT: params contains four integer or floating-point values that specify the ambient RGBA intensity of the entire scene. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial ambient scene intensity is (0.2, 0.2, 0.2, 1.0).
GL_LIGHT_MODEL_COLOR_CONTROL: params must be either GL_SEPARATE_SPECULAR_COLOR or GL_SINGLE_COLOR. GL_SINGLE_COLOR specifies that a single color is generated from the lighting computation for a vertex. GL_SEPARATE_SPECULAR_COLOR specifies that the specular color computation of lighting be stored separately from the remainder of the lighting computation. The specular color is summed into the generated fragment’s color after the application of texture mapping (if enabled). The initial value is GL_SINGLE_COLOR.
GL_LIGHT_MODEL_LOCAL_VIEWER: params is a single integer or floating-point value that specifies how specular reflection angles are computed. If params is 0 (or 0.0), specular reflection angles take the view direction to be parallel to and in the direction of the -z axis, regardless of the location of the vertex in eye coordinates. Otherwise, specular reflections are computed from the origin of the eye coordinate system. The initial value is 0.
GL_LIGHT_MODEL_TWO_SIDE: params is a single integer or floating-point value that specifies whether one- or two-sided lighting calculations are done for polygons. It has no effect on the lighting calculations for points, lines, or bitmaps. If params is 0 (or 0.0), one-sided lighting is specified, and only the front material parameters are used in the lighting equation. Otherwise, two-sided lighting is specified. In this case, vertices of back-facing polygons are lighted using the back material parameters and have their normals reversed before the lighting equation is evaluated. Vertices of front-facing polygons are always lighted using the front material parameters, with no change to their normals. The initial value is 0.

In RGBA mode, the lighted color of a vertex is the sum of the material emission intensity, the product of the material ambient reflectance and the lighting model full-scene ambient intensity, and the contribution of each enabled light source. Each light source contributes the sum of three terms: ambient, diffuse, and specular. The ambient light source contribution is the product of the material ambient reflectance and the light’s ambient intensity. The diffuse light source contribution is the product of the material diffuse reflectance, the light’s diffuse intensity, and the dot product of the vertex’s normal with the normalized vector from the vertex to the light source. The specular light source contribution is the product of the material specular reflectance, the light’s specular intensity, and the dot product of the normalized vertex-to-eye and vertex-to-light vectors, raised to the power of the shininess of the material. All three light source contributions are attenuated equally based on the distance from the vertex to the light source and on light source direction, spread exponent, and spread cutoff angle. All dot products are replaced with 0 if they evaluate to a negative value.

The alpha component of the resulting lighted color is set to the alpha value of the material diffuse reflectance.

In color index mode, the value of the lighted index of a vertex ranges from the ambient to the specular values passed to glMaterial using GL_COLOR_INDEXES. Diffuse and specular coefficients, computed with a (.30, .59, .11) weighting of the lights’ colors, the shininess of the material, and the same reflection and attenuation equations as in the RGBA case, determine how much above ambient the resulting index is.

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_ENUM is generated if pname is GL_LIGHT_MODEL_COLOR_CONTROL and params is not one of GL_SINGLE_COLOR or GL_SEPARATE_SPECULAR_COLOR.

GL_INVALID_OPERATION is generated if glLightModel is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLightf light pname param

Function: void glLighti light pname param

Function: void glLightfv light pname params

Function: void glLightiv light pname params

Set light source parameters.

light: Specifies a light. The number of lights depends on the implementation, but at least eight lights are supported. They are identified by symbolic names of the form GL_LIGHTi, where i ranges from 0 to the value of GL_MAX_LIGHTS - 1.
pname: Specifies a single-valued light source parameter for light. GL_SPOT_EXPONENT, GL_SPOT_CUTOFF, GL_CONSTANT_ATTENUATION, GL_LINEAR_ATTENUATION, and GL_QUADRATIC_ATTENUATION are accepted.
param: Specifies the value that parameter pname of light source light will be set to.

glLight sets the values of individual light source parameters. light names the light and is a symbolic name of the form GL_LIGHTi, where i ranges from 0 to the value of GL_MAX_LIGHTS - 1. pname specifies one of ten light source parameters, again by symbolic name. params is either a single value or a pointer to an array that contains the new values.

To enable and disable lighting calculation, call glEnable and glDisable with argument GL_LIGHTING. Lighting is initially disabled. When it is enabled, light sources that are enabled contribute to the lighting calculation. Light source i is enabled and disabled using glEnable and glDisable with argument GL_LIGHTi.

The ten light parameters are as follows:

GL_AMBIENT

params contains four integer or floating-point values that specify the ambient RGBA intensity of the light. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial ambient light intensity is (0, 0, 0, 1).

GL_DIFFUSE

params contains four integer or floating-point values that specify the diffuse RGBA intensity of the light. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial value for GL_LIGHT0 is (1, 1, 1, 1); for other lights, the initial value is (0, 0, 0, 1).

GL_SPECULAR

params contains four integer or floating-point values that specify the specular RGBA intensity of the light. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial value for GL_LIGHT0 is (1, 1, 1, 1); for other lights, the initial value is (0, 0, 0, 1).

GL_POSITION

params contains four integer or floating-point values that specify the position of the light in homogeneous object coordinates. Both integer and floating-point values are mapped directly. Neither integer nor floating-point values are clamped.

The position is transformed by the modelview matrix when glLight is called (just as if it were a point), and it is stored in eye coordinates. If the w component of the position is 0, the light is treated as a directional source. Diffuse and specular lighting calculations take the light’s direction, but not its actual position, into account, and attenuation is disabled. Otherwise, diffuse and specular lighting calculations are based on the actual location of the light in eye coordinates, and attenuation is enabled. The initial position is (0, 0, 1, 0); thus, the initial light source is directional, parallel to, and in the direction of the -z axis.

GL_SPOT_DIRECTION

params contains three integer or floating-point values that specify the direction of the light in homogeneous object coordinates. Both integer and floating-point values are mapped directly. Neither integer nor floating-point values are clamped.

The spot direction is transformed by the upper 3x3 of the modelview matrix when glLight is called, and it is stored in eye coordinates. It is significant only when GL_SPOT_CUTOFF is not 180, which it is initially. The initial direction is (0,0-1).

GL_SPOT_EXPONENT

params is a single integer or floating-point value that specifies the intensity distribution of the light. Integer and floating-point values are mapped directly. Only values in the range [0,128] are accepted.

Effective light intensity is attenuated by the cosine of the angle between the direction of the light and the direction from the light to the vertex being lighted, raised to the power of the spot exponent. Thus, higher spot exponents result in a more focused light source, regardless of the spot cutoff angle (see GL_SPOT_CUTOFF, next paragraph). The initial spot exponent is 0, resulting in uniform light distribution.

GL_SPOT_CUTOFF

params is a single integer or floating-point value that specifies the maximum spread angle of a light source. Integer and floating-point values are mapped directly. Only values in the range [0,90] and the special value 180 are accepted. If the angle between the direction of the light and the direction from the light to the vertex being lighted is greater than the spot cutoff angle, the light is completely masked. Otherwise, its intensity is controlled by the spot exponent and the attenuation factors. The initial spot cutoff is 180, resulting in uniform light distribution.

GL_CONSTANT_ATTENUATION

GL_LINEAR_ATTENUATION

GL_QUADRATIC_ATTENUATION

params is a single integer or floating-point value that specifies one of the three light attenuation factors. Integer and floating-point values are mapped directly. Only nonnegative values are accepted. If the light is positional, rather than directional, its intensity is attenuated by the reciprocal of the sum of the constant factor, the linear factor times the distance between the light and the vertex being lighted, and the quadratic factor times the square of the same distance. The initial attenuation factors are (1, 0, 0), resulting in no attenuation.

GL_INVALID_ENUM is generated if either light or pname is not an accepted value.

GL_INVALID_VALUE is generated if a spot exponent value is specified outside the range [0,128], or if spot cutoff is specified outside the range [0,90] (except for the special value 180), or if a negative attenuation factor is specified.

GL_INVALID_OPERATION is generated if glLight is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLineStipple factor pattern

Specify the line stipple pattern.

factor: Specifies a multiplier for each bit in the line stipple pattern. If factor is 3, for example, each bit in the pattern is used three times before the next bit in the pattern is used. factor is clamped to the range [1, 256] and defaults to 1.
pattern: Specifies a 16-bit integer whose bit pattern determines which fragments of a line will be drawn when the line is rasterized. Bit zero is used first; the default pattern is all 1’s.

Line stippling masks out certain fragments produced by rasterization; those fragments will not be drawn. The masking is achieved by using three parameters: the 16-bit line stipple pattern pattern, the repeat count factor, and an integer stipple counter s.

Counter s is reset to 0 whenever glBegin is called and before each line segment of a glBegin(GL_LINES)/glEnd sequence is generated. It is incremented after each fragment of a unit width aliased line segment is generated or after each i fragments of an i width line segment are generated. The i fragments associated with count s are masked out if

pattern bit (s/factor,)%16

is 0, otherwise these fragments are sent to the frame buffer. Bit zero of pattern is the least significant bit.

Antialiased lines are treated as a sequence of 1Ãwidth rectangles for purposes of stippling. Whether rectangle s is rasterized or not depends on the fragment rule described for aliased lines, counting rectangles rather than groups of fragments.

To enable and disable line stippling, call glEnable and glDisable with argument GL_LINE_STIPPLE. When enabled, the line stipple pattern is applied as described above. When disabled, it is as if the pattern were all 1’s. Initially, line stippling is disabled.

GL_INVALID_OPERATION is generated if glLineStipple is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLineWidth width

Specify the width of rasterized lines.

width: Specifies the width of rasterized lines. The initial value is 1.

glLineWidth specifies the rasterized width of both aliased and antialiased lines. Using a line width other than 1 has different effects, depending on whether line antialiasing is enabled. To enable and disable line antialiasing, call glEnable and glDisable with argument GL_LINE_SMOOTH. Line antialiasing is initially disabled.

If line antialiasing is disabled, the actual width is determined by rounding the supplied width to the nearest integer. (If the rounding results in the value 0, it is as if the line width were 1.) If â£Îx,â£>=â£Îy,â£, i pixels are filled in each column that is rasterized, where i is the rounded value of width. Otherwise, i pixels are filled in each row that is rasterized.

If antialiasing is enabled, line rasterization produces a fragment for each pixel square that intersects the region lying within the rectangle having width equal to the current line width, length equal to the actual length of the line, and centered on the mathematical line segment. The coverage value for each fragment is the window coordinate area of the intersection of the rectangular region with the corresponding pixel square. This value is saved and used in the final rasterization step.

Not all widths can be supported when line antialiasing is enabled. If an unsupported width is requested, the nearest supported width is used. Only width 1 is guaranteed to be supported; others depend on the implementation. Likewise, there is a range for aliased line widths as well. To query the range of supported widths and the size difference between supported widths within the range, call glGet with arguments GL_ALIASED_LINE_WIDTH_RANGE, GL_SMOOTH_LINE_WIDTH_RANGE, and GL_SMOOTH_LINE_WIDTH_GRANULARITY.

GL_INVALID_VALUE is generated if width is less than or equal to 0.

GL_INVALID_OPERATION is generated if glLineWidth is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLinkProgram program

Links a program object.

program: Specifies the handle of the program object to be linked.

glLinkProgram links the program object specified by program. If any shader objects of type GL_VERTEX_SHADER are attached to program, they will be used to create an executable that will run on the programmable vertex processor. If any shader objects of type GL_FRAGMENT_SHADER are attached to program, they will be used to create an executable that will run on the programmable fragment processor.

The status of the link operation will be stored as part of the program object’s state. This value will be set to GL_TRUE if the program object was linked without errors and is ready for use, and GL_FALSE otherwise. It can be queried by calling glGetProgram with arguments program and GL_LINK_STATUS.

As a result of a successful link operation, all active user-defined uniform variables belonging to program will be initialized to 0, and each of the program object’s active uniform variables will be assigned a location that can be queried by calling glGetUniformLocation. Also, any active user-defined attribute variables that have not been bound to a generic vertex attribute index will be bound to one at this time.

Linking of a program object can fail for a number of reasons as specified in the OpenGL Shading Language Specification. The following lists some of the conditions that will cause a link error.

The number of active attribute variables supported by the implementation has been exceeded.
The storage limit for uniform variables has been exceeded.
The number of active uniform variables supported by the implementation has been exceeded.
The main function is missing for the vertex shader or the fragment shader.
A varying variable actually used in the fragment shader is not declared in the same way (or is not declared at all) in the vertex shader.
A reference to a function or variable name is unresolved.
A shared global is declared with two different types or two different initial values.
One or more of the attached shader objects has not been successfully compiled.
Binding a generic attribute matrix caused some rows of the matrix to fall outside the allowed maximum of GL_MAX_VERTEX_ATTRIBS.
Not enough contiguous vertex attribute slots could be found to bind attribute matrices.

When a program object has been successfully linked, the program object can be made part of current state by calling glUseProgram. Whether or not the link operation was successful, the program object’s information log will be overwritten. The information log can be retrieved by calling glGetProgramInfoLog.

glLinkProgram will also install the generated executables as part of the current rendering state if the link operation was successful and the specified program object is already currently in use as a result of a previous call to glUseProgram. If the program object currently in use is relinked unsuccessfully, its link status will be set to GL_FALSE , but the executables and associated state will remain part of the current state until a subsequent call to glUseProgram removes it from use. After it is removed from use, it cannot be made part of current state until it has been successfully relinked.

If program contains shader objects of type GL_VERTEX_SHADER but does not contain shader objects of type GL_FRAGMENT_SHADER, the vertex shader will be linked against the implicit interface for fixed functionality fragment processing. Similarly, if program contains shader objects of type GL_FRAGMENT_SHADER but it does not contain shader objects of type GL_VERTEX_SHADER, the fragment shader will be linked against the implicit interface for fixed functionality vertex processing.

The program object’s information log is updated and the program is generated at the time of the link operation. After the link operation, applications are free to modify attached shader objects, compile attached shader objects, detach shader objects, delete shader objects, and attach additional shader objects. None of these operations affects the information log or the program that is part of the program object.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_OPERATION is generated if glLinkProgram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glListBase base

Set the display-list base for .

base: Specifies an integer offset that will be added to glCallLists offsets to generate display-list names. The initial value is 0.

glCallLists specifies an array of offsets. Display-list names are generated by adding base to each offset. Names that reference valid display lists are executed; the others are ignored.

GL_INVALID_OPERATION is generated if glListBase is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLoadIdentity

Replace the current matrix with the identity matrix.

glLoadIdentity replaces the current matrix with the identity matrix. It is semantically equivalent to calling glLoadMatrix with the identity matrix

((1 0 0 0), (0 1 0 0), (0 0 1 0), (0 0 0 1),,)

but in some cases it is more efficient.

GL_INVALID_OPERATION is generated if glLoadIdentity is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLoadMatrixd m

Function: void glLoadMatrixf m

Replace the current matrix with the specified matrix.

m: Specifies a pointer to 16 consecutive values, which are used as the elements of a 4Ã4 column-major matrix.

glLoadMatrix replaces the current matrix with the one whose elements are specified by m. The current matrix is the projection matrix, modelview matrix, or texture matrix, depending on the current matrix mode (see glMatrixMode).

The current matrix, M, defines a transformation of coordinates. For instance, assume M refers to the modelview matrix. If v=(vâ¡[0,],vâ¡[1,]vâ¡[2,]vâ¡[3,]) is the set of object coordinates of a vertex, and m points to an array of 16 single- or double-precision floating-point values m={mâ¡[0,],mâ¡[1,]...mâ¡[15,]}, then the modelview transformation Mâ¡(v,) does the following:

Mâ¡(v,)=((mâ¡[0,] mâ¡[4,] mâ¡[8,] mâ¡[12,]), (mâ¡[1,] mâ¡[5,] mâ¡[9,] mâ¡[13,]), (mâ¡[2,] mâ¡[6,] mâ¡[10,] mâ¡[14,]), (mâ¡[3,] mâ¡[7,] mâ¡[11,] mâ¡[15,]),)Ã((vâ¡[0,]), (vâ¡[1,]), (vâ¡[2,]), (vâ¡[3,]),)

Projection and texture transformations are similarly defined.

GL_INVALID_OPERATION is generated if glLoadMatrix is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLoadName name

Load a name onto the name stack.

name: Specifies a name that will replace the top value on the name stack.

The name stack is used during selection mode to allow sets of rendering commands to be uniquely identified. It consists of an ordered set of unsigned integers and is initially empty.

glLoadName causes name to replace the value on the top of the name stack.

The name stack is always empty while the render mode is not GL_SELECT. Calls to glLoadName while the render mode is not GL_SELECT are ignored.

GL_INVALID_OPERATION is generated if glLoadName is called while the name stack is empty.

GL_INVALID_OPERATION is generated if glLoadName is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLoadTransposeMatrixd m

Function: void glLoadTransposeMatrixf m

Replace the current matrix with the specified row-major ordered matrix.

m: Specifies a pointer to 16 consecutive values, which are used as the elements of a 4Ã4 row-major matrix.

glLoadTransposeMatrix replaces the current matrix with the one whose elements are specified by m. The current matrix is the projection matrix, modelview matrix, or texture matrix, depending on the current matrix mode (see glMatrixMode).

Mâ¡(v,)=((mâ¡[0,] mâ¡[1,] mâ¡[2,] mâ¡[3,]), (mâ¡[4,] mâ¡[5,] mâ¡[6,] mâ¡[7,]), (mâ¡[8,] mâ¡[9,] mâ¡[10,] mâ¡[11,]), (mâ¡[12,] mâ¡[13,] mâ¡[14,] mâ¡[15,]),)Ã((vâ¡[0,]), (vâ¡[1,]), (vâ¡[2,]), (vâ¡[3,]),)

Projection and texture transformations are similarly defined.

Calling glLoadTransposeMatrix with matrix M is identical in operation to glLoadMatrix with M^T, where T represents the transpose.

GL_INVALID_OPERATION is generated if glLoadTransposeMatrix is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glLogicOp opcode

Specify a logical pixel operation for color index rendering.

opcode: Specifies a symbolic constant that selects a logical operation. The following symbols are accepted: GL_CLEAR, GL_SET, GL_COPY, GL_COPY_INVERTED, GL_NOOP, GL_INVERT, GL_AND, GL_NAND, GL_OR, GL_NOR, GL_XOR, GL_EQUIV, GL_AND_REVERSE, GL_AND_INVERTED, GL_OR_REVERSE, and GL_OR_INVERTED. The initial value is GL_COPY.

glLogicOp specifies a logical operation that, when enabled, is applied between the incoming color index or RGBA color and the color index or RGBA color at the corresponding location in the frame buffer. To enable or disable the logical operation, call glEnable and glDisable using the symbolic constant GL_COLOR_LOGIC_OP for RGBA mode or GL_INDEX_LOGIC_OP for color index mode. The initial value is disabled for both operations.

Opcode: Resulting Operation
GL_CLEAR: 0
GL_SET: 1
GL_COPY: s
GL_COPY_INVERTED: ~s
GL_NOOP: d
GL_INVERT: ~d
GL_AND: s & d
GL_NAND: ~(s & d)
GL_OR: s | d
GL_NOR: ~(s | d)
GL_XOR: s ^ d
GL_EQUIV: ~(s ^ d)
GL_AND_REVERSE: s & ~d
GL_AND_INVERTED: ~s & d
GL_OR_REVERSE: s | ~d
GL_OR_INVERTED: ~s | d

opcode is a symbolic constant chosen from the list above. In the explanation of the logical operations, s represents the incoming color index and d represents the index in the frame buffer. Standard C-language operators are used. As these bitwise operators suggest, the logical operation is applied independently to each bit pair of the source and destination indices or colors.

GL_INVALID_ENUM is generated if opcode is not an accepted value.

GL_INVALID_OPERATION is generated if glLogicOp is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glMap1f target u1 u2 stride order points

Function: void glMap1d target u1 u2 stride order points

Define a one-dimensional evaluator.

target: Specifies the kind of values that are generated by the evaluator. Symbolic constants GL_MAP1_VERTEX_3, GL_MAP1_VERTEX_4, GL_MAP1_INDEX, GL_MAP1_COLOR_4, GL_MAP1_NORMAL, GL_MAP1_TEXTURE_COORD_1, GL_MAP1_TEXTURE_COORD_2, GL_MAP1_TEXTURE_COORD_3, and GL_MAP1_TEXTURE_COORD_4 are accepted.
u1
u2: Specify a linear mapping of u, as presented to glEvalCoord1, to u^, the variable that is evaluated by the equations specified by this command.
stride: Specifies the number of floats or doubles between the beginning of one control point and the beginning of the next one in the data structure referenced in points. This allows control points to be embedded in arbitrary data structures. The only constraint is that the values for a particular control point must occupy contiguous memory locations.
order: Specifies the number of control points. Must be positive.
points: Specifies a pointer to the array of control points.

Evaluators provide a way to use polynomial or rational polynomial mapping to produce vertices, normals, texture coordinates, and colors. The values produced by an evaluator are sent to further stages of GL processing just as if they had been presented using glVertex, glNormal, glTexCoord, and glColor commands, except that the generated values do not update the current normal, texture coordinates, or color.

All polynomial or rational polynomial splines of any degree (up to the maximum degree supported by the GL implementation) can be described using evaluators. These include almost all splines used in computer graphics: B-splines, Bezier curves, Hermite splines, and so on.

Evaluators define curves based on Bernstein polynomials. Define pâ¡(u^,) as

pâ¡(u^,)=Î£i=0nB_i,^nâ¡(u^,)â¢R_i

where R_i is a control point and B_i,^nâ¡(u^,) is the ith Bernstein polynomial of degree n (order = n+1):

B_i,^nâ¡(u^,)=((n), (i),,)â¢u^,^iâ¢(1-u^,)^n-i,,

Recall that

0^0==1 and ((n), (0),,)==1

glMap1 is used to define the basis and to specify what kind of values are produced. Once defined, a map can be enabled and disabled by calling glEnable and glDisable with the map name, one of the nine predefined values for target described below. glEvalCoord1 evaluates the one-dimensional maps that are enabled. When glEvalCoord1 presents a value u, the Bernstein functions are evaluated using u^, where u^=u-u1,/u2-u1,

target is a symbolic constant that indicates what kind of control points are provided in points, and what output is generated when the map is evaluated. It can assume one of nine predefined values:

GL_MAP1_VERTEX_3: Each control point is three floating-point values representing x, y, and z. Internal glVertex3 commands are generated when the map is evaluated.
GL_MAP1_VERTEX_4: Each control point is four floating-point values representing x, y, z, and w. Internal glVertex4 commands are generated when the map is evaluated.
GL_MAP1_INDEX: Each control point is a single floating-point value representing a color index. Internal glIndex commands are generated when the map is evaluated but the current index is not updated with the value of these glIndex commands.
GL_MAP1_COLOR_4: Each control point is four floating-point values representing red, green, blue, and alpha. Internal glColor4 commands are generated when the map is evaluated but the current color is not updated with the value of these glColor4 commands.
GL_MAP1_NORMAL: Each control point is three floating-point values representing the x, y, and z components of a normal vector. Internal glNormal commands are generated when the map is evaluated but the current normal is not updated with the value of these glNormal commands.
GL_MAP1_TEXTURE_COORD_1: Each control point is a single floating-point value representing the s texture coordinate. Internal glTexCoord1 commands are generated when the map is evaluated but the current texture coordinates are not updated with the value of these glTexCoord commands.
GL_MAP1_TEXTURE_COORD_2: Each control point is two floating-point values representing the s and t texture coordinates. Internal glTexCoord2 commands are generated when the map is evaluated but the current texture coordinates are not updated with the value of these glTexCoord commands.
GL_MAP1_TEXTURE_COORD_3: Each control point is three floating-point values representing the s, t, and r texture coordinates. Internal glTexCoord3 commands are generated when the map is evaluated but the current texture coordinates are not updated with the value of these glTexCoord commands.
GL_MAP1_TEXTURE_COORD_4: Each control point is four floating-point values representing the s, t, r, and q texture coordinates. Internal glTexCoord4 commands are generated when the map is evaluated but the current texture coordinates are not updated with the value of these glTexCoord commands.

stride, order, and points define the array addressing for accessing the control points. points is the location of the first control point, which occupies one, two, three, or four contiguous memory locations, depending on which map is being defined. order is the number of control points in the array. stride specifies how many float or double locations to advance the internal memory pointer to reach the next control point.

GL_INVALID_ENUM is generated if target is not an accepted value.

GL_INVALID_VALUE is generated if u1 is equal to u2.

GL_INVALID_VALUE is generated if stride is less than the number of values in a control point.

GL_INVALID_VALUE is generated if order is less than 1 or greater than the return value of GL_MAX_EVAL_ORDER.

GL_INVALID_OPERATION is generated if glMap1 is executed between the execution of glBegin and the corresponding execution of glEnd.

GL_INVALID_OPERATION is generated if glMap1 is called and the value of GL_ACTIVE_TEXTURE is not GL_TEXTURE0.

Function: void glMap2f target u1 u2 ustride uorder v1 v2 vstride vorder points

Function: void glMap2d target u1 u2 ustride uorder v1 v2 vstride vorder points

Define a two-dimensional evaluator.

target: Specifies the kind of values that are generated by the evaluator. Symbolic constants GL_MAP2_VERTEX_3, GL_MAP2_VERTEX_4, GL_MAP2_INDEX, GL_MAP2_COLOR_4, GL_MAP2_NORMAL, GL_MAP2_TEXTURE_COORD_1, GL_MAP2_TEXTURE_COORD_2, GL_MAP2_TEXTURE_COORD_3, and GL_MAP2_TEXTURE_COORD_4 are accepted.
u1
u2: Specify a linear mapping of u, as presented to glEvalCoord2, to u^, one of the two variables that are evaluated by the equations specified by this command. Initially, u1 is 0 and u2 is 1.
ustride: Specifies the number of floats or doubles between the beginning of control point R_ij and the beginning of control point R_(i+1,)â¢j,, where i and j are the u and v control point indices, respectively. This allows control points to be embedded in arbitrary data structures. The only constraint is that the values for a particular control point must occupy contiguous memory locations. The initial value of ustride is 0.
uorder: Specifies the dimension of the control point array in the u axis. Must be positive. The initial value is 1.
v1
v2: Specify a linear mapping of v, as presented to glEvalCoord2, to v^, one of the two variables that are evaluated by the equations specified by this command. Initially, v1 is 0 and v2 is 1.
vstride: Specifies the number of floats or doubles between the beginning of control point R_ij and the beginning of control point R_iâ¡(j+1,),, where i and j are the u and v control point indices, respectively. This allows control points to be embedded in arbitrary data structures. The only constraint is that the values for a particular control point must occupy contiguous memory locations. The initial value of vstride is 0.
vorder: Specifies the dimension of the control point array in the v axis. Must be positive. The initial value is 1.
points: Specifies a pointer to the array of control points.

Evaluators provide a way to use polynomial or rational polynomial mapping to produce vertices, normals, texture coordinates, and colors. The values produced by an evaluator are sent on to further stages of GL processing just as if they had been presented using glVertex, glNormal, glTexCoord, and glColor commands, except that the generated values do not update the current normal, texture coordinates, or color.

All polynomial or rational polynomial splines of any degree (up to the maximum degree supported by the GL implementation) can be described using evaluators. These include almost all surfaces used in computer graphics, including B-spline surfaces, NURBS surfaces, Bezier surfaces, and so on.

Evaluators define surfaces based on bivariate Bernstein polynomials. Define pâ¡(u^,v^) as

pâ¡(u^,v^)=Î£i=0nÎ£j=0mB_i,^nâ¡(u^,)â¢B_j,^mâ¡(v^,)â¢R_ij

where R_ij is a control point, B_i,^nâ¡(u^,) is the ith Bernstein polynomial of degree n (uorder = n+1)

B_i,^nâ¡(u^,)=((n), (i),,)â¢u^,^iâ¢(1-u^,)^n-i,,

and B_j,^mâ¡(v^,) is the jth Bernstein polynomial of degree m (vorder = m+1)

B_j,^mâ¡(v^,)=((m), (j),,)â¢v^,^jâ¢(1-v^,)^m-j,,

Recall that 0^0==1 and ((n), (0),,)==1

glMap2 is used to define the basis and to specify what kind of values are produced. Once defined, a map can be enabled and disabled by calling glEnable and glDisable with the map name, one of the nine predefined values for target, described below. When glEvalCoord2 presents values u and v, the bivariate Bernstein polynomials are evaluated using u^ and v^, where

u^=u-u1,/u2-u1,

v^=v-v1,/v2-v1,

GL_MAP2_VERTEX_3: Each control point is three floating-point values representing x, y, and z. Internal glVertex3 commands are generated when the map is evaluated.
GL_MAP2_VERTEX_4: Each control point is four floating-point values representing x, y, z, and w. Internal glVertex4 commands are generated when the map is evaluated.
GL_MAP2_INDEX: Each control point is a single floating-point value representing a color index. Internal glIndex commands are generated when the map is evaluated but the current index is not updated with the value of these glIndex commands.
GL_MAP2_COLOR_4: Each control point is four floating-point values representing red, green, blue, and alpha. Internal glColor4 commands are generated when the map is evaluated but the current color is not updated with the value of these glColor4 commands.
GL_MAP2_NORMAL: Each control point is three floating-point values representing the x, y, and z components of a normal vector. Internal glNormal commands are generated when the map is evaluated but the current normal is not updated with the value of these glNormal commands.
GL_MAP2_TEXTURE_COORD_1: Each control point is a single floating-point value representing the s texture coordinate. Internal glTexCoord1 commands are generated when the map is evaluated but the current texture coordinates are not updated with the value of these glTexCoord commands.
GL_MAP2_TEXTURE_COORD_2: Each control point is two floating-point values representing the s and t texture coordinates. Internal glTexCoord2 commands are generated when the map is evaluated but the current texture coordinates are not updated with the value of these glTexCoord commands.
GL_MAP2_TEXTURE_COORD_3: Each control point is three floating-point values representing the s, t, and r texture coordinates. Internal glTexCoord3 commands are generated when the map is evaluated but the current texture coordinates are not updated with the value of these glTexCoord commands.
GL_MAP2_TEXTURE_COORD_4: Each control point is four floating-point values representing the s, t, r, and q texture coordinates. Internal glTexCoord4 commands are generated when the map is evaluated but the current texture coordinates are not updated with the value of these glTexCoord commands.

ustride, uorder, vstride, vorder, and points define the array addressing for accessing the control points. points is the location of the first control point, which occupies one, two, three, or four contiguous memory locations, depending on which map is being defined. There are uorderÃvorder control points in the array. ustride specifies how many float or double locations are skipped to advance the internal memory pointer from control point R_iâ¢j, to control point R_(i+1,)â¢j,. vstride specifies how many float or double locations are skipped to advance the internal memory pointer from control point R_iâ¢j, to control point R_iâ¡(j+1,),.

GL_INVALID_ENUM is generated if target is not an accepted value.

GL_INVALID_VALUE is generated if u1 is equal to u2, or if v1 is equal to v2.

GL_INVALID_VALUE is generated if either ustride or vstride is less than the number of values in a control point.

GL_INVALID_VALUE is generated if either uorder or vorder is less than 1 or greater than the return value of GL_MAX_EVAL_ORDER.

GL_INVALID_OPERATION is generated if glMap2 is executed between the execution of glBegin and the corresponding execution of glEnd.

GL_INVALID_OPERATION is generated if glMap2 is called and the value of GL_ACTIVE_TEXTURE is not GL_TEXTURE0.

Function: void-* glMapBuffer target access

Function: GLboolean glUnmapBuffer target

Map a buffer object’s data store.

target: Specifies the target buffer object being mapped. The symbolic constant must be GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.
access: Specifies the access policy, indicating whether it will be possible to read from, write to, or both read from and write to the buffer object’s mapped data store. The symbolic constant must be GL_READ_ONLY, GL_WRITE_ONLY, or GL_READ_WRITE.

glMapBuffer maps to the client’s address space the entire data store of the buffer object currently bound to target. The data can then be directly read and/or written relative to the returned pointer, depending on the specified access policy. If the GL is unable to map the buffer object’s data store, glMapBuffer generates an error and returns NULL. This may occur for system-specific reasons, such as low virtual memory availability.

If a mapped data store is accessed in a way inconsistent with the specified access policy, no error is generated, but performance may be negatively impacted and system errors, including program termination, may result. Unlike the usage parameter of glBufferData, access is not a hint, and does in fact constrain the usage of the mapped data store on some GL implementations. In order to achieve the highest performance available, a buffer object’s data store should be used in ways consistent with both its specified usage and access parameters.

A mapped data store must be unmapped with glUnmapBuffer before its buffer object is used. Otherwise an error will be generated by any GL command that attempts to dereference the buffer object’s data store. When a data store is unmapped, the pointer to its data store becomes invalid. glUnmapBuffer returns GL_TRUE unless the data store contents have become corrupt during the time the data store was mapped. This can occur for system-specific reasons that affect the availability of graphics memory, such as screen mode changes. In such situations, GL_FALSE is returned and the data store contents are undefined. An application must detect this rare condition and reinitialize the data store.

A buffer object’s mapped data store is automatically unmapped when the buffer object is deleted or its data store is recreated with glBufferData.

GL_INVALID_ENUM is generated if target is not GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.

GL_INVALID_ENUM is generated if access is not GL_READ_ONLY, GL_WRITE_ONLY, or GL_READ_WRITE.

GL_OUT_OF_MEMORY is generated when glMapBuffer is executed if the GL is unable to map the buffer object’s data store. This may occur for a variety of system-specific reasons, such as the absence of sufficient remaining virtual memory.

GL_INVALID_OPERATION is generated if the reserved buffer object name 0 is bound to target.

GL_INVALID_OPERATION is generated if glMapBuffer is executed for a buffer object whose data store is already mapped.

GL_INVALID_OPERATION is generated if glUnmapBuffer is executed for a buffer object whose data store is not currently mapped.

GL_INVALID_OPERATION is generated if glMapBuffer or glUnmapBuffer is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glMapGrid1d un u1 u2

Function: void glMapGrid1f un u1 u2

Function: void glMapGrid2d un u1 u2 vn v1 v2

Function: void glMapGrid2f un u1 u2 vn v1 v2

Define a one- or two-dimensional mesh.

un: Specifies the number of partitions in the grid range interval [u1, u2]. Must be positive.
u1
u2: Specify the mappings for integer grid domain values i=0 and i=un.
vn: Specifies the number of partitions in the grid range interval [v1, v2] (glMapGrid2 only).
v1
v2: Specify the mappings for integer grid domain values j=0 and j=vn (glMapGrid2 only).

glMapGrid and glEvalMesh are used together to efficiently generate and evaluate a series of evenly-spaced map domain values. glEvalMesh steps through the integer domain of a one- or two-dimensional grid, whose range is the domain of the evaluation maps specified by glMap1 and glMap2.

glMapGrid1 and glMapGrid2 specify the linear grid mappings between the i (or i and j) integer grid coordinates, to the u (or u and v) floating-point evaluation map coordinates. See glMap1 and glMap2 for details of how u and v coordinates are evaluated.

glMapGrid1 specifies a single linear mapping such that integer grid coordinate 0 maps exactly to u1, and integer grid coordinate un maps exactly to u2. All other integer grid coordinates i are mapped so that

u=iâ¡(u2-u1,)/un+u1

glMapGrid2 specifies two such linear mappings. One maps integer grid coordinate i=0 exactly to u1, and integer grid coordinate i=un exactly to u2. The other maps integer grid coordinate j=0 exactly to v1, and integer grid coordinate j=vn exactly to v2. Other integer grid coordinates i and j are mapped such that

u=iâ¡(u2-u1,)/un+u1

v=jâ¡(v2-v1,)/vn+v1

The mappings specified by glMapGrid are used identically by glEvalMesh and glEvalPoint.

GL_INVALID_VALUE is generated if either un or vn is not positive.

GL_INVALID_OPERATION is generated if glMapGrid is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glMaterialf face pname param

Function: void glMateriali face pname param

Function: void glMaterialfv face pname params

Function: void glMaterialiv face pname params

Specify material parameters for the lighting model.

face: Specifies which face or faces are being updated. Must be one of GL_FRONT, GL_BACK, or GL_FRONT_AND_BACK.
pname: Specifies the single-valued material parameter of the face or faces that is being updated. Must be GL_SHININESS.
param: Specifies the value that parameter GL_SHININESS will be set to.

glMaterial assigns values to material parameters. There are two matched sets of material parameters. One, the front-facing set, is used to shade points, lines, bitmaps, and all polygons (when two-sided lighting is disabled), or just front-facing polygons (when two-sided lighting is enabled). The other set, back-facing, is used to shade back-facing polygons only when two-sided lighting is enabled. Refer to the glLightModel reference page for details concerning one- and two-sided lighting calculations.

glMaterial takes three arguments. The first, face, specifies whether the GL_FRONT materials, the GL_BACK materials, or both GL_FRONT_AND_BACK materials will be modified. The second, pname, specifies which of several parameters in one or both sets will be modified. The third, params, specifies what value or values will be assigned to the specified parameter.

Material parameters are used in the lighting equation that is optionally applied to each vertex. The equation is discussed in the glLightModel reference page. The parameters that can be specified using glMaterial, and their interpretations by the lighting equation, are as follows:

GL_AMBIENT: params contains four integer or floating-point values that specify the ambient RGBA reflectance of the material. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial ambient reflectance for both front- and back-facing materials is (0.2, 0.2, 0.2, 1.0).
GL_DIFFUSE: params contains four integer or floating-point values that specify the diffuse RGBA reflectance of the material. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial diffuse reflectance for both front- and back-facing materials is (0.8, 0.8, 0.8, 1.0).
GL_SPECULAR: params contains four integer or floating-point values that specify the specular RGBA reflectance of the material. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial specular reflectance for both front- and back-facing materials is (0, 0, 0, 1).
GL_EMISSION: params contains four integer or floating-point values that specify the RGBA emitted light intensity of the material. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial emission intensity for both front- and back-facing materials is (0, 0, 0, 1).
GL_SHININESS: params is a single integer or floating-point value that specifies the RGBA specular exponent of the material. Integer and floating-point values are mapped directly. Only values in the range [0,128] are accepted. The initial specular exponent for both front- and back-facing materials is 0.
GL_AMBIENT_AND_DIFFUSE: Equivalent to calling glMaterial twice with the same parameter values, once with GL_AMBIENT and once with GL_DIFFUSE.
GL_COLOR_INDEXES: params contains three integer or floating-point values specifying the color indices for ambient, diffuse, and specular lighting. These three values, and GL_SHININESS, are the only material values used by the color index mode lighting equation. Refer to the glLightModel reference page for a discussion of color index lighting.

GL_INVALID_ENUM is generated if either face or pname is not an accepted value.

GL_INVALID_VALUE is generated if a specular exponent outside the range [0,128] is specified.

Function: void glMatrixMode mode

Specify which matrix is the current matrix.

mode: Specifies which matrix stack is the target for subsequent matrix operations. Three values are accepted: GL_MODELVIEW, GL_PROJECTION, and GL_TEXTURE. The initial value is GL_MODELVIEW. Additionally, if the ARB_imaging extension is supported, GL_COLOR is also accepted.

glMatrixMode sets the current matrix mode. mode can assume one of four values:

GL_MODELVIEW: Applies subsequent matrix operations to the modelview matrix stack.
GL_PROJECTION: Applies subsequent matrix operations to the projection matrix stack.
GL_TEXTURE: Applies subsequent matrix operations to the texture matrix stack.
GL_COLOR: Applies subsequent matrix operations to the color matrix stack.

To find out which matrix stack is currently the target of all matrix operations, call glGet with argument GL_MATRIX_MODE. The initial value is GL_MODELVIEW.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_OPERATION is generated if glMatrixMode is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glMinmax target internalformat sink

Define minmax table.

target: The minmax table whose parameters are to be set. Must be GL_MINMAX.
internalformat: The format of entries in the minmax table. Must be one of GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
sink: If GL_TRUE, pixels will be consumed by the minmax process and no drawing or texture loading will take place. If GL_FALSE, pixels will proceed to the final conversion process after minmax.

When GL_MINMAX is enabled, the RGBA components of incoming pixels are compared to the minimum and maximum values for each component, which are stored in the two-element minmax table. (The first element stores the minima, and the second element stores the maxima.) If a pixel component is greater than the corresponding component in the maximum element, then the maximum element is updated with the pixel component value. If a pixel component is less than the corresponding component in the minimum element, then the minimum element is updated with the pixel component value. (In both cases, if the internal format of the minmax table includes luminance, then the R color component of incoming pixels is used for comparison.) The contents of the minmax table may be retrieved at a later time by calling glGetMinmax. The minmax operation is enabled or disabled by calling glEnable or glDisable, respectively, with an argument of GL_MINMAX.

glMinmax redefines the current minmax table to have entries of the format specified by internalformat. The maximum element is initialized with the smallest possible component values, and the minimum element is initialized with the largest possible component values. The values in the previous minmax table, if any, are lost. If sink is GL_TRUE, then pixels are discarded after minmax; no further processing of the pixels takes place, and no drawing, texture loading, or pixel readback will result.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if internalformat is not one of the allowable values.

GL_INVALID_OPERATION is generated if glMinmax is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glMultiDrawArrays mode first count primcount

Render multiple sets of primitives from array data.

mode: Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES, GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
first: Points to an array of starting indices in the enabled arrays.
count: Points to an array of the number of indices to be rendered.
primcount: Specifies the size of the first and count

glMultiDrawArrays specifies multiple sets of geometric primitives with very few subroutine calls. Instead of calling a GL procedure to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify separate arrays of vertices, normals, and colors and use them to construct a sequence of primitives with a single call to glMultiDrawArrays.

glMultiDrawArrays behaves identically to glDrawArrays except that primcount separate ranges of elements are specified instead.

When glMultiDrawArrays is called, it uses count sequential elements from each enabled array to construct a sequence of geometric primitives, beginning with element first. mode specifies what kind of primitives are constructed, and how the array elements construct those primitives. If GL_VERTEX_ARRAY is not enabled, no geometric primitives are generated.

Vertex attributes that are modified by glMultiDrawArrays have an unspecified value after glMultiDrawArrays returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current color is undefined after glMultiDrawArrays executes. Attributes that aren’t modified remain well defined.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_VALUE is generated if primcount is negative.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glMultiDrawArrays is executed between the execution of glBegin and the corresponding glEnd.

Function: void glMultiDrawElements mode count type indices primcount

Render multiple sets of primitives by specifying indices of array data elements.

mode: Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES, GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.
count: Points to an array of the elements counts.
type: Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.
indices: Specifies a pointer to the location where the indices are stored.
primcount: Specifies the size of the count array.

glMultiDrawElements specifies multiple sets of geometric primitives with very few subroutine calls. Instead of calling a GL function to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify separate arrays of vertices, normals, and so on, and use them to construct a sequence of primitives with a single call to glMultiDrawElements.

glMultiDrawElements is identical in operation to glDrawElements except that primcount separate lists of elements are specified.

Vertex attributes that are modified by glMultiDrawElements have an unspecified value after glMultiDrawElements returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current color is undefined after glMultiDrawElements executes. Attributes that aren’t modified maintain their previous values.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_VALUE is generated if primcount is negative.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array or the element array and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glMultiDrawElements is executed between the execution of glBegin and the corresponding glEnd.

Function: void glMultiTexCoord1s target s

Function: void glMultiTexCoord1i target s

Function: void glMultiTexCoord1f target s

Function: void glMultiTexCoord1d target s

Function: void glMultiTexCoord2s target s t

Function: void glMultiTexCoord2i target s t

Function: void glMultiTexCoord2f target s t

Function: void glMultiTexCoord2d target s t

Function: void glMultiTexCoord3s target s t r

Function: void glMultiTexCoord3i target s t r

Function: void glMultiTexCoord3f target s t r

Function: void glMultiTexCoord3d target s t r

Function: void glMultiTexCoord4s target s t r q

Function: void glMultiTexCoord4i target s t r q

Function: void glMultiTexCoord4f target s t r q

Function: void glMultiTexCoord4d target s t r q

Function: void glMultiTexCoord1sv target v

Function: void glMultiTexCoord1iv target v

Function: void glMultiTexCoord1fv target v

Function: void glMultiTexCoord1dv target v

Function: void glMultiTexCoord2sv target v

Function: void glMultiTexCoord2iv target v

Function: void glMultiTexCoord2fv target v

Function: void glMultiTexCoord2dv target v

Function: void glMultiTexCoord3sv target v

Function: void glMultiTexCoord3iv target v

Function: void glMultiTexCoord3fv target v

Function: void glMultiTexCoord3dv target v

Function: void glMultiTexCoord4sv target v

Function: void glMultiTexCoord4iv target v

Function: void glMultiTexCoord4fv target v

Function: void glMultiTexCoord4dv target v

Set the current texture coordinates.

target: Specifies the texture unit whose coordinates should be modified. The number of texture units is implementation dependent, but must be at least two. Symbolic constant must be one of GL_TEXTUREi, where i ranges from 0 to GL_MAX_TEXTURE_COORDS - 1, which is an implementation-dependent value.
s
t
r
q: Specify s, t, r, and q texture coordinates for target texture unit. Not all parameters are present in all forms of the command.

glMultiTexCoord specifies texture coordinates in one, two, three, or four dimensions. glMultiTexCoord1 sets the current texture coordinates to (s,001); a call to glMultiTexCoord2 sets them to (s,t01). Similarly, glMultiTexCoord3 specifies the texture coordinates as (s,tr1), and glMultiTexCoord4 defines all four components explicitly as (s,trq).

The current texture coordinates are part of the data that is associated with each vertex and with the current raster position. Initially, the values for (s,trq) are (0,001).

Function: void glMultMatrixd m

Function: void glMultMatrixf m

Multiply the current matrix with the specified matrix.

m: Points to 16 consecutive values that are used as the elements of a 4Ã4 column-major matrix.

glMultMatrix multiplies the current matrix with the one specified using m, and replaces the current matrix with the product.

The current matrix is determined by the current matrix mode (see glMatrixMode). It is either the projection matrix, modelview matrix, or the texture matrix.

GL_INVALID_OPERATION is generated if glMultMatrix is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glMultTransposeMatrixd m

Function: void glMultTransposeMatrixf m

Multiply the current matrix with the specified row-major ordered matrix.

m: Points to 16 consecutive values that are used as the elements of a 4Ã4 row-major matrix.

glMultTransposeMatrix multiplies the current matrix with the one specified using m, and replaces the current matrix with the product.

The current matrix is determined by the current matrix mode (see glMatrixMode). It is either the projection matrix, modelview matrix, or the texture matrix.

GL_INVALID_OPERATION is generated if glMultTransposeMatrix is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glNewList list mode

Function: void glEndList

Create or replace a display list.

list: Specifies the display-list name.
mode: Specifies the compilation mode, which can be GL_COMPILE or GL_COMPILE_AND_EXECUTE.

Display lists are groups of GL commands that have been stored for subsequent execution. Display lists are created with glNewList. All subsequent commands are placed in the display list, in the order issued, until glEndList is called.

glNewList has two arguments. The first argument, list, is a positive integer that becomes the unique name for the display list. Names can be created and reserved with glGenLists and tested for uniqueness with glIsList. The second argument, mode, is a symbolic constant that can assume one of two values:

GL_COMPILE: Commands are merely compiled.
GL_COMPILE_AND_EXECUTE: Commands are executed as they are compiled into the display list.

Certain commands are not compiled into the display list but are executed immediately, regardless of the display-list mode. These commands are glAreTexturesResident, glColorPointer, glDeleteLists, glDeleteTextures, glDisableClientState, glEdgeFlagPointer, glEnableClientState, glFeedbackBuffer, glFinish, glFlush, glGenLists, glGenTextures, glIndexPointer, glInterleavedArrays, glIsEnabled, glIsList, glIsTexture, glNormalPointer, glPopClientAttrib, glPixelStore, glPushClientAttrib, glReadPixels, glRenderMode, glSelectBuffer, glTexCoordPointer, glVertexPointer, and all of the glGet commands.

Similarly, glTexImage1D, glTexImage2D, and glTexImage3D are executed immediately and not compiled into the display list when their first argument is GL_PROXY_TEXTURE_1D, GL_PROXY_TEXTURE_1D, or GL_PROXY_TEXTURE_3D, respectively.

When the ARB_imaging extension is supported, glHistogram executes immediately when its argument is GL_PROXY_HISTOGRAM. Similarly, glColorTable executes immediately when its first argument is GL_PROXY_COLOR_TABLE, GL_PROXY_POST_CONVOLUTION_COLOR_TABLE, or GL_PROXY_POST_COLOR_MATRIX_COLOR_TABLE.

For OpenGL versions 1.3 and greater, or when the ARB_multitexture extension is supported, glClientActiveTexture is not compiled into display lists, but executed immediately.

When glEndList is encountered, the display-list definition is completed by associating the list with the unique name list (specified in the glNewList command). If a display list with name list already exists, it is replaced only when glEndList is called.

GL_INVALID_VALUE is generated if list is 0.

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_OPERATION is generated if glEndList is called without a preceding glNewList, or if glNewList is called while a display list is being defined.

GL_INVALID_OPERATION is generated if glNewList or glEndList is executed between the execution of glBegin and the corresponding execution of glEnd.

GL_OUT_OF_MEMORY is generated if there is insufficient memory to compile the display list. If the GL version is 1.1 or greater, no change is made to the previous contents of the display list, if any, and no other change is made to the GL state. (It is as if no attempt had been made to create the new display list.)

Function: void glNormalPointer type stride pointer

Define an array of normals.

type: Specifies the data type of each coordinate in the array. Symbolic constants GL_BYTE, GL_SHORT, GL_INT, GL_FLOAT, and GL_DOUBLE are accepted. The initial value is GL_FLOAT.
stride: Specifies the byte offset between consecutive normals. If stride is 0, the normals are understood to be tightly packed in the array. The initial value is 0.
pointer: Specifies a pointer to the first coordinate of the first normal in the array. The initial value is 0.

glNormalPointer specifies the location and data format of an array of normals to use when rendering. type specifies the data type of each normal coordinate, and stride specifies the byte stride from one normal to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on some implementations; see glInterleavedArrays.)

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer) while a normal array is specified, pointer is treated as a byte offset into the buffer object’s data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as normal vertex array client-side state (GL_NORMAL_ARRAY_BUFFER_BINDING).

When a normal array is specified, type, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable the normal array, call glEnableClientState and glDisableClientState with the argument GL_NORMAL_ARRAY. If enabled, the normal array is used when glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, glDrawRangeElements, or glArrayElement is called.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if stride is negative.

Function: void glNormal3b nx ny nz

Function: void glNormal3d nx ny nz

Function: void glNormal3f nx ny nz

Function: void glNormal3i nx ny nz

Function: void glNormal3s nx ny nz

Function: void glNormal3bv v

Function: void glNormal3dv v

Function: void glNormal3fv v

Function: void glNormal3iv v

Function: void glNormal3sv v

Set the current normal vector.

nx
ny
nz: Specify the x, y, and z coordinates of the new current normal. The initial value of the current normal is the unit vector, (0, 0, 1).

The current normal is set to the given coordinates whenever glNormal is issued. Byte, short, or integer arguments are converted to floating-point format with a linear mapping that maps the most positive representable integer value to 1.0 and the most negative representable integer value to -1.0.

Normals specified with glNormal need not have unit length. If GL_NORMALIZE is enabled, then normals of any length specified with glNormal are normalized after transformation. If GL_RESCALE_NORMAL is enabled, normals are scaled by a scaling factor derived from the modelview matrix. GL_RESCALE_NORMAL requires that the originally specified normals were of unit length, and that the modelview matrix contain only uniform scales for proper results. To enable and disable normalization, call glEnable and glDisable with either GL_NORMALIZE or GL_RESCALE_NORMAL. Normalization is initially disabled.

Function: void glOrtho left right bottom top nearVal farVal

Multiply the current matrix with an orthographic matrix.

left
right: Specify the coordinates for the left and right vertical clipping planes.
bottom
top: Specify the coordinates for the bottom and top horizontal clipping planes.
nearVal
farVal: Specify the distances to the nearer and farther depth clipping planes. These values are negative if the plane is to be behind the viewer.

glOrtho describes a transformation that produces a parallel projection. The current matrix (see glMatrixMode) is multiplied by this matrix and the result replaces the current matrix, as if glMultMatrix were called with the following matrix as its argument:

((2/right-left,, 0 0 t_x,), (0 2/top-bottom,, 0 t_y,), (0 0 -2/farVal-nearVal,, t_z,), (0 0 0 1),)

where t_x=-right+left,/right-left,,t_y=-top+bottom,/top-bottom,,t_z=-farVal+nearVal,/farVal-nearVal,,

Typically, the matrix mode is GL_PROJECTION, and (left,bottom-nearVal) and (right,top-nearVal) specify the points on the near clipping plane that are mapped to the lower left and upper right corners of the window, respectively, assuming that the eye is located at (0, 0, 0). -farVal specifies the location of the far clipping plane. Both nearVal and farVal can be either positive or negative.

Use glPushMatrix and glPopMatrix to save and restore the current matrix stack.

GL_INVALID_VALUE is generated if left = right, or bottom = top, or near = far.

GL_INVALID_OPERATION is generated if glOrtho is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPassThrough token

Place a marker in the feedback buffer.

token: Specifies a marker value to be placed in the feedback buffer following a GL_PASS_THROUGH_TOKEN.

Feedback is a GL render mode. The mode is selected by calling glRenderMode with GL_FEEDBACK. When the GL is in feedback mode, no pixels are produced by rasterization. Instead, information about primitives that would have been rasterized is fed back to the application using the GL. See the glFeedbackBuffer reference page for a description of the feedback buffer and the values in it.

glPassThrough inserts a user-defined marker in the feedback buffer when it is executed in feedback mode. token is returned as if it were a primitive; it is indicated with its own unique identifying value: GL_PASS_THROUGH_TOKEN. The order of glPassThrough commands with respect to the specification of graphics primitives is maintained.

GL_INVALID_OPERATION is generated if glPassThrough is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPixelMapfv map mapsize values

Function: void glPixelMapuiv map mapsize values

Function: void glPixelMapusv map mapsize values

Set up pixel transfer maps.

map: Specifies a symbolic map name. Must be one of the following: GL_PIXEL_MAP_I_TO_I, GL_PIXEL_MAP_S_TO_S, GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, GL_PIXEL_MAP_I_TO_A, GL_PIXEL_MAP_R_TO_R, GL_PIXEL_MAP_G_TO_G, GL_PIXEL_MAP_B_TO_B, or GL_PIXEL_MAP_A_TO_A.
mapsize: Specifies the size of the map being defined.
values: Specifies an array of mapsize values.

glPixelMap sets up translation tables, or maps, used by glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, glDrawPixels, glReadPixels, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, and glTexSubImage3D. Additionally, if the ARB_imaging subset is supported, the routines glColorTable, glColorSubTable, glConvolutionFilter1D, glConvolutionFilter2D, glHistogram, glMinmax, and glSeparableFilter2D. Use of these maps is described completely in the glPixelTransfer reference page, and partly in the reference pages for the pixel and texture image commands. Only the specification of the maps is described in this reference page.

map is a symbolic map name, indicating one of ten maps to set. mapsize specifies the number of entries in the map, and values is a pointer to an array of mapsize map values.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a pixel transfer map is specified, values is treated as a byte offset into the buffer object’s data store.

The ten maps are as follows:

GL_PIXEL_MAP_I_TO_I: Maps color indices to color indices.
GL_PIXEL_MAP_S_TO_S: Maps stencil indices to stencil indices.
GL_PIXEL_MAP_I_TO_R: Maps color indices to red components.
GL_PIXEL_MAP_I_TO_G: Maps color indices to green components.
GL_PIXEL_MAP_I_TO_B: Maps color indices to blue components.
GL_PIXEL_MAP_I_TO_A: Maps color indices to alpha components.
GL_PIXEL_MAP_R_TO_R: Maps red components to red components.
GL_PIXEL_MAP_G_TO_G: Maps green components to green components.
GL_PIXEL_MAP_B_TO_B: Maps blue components to blue components.
GL_PIXEL_MAP_A_TO_A: Maps alpha components to alpha components.

The entries in a map can be specified as single-precision floating-point numbers, unsigned short integers, or unsigned int integers. Maps that store color component values (all but GL_PIXEL_MAP_I_TO_I and GL_PIXEL_MAP_S_TO_S) retain their values in floating-point format, with unspecified mantissa and exponent sizes. Floating-point values specified by glPixelMapfv are converted directly to the internal floating-point format of these maps, then clamped to the range [0,1]. Unsigned integer values specified by glPixelMapusv and glPixelMapuiv are converted linearly such that the largest representable integer maps to 1.0, and 0 maps to 0.0.

Maps that store indices, GL_PIXEL_MAP_I_TO_I and GL_PIXEL_MAP_S_TO_S, retain their values in fixed-point format, with an unspecified number of bits to the right of the binary point. Floating-point values specified by glPixelMapfv are converted directly to the internal fixed-point format of these maps. Unsigned integer values specified by glPixelMapusv and glPixelMapuiv specify integer values, with all 0’s to the right of the binary point.

The following table shows the initial sizes and values for each of the maps. Maps that are indexed by either color or stencil indices must have mapsize = 2^n for some n or the results are undefined. The maximum allowable size for each map depends on the implementation and can be determined by calling glGet with argument GL_MAX_PIXEL_MAP_TABLE. The single maximum applies to all maps; it is at least 32.

map: Lookup Index, Lookup Value, Initial Size, Initial Value
GL_PIXEL_MAP_I_TO_I: color index , color index , 1 , 0
GL_PIXEL_MAP_S_TO_S: stencil index , stencil index , 1 , 0
GL_PIXEL_MAP_I_TO_R: color index , R , 1 , 0
GL_PIXEL_MAP_I_TO_G: color index , G , 1 , 0
GL_PIXEL_MAP_I_TO_B: color index , B , 1 , 0
GL_PIXEL_MAP_I_TO_A: color index , A , 1 , 0
GL_PIXEL_MAP_R_TO_R: R , R , 1 , 0
GL_PIXEL_MAP_G_TO_G: G , G , 1 , 0
GL_PIXEL_MAP_B_TO_B: B , B , 1 , 0
GL_PIXEL_MAP_A_TO_A: A , A , 1 , 0

GL_INVALID_ENUM is generated if map is not an accepted value.

GL_INVALID_VALUE is generated if mapsize is less than one or larger than GL_MAX_PIXEL_MAP_TABLE.

GL_INVALID_VALUE is generated if map is GL_PIXEL_MAP_I_TO_I, GL_PIXEL_MAP_S_TO_S, GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, or GL_PIXEL_MAP_I_TO_A, and mapsize is not a power of two.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated by glPixelMapfv if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and values is not evenly divisible into the number of bytes needed to store in memory a GLfloat datum.

GL_INVALID_OPERATION is generated by glPixelMapuiv if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and values is not evenly divisible into the number of bytes needed to store in memory a GLuint datum.

GL_INVALID_OPERATION is generated by glPixelMapusv if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and values is not evenly divisible into the number of bytes needed to store in memory a GLushort datum.

GL_INVALID_OPERATION is generated if glPixelMap is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPixelStoref pname param

Function: void glPixelStorei pname param

Set pixel storage modes.

pname: Specifies the symbolic name of the parameter to be set. Six values affect the packing of pixel data into memory: GL_PACK_SWAP_BYTES, GL_PACK_LSB_FIRST, GL_PACK_ROW_LENGTH, GL_PACK_IMAGE_HEIGHT, GL_PACK_SKIP_PIXELS, GL_PACK_SKIP_ROWS, GL_PACK_SKIP_IMAGES, and GL_PACK_ALIGNMENT. Six more affect the unpacking of pixel data from memory: GL_UNPACK_SWAP_BYTES, GL_UNPACK_LSB_FIRST, GL_UNPACK_ROW_LENGTH, GL_UNPACK_IMAGE_HEIGHT, GL_UNPACK_SKIP_PIXELS, GL_UNPACK_SKIP_ROWS, GL_UNPACK_SKIP_IMAGES, and GL_UNPACK_ALIGNMENT.
param: Specifies the value that pname is set to.

glPixelStore sets pixel storage modes that affect the operation of subsequent glDrawPixels and glReadPixels as well as the unpacking of polygon stipple patterns (see glPolygonStipple), bitmaps (see glBitmap), texture patterns (see glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D). Additionally, if the ARB_imaging extension is supported, pixel storage modes affect convolution filters (see glConvolutionFilter1D, glConvolutionFilter2D, and glSeparableFilter2D, color table (see glColorTable, and glColorSubTable, and unpacking histogram (See glHistogram), and minmax (See glMinmax) data.

pname is a symbolic constant indicating the parameter to be set, and param is the new value. Six of the twelve storage parameters affect how pixel data is returned to client memory. They are as follows:

GL_PACK_SWAP_BYTES

If true, byte ordering for multibyte color components, depth components, color indices, or stencil indices is reversed. That is, if a four-byte component consists of bytes b_0, b_1, b_2, b_3, it is stored in memory as b_3, b_2, b_1, b_0 if GL_PACK_SWAP_BYTES is true. GL_PACK_SWAP_BYTES has no effect on the memory order of components within a pixel, only on the order of bytes within components or indices. For example, the three components of a GL_RGB format pixel are always stored with red first, green second, and blue third, regardless of the value of GL_PACK_SWAP_BYTES.

GL_PACK_LSB_FIRST

If true, bits are ordered within a byte from least significant to most significant; otherwise, the first bit in each byte is the most significant one. This parameter is significant for bitmap data only.

GL_PACK_ROW_LENGTH

If greater than 0, GL_PACK_ROW_LENGTH defines the number of pixels in a row. If the first pixel of a row is placed at location p in memory, then the location of the first pixel of the next row is obtained by skipping

k={(nâ¢l), (a/s,â¢âsâ¢nâ¢l,/a,â)â¢(s>=a), (s<a),

components or indices, where n is the number of components or indices in a pixel, l is the number of pixels in a row (GL_PACK_ROW_LENGTH if it is greater than 0, the width argument to the pixel routine otherwise), a is the value of GL_PACK_ALIGNMENT, and s is the size, in bytes, of a single component (if a<s, then it is as if a=s). In the case of 1-bit values, the location of the next row is obtained by skipping

k=8â¢aâ¢ânâ¢l,/8â¢a,,â

components or indices.

The word component in this description refers to the nonindex values red, green, blue, alpha, and depth. Storage format GL_RGB, for example, has three components per pixel: first red, then green, and finally blue.

GL_PACK_IMAGE_HEIGHT

If greater than 0, GL_PACK_IMAGE_HEIGHT defines the number of pixels in an image three-dimensional texture volume, where “image” is defined by all pixels sharing the same third dimension index. If the first pixel of a row is placed at location p in memory, then the location of the first pixel of the next row is obtained by skipping

k={(nâ¢lâ¢h), (a/s,â¢âsâ¢nâ¢lâ¢h,/a,â)â¢(s>=a), (s<a),

components or indices, where n is the number of components or indices in a pixel, l is the number of pixels in a row (GL_PACK_ROW_LENGTH if it is greater than 0, the width argument to glTexImage3D otherwise), h is the number of rows in a pixel image (GL_PACK_IMAGE_HEIGHT if it is greater than 0, the height argument to the glTexImage3D routine otherwise), a is the value of GL_PACK_ALIGNMENT, and s is the size, in bytes, of a single component (if a<s, then it is as if a=s).

GL_PACK_SKIP_PIXELS, GL_PACK_SKIP_ROWS, and GL_PACK_SKIP_IMAGES

These values are provided as a convenience to the programmer; they provide no functionality that cannot be duplicated simply by incrementing the pointer passed to glReadPixels. Setting GL_PACK_SKIP_PIXELS to i is equivalent to incrementing the pointer by iâ¢n components or indices, where n is the number of components or indices in each pixel. Setting GL_PACK_SKIP_ROWS to j is equivalent to incrementing the pointer by jâ¢m components or indices, where m is the number of components or indices per row, as just computed in the GL_PACK_ROW_LENGTH section. Setting GL_PACK_SKIP_IMAGES to k is equivalent to incrementing the pointer by kâ¢p, where p is the number of components or indices per image, as computed in the GL_PACK_IMAGE_HEIGHT section.

GL_PACK_ALIGNMENT

Specifies the alignment requirements for the start of each pixel row in memory. The allowable values are 1 (byte-alignment), 2 (rows aligned to even-numbered bytes), 4 (word-alignment), and 8 (rows start on double-word boundaries).

The other six of the twelve storage parameters affect how pixel data is read from client memory. These values are significant for glDrawPixels, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D, glBitmap, and glPolygonStipple.

Additionally, if the ARB_imaging extension is supported, glColorTable, glColorSubTable, glConvolutionFilter1D, glConvolutionFilter2D, and glSeparableFilter2D. They are as follows:

GL_UNPACK_SWAP_BYTES

If true, byte ordering for multibyte color components, depth components, color indices, or stencil indices is reversed. That is, if a four-byte component consists of bytes b_0, b_1, b_2, b_3, it is taken from memory as b_3, b_2, b_1, b_0 if GL_UNPACK_SWAP_BYTES is true. GL_UNPACK_SWAP_BYTES has no effect on the memory order of components within a pixel, only on the order of bytes within components or indices. For example, the three components of a GL_RGB format pixel are always stored with red first, green second, and blue third, regardless of the value of GL_UNPACK_SWAP_BYTES.

GL_UNPACK_LSB_FIRST

If true, bits are ordered within a byte from least significant to most significant; otherwise, the first bit in each byte is the most significant one. This is relevant only for bitmap data.

GL_UNPACK_ROW_LENGTH

If greater than 0, GL_UNPACK_ROW_LENGTH defines the number of pixels in a row. If the first pixel of a row is placed at location p in memory, then the location of the first pixel of the next row is obtained by skipping

k={(nâ¢l), (a/s,â¢âsâ¢nâ¢l,/a,â)â¢(s>=a), (s<a),

components or indices, where n is the number of components or indices in a pixel, l is the number of pixels in a row (GL_UNPACK_ROW_LENGTH if it is greater than 0, the width argument to the pixel routine otherwise), a is the value of GL_UNPACK_ALIGNMENT, and s is the size, in bytes, of a single component (if a<s, then it is as if a=s). In the case of 1-bit values, the location of the next row is obtained by skipping

k=8â¢aâ¢ânâ¢l,/8â¢a,,â

components or indices.

GL_UNPACK_IMAGE_HEIGHT

If greater than 0, GL_UNPACK_IMAGE_HEIGHT defines the number of pixels in an image of a three-dimensional texture volume. Where “image” is defined by all pixel sharing the same third dimension index. If the first pixel of a row is placed at location p in memory, then the location of the first pixel of the next row is obtained by skipping

k={(nâ¢lâ¢h), (a/s,â¢âsâ¢nâ¢lâ¢h,/a,â)â¢(s>=a), (s<a),

components or indices, where n is the number of components or indices in a pixel, l is the number of pixels in a row (GL_UNPACK_ROW_LENGTH if it is greater than 0, the width argument to glTexImage3D otherwise), h is the number of rows in an image (GL_UNPACK_IMAGE_HEIGHT if it is greater than 0, the height argument to glTexImage3D otherwise), a is the value of GL_UNPACK_ALIGNMENT, and s is the size, in bytes, of a single component (if a<s, then it is as if a=s).

GL_UNPACK_SKIP_PIXELS and GL_UNPACK_SKIP_ROWS

These values are provided as a convenience to the programmer; they provide no functionality that cannot be duplicated by incrementing the pointer passed to glDrawPixels, glTexImage1D, glTexImage2D, glTexSubImage1D, glTexSubImage2D, glBitmap, or glPolygonStipple. Setting GL_UNPACK_SKIP_PIXELS to i is equivalent to incrementing the pointer by iâ¢n components or indices, where n is the number of components or indices in each pixel. Setting GL_UNPACK_SKIP_ROWS to j is equivalent to incrementing the pointer by jâ¢k components or indices, where k is the number of components or indices per row, as just computed in the GL_UNPACK_ROW_LENGTH section.

GL_UNPACK_ALIGNMENT

The following table gives the type, initial value, and range of valid values for each storage parameter that can be set with glPixelStore.

pname: Type, Initial Value, Valid Range
GL_PACK_SWAP_BYTES: boolean , false , true or false
GL_PACK_LSB_FIRST: boolean , false , true or false
GL_PACK_ROW_LENGTH: integer , 0 , [0,â)
GL_PACK_IMAGE_HEIGHT: integer , 0 , [0,â)
GL_PACK_SKIP_ROWS: integer , 0 , [0,â)
GL_PACK_SKIP_PIXELS: integer , 0 , [0,â)
GL_PACK_SKIP_IMAGES: integer , 0 , [0,â)
GL_PACK_ALIGNMENT: integer , 4 , 1, 2, 4, or 8
GL_UNPACK_SWAP_BYTES: boolean , false , true or false
GL_UNPACK_LSB_FIRST: boolean , false , true or false
GL_UNPACK_ROW_LENGTH: integer , 0 , [0,â)
GL_UNPACK_IMAGE_HEIGHT: integer , 0 , [0,â)
GL_UNPACK_SKIP_ROWS: integer , 0 , [0,â)
GL_UNPACK_SKIP_PIXELS: integer , 0 , [0,â)
GL_UNPACK_SKIP_IMAGES: integer , 0 , [0,â)
GL_UNPACK_ALIGNMENT: integer , 4 , 1, 2, 4, or 8

glPixelStoref can be used to set any pixel store parameter. If the parameter type is boolean, then if param is 0, the parameter is false; otherwise it is set to true. If pname is a integer type parameter, param is rounded to the nearest integer.

Likewise, glPixelStorei can also be used to set any of the pixel store parameters. Boolean parameters are set to false if param is 0 and true otherwise.

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_VALUE is generated if a negative row length, pixel skip, or row skip value is specified, or if alignment is specified as other than 1, 2, 4, or 8.

GL_INVALID_OPERATION is generated if glPixelStore is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPixelTransferf pname param

Function: void glPixelTransferi pname param

Set pixel transfer modes.

pname

Specifies the symbolic name of the pixel transfer parameter to be set. Must be one of the following: GL_MAP_COLOR, GL_MAP_STENCIL, GL_INDEX_SHIFT, GL_INDEX_OFFSET, GL_RED_SCALE, GL_RED_BIAS, GL_GREEN_SCALE, GL_GREEN_BIAS, GL_BLUE_SCALE, GL_BLUE_BIAS, GL_ALPHA_SCALE, GL_ALPHA_BIAS, GL_DEPTH_SCALE, or GL_DEPTH_BIAS.

Additionally, if the ARB_imaging extension is supported, the following symbolic names are accepted: GL_POST_COLOR_MATRIX_RED_SCALE, GL_POST_COLOR_MATRIX_GREEN_SCALE, GL_POST_COLOR_MATRIX_BLUE_SCALE, GL_POST_COLOR_MATRIX_ALPHA_SCALE, GL_POST_COLOR_MATRIX_RED_BIAS, GL_POST_COLOR_MATRIX_GREEN_BIAS, GL_POST_COLOR_MATRIX_BLUE_BIAS, GL_POST_COLOR_MATRIX_ALPHA_BIAS, GL_POST_CONVOLUTION_RED_SCALE, GL_POST_CONVOLUTION_GREEN_SCALE, GL_POST_CONVOLUTION_BLUE_SCALE, GL_POST_CONVOLUTION_ALPHA_SCALE, GL_POST_CONVOLUTION_RED_BIAS, GL_POST_CONVOLUTION_GREEN_BIAS, GL_POST_CONVOLUTION_BLUE_BIAS, and GL_POST_CONVOLUTION_ALPHA_BIAS.

param

Specifies the value that pname is set to.

glPixelTransfer sets pixel transfer modes that affect the operation of subsequent glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, glDrawPixels, glReadPixels, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, and glTexSubImage3D commands. Additionally, if the ARB_imaging subset is supported, the routines glColorTable, glColorSubTable, glConvolutionFilter1D, glConvolutionFilter2D, glHistogram, glMinmax, and glSeparableFilter2D are also affected. The algorithms that are specified by pixel transfer modes operate on pixels after they are read from the frame buffer (glCopyPixelsglCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, and glReadPixels), or unpacked from client memory (glDrawPixels, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, and glTexSubImage3D). Pixel transfer operations happen in the same order, and in the same manner, regardless of the command that resulted in the pixel operation. Pixel storage modes (see glPixelStore) control the unpacking of pixels being read from client memory and the packing of pixels being written back into client memory.

Pixel transfer operations handle four fundamental pixel types: color, color index, depth, and stencil. Color pixels consist of four floating-point values with unspecified mantissa and exponent sizes, scaled such that 0 represents zero intensity and 1 represents full intensity. Color indices comprise a single fixed-point value, with unspecified precision to the right of the binary point. Depth pixels comprise a single floating-point value, with unspecified mantissa and exponent sizes, scaled such that 0.0 represents the minimum depth buffer value, and 1.0 represents the maximum depth buffer value. Finally, stencil pixels comprise a single fixed-point value, with unspecified precision to the right of the binary point.

The pixel transfer operations performed on the four basic pixel types are as follows:

Color

Each of the four color components is multiplied by a scale factor, then added to a bias factor. That is, the red component is multiplied by GL_RED_SCALE, then added to GL_RED_BIAS; the green component is multiplied by GL_GREEN_SCALE, then added to GL_GREEN_BIAS; the blue component is multiplied by GL_BLUE_SCALE, then added to GL_BLUE_BIAS; and the alpha component is multiplied by GL_ALPHA_SCALE, then added to GL_ALPHA_BIAS. After all four color components are scaled and biased, each is clamped to the range [0,1]. All color, scale, and bias values are specified with glPixelTransfer.

If GL_MAP_COLOR is true, each color component is scaled by the size of the corresponding color-to-color map, then replaced by the contents of that map indexed by the scaled component. That is, the red component is scaled by GL_PIXEL_MAP_R_TO_R_SIZE, then replaced by the contents of GL_PIXEL_MAP_R_TO_R indexed by itself. The green component is scaled by GL_PIXEL_MAP_G_TO_G_SIZE, then replaced by the contents of GL_PIXEL_MAP_G_TO_G indexed by itself. The blue component is scaled by GL_PIXEL_MAP_B_TO_B_SIZE, then replaced by the contents of GL_PIXEL_MAP_B_TO_B indexed by itself. And the alpha component is scaled by GL_PIXEL_MAP_A_TO_A_SIZE, then replaced by the contents of GL_PIXEL_MAP_A_TO_A indexed by itself. All components taken from the maps are then clamped to the range [0,1]. GL_MAP_COLOR is specified with glPixelTransfer. The contents of the various maps are specified with glPixelMap.

If the ARB_imaging extension is supported, each of the four color components may be scaled and biased after transformation by the color matrix. That is, the red component is multiplied by GL_POST_COLOR_MATRIX_RED_SCALE, then added to GL_POST_COLOR_MATRIX_RED_BIAS; the green component is multiplied by GL_POST_COLOR_MATRIX_GREEN_SCALE, then added to GL_POST_COLOR_MATRIX_GREEN_BIAS; the blue component is multiplied by GL_POST_COLOR_MATRIX_BLUE_SCALE, then added to GL_POST_COLOR_MATRIX_BLUE_BIAS; and the alpha component is multiplied by GL_POST_COLOR_MATRIX_ALPHA_SCALE, then added to GL_POST_COLOR_MATRIX_ALPHA_BIAS. After all four color components are scaled and biased, each is clamped to the range [0,1].

Similarly, if the ARB_imaging extension is supported, each of the four color components may be scaled and biased after processing by the enabled convolution filter. That is, the red component is multiplied by GL_POST_CONVOLUTION_RED_SCALE, then added to GL_POST_CONVOLUTION_RED_BIAS; the green component is multiplied by GL_POST_CONVOLUTION_GREEN_SCALE, then added to GL_POST_CONVOLUTION_GREEN_BIAS; the blue component is multiplied by GL_POST_CONVOLUTION_BLUE_SCALE, then added to GL_POST_CONVOLUTION_BLUE_BIAS; and the alpha component is multiplied by GL_POST_CONVOLUTION_ALPHA_SCALE, then added to GL_POST_CONVOLUTION_ALPHA_BIAS. After all four color components are scaled and biased, each is clamped to the range [0,1].

Color index

Each color index is shifted left by GL_INDEX_SHIFT bits; any bits beyond the number of fraction bits carried by the fixed-point index are filled with zeros. If GL_INDEX_SHIFT is negative, the shift is to the right, again zero filled. Then GL_INDEX_OFFSET is added to the index. GL_INDEX_SHIFT and GL_INDEX_OFFSET are specified with glPixelTransfer.

From this point, operation diverges depending on the required format of the resulting pixels. If the resulting pixels are to be written to a color index buffer, or if they are being read back to client memory in GL_COLOR_INDEX format, the pixels continue to be treated as indices. If GL_MAP_COLOR is true, each index is masked by 2^n-1, where n is GL_PIXEL_MAP_I_TO_I_SIZE, then replaced by the contents of GL_PIXEL_MAP_I_TO_I indexed by the masked value. GL_MAP_COLOR is specified with glPixelTransfer. The contents of the index map is specified with glPixelMap.

If the resulting pixels are to be written to an RGBA color buffer, or if they are read back to client memory in a format other than GL_COLOR_INDEX, the pixels are converted from indices to colors by referencing the four maps GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and GL_PIXEL_MAP_I_TO_A. Before being dereferenced, the index is masked by 2^n-1, where n is GL_PIXEL_MAP_I_TO_R_SIZE for the red map, GL_PIXEL_MAP_I_TO_G_SIZE for the green map, GL_PIXEL_MAP_I_TO_B_SIZE for the blue map, and GL_PIXEL_MAP_I_TO_A_SIZE for the alpha map. All components taken from the maps are then clamped to the range [0,1]. The contents of the four maps is specified with glPixelMap.

Depth

Each depth value is multiplied by GL_DEPTH_SCALE, added to GL_DEPTH_BIAS, then clamped to the range [0,1].

Stencil

Each index is shifted GL_INDEX_SHIFT bits just as a color index is, then added to GL_INDEX_OFFSET. If GL_MAP_STENCIL is true, each index is masked by 2^n-1, where n is GL_PIXEL_MAP_S_TO_S_SIZE, then replaced by the contents of GL_PIXEL_MAP_S_TO_S indexed by the masked value.

The following table gives the type, initial value, and range of valid values for each of the pixel transfer parameters that are set with glPixelTransfer.

pname: Type, Initial Value, Valid Range
GL_MAP_COLOR: boolean , false , true/false
GL_MAP_STENCIL: boolean , false , true/false
GL_INDEX_SHIFT: integer , 0 , (-â,â)
GL_INDEX_OFFSET: integer , 0 , (-â,â)
GL_RED_SCALE: float , 1 , (-â,â)
GL_GREEN_SCALE: float , 1 , (-â,â)
GL_BLUE_SCALE: float , 1 , (-â,â)
GL_ALPHA_SCALE: float , 1 , (-â,â)
GL_DEPTH_SCALE: float , 1 , (-â,â)
GL_RED_BIAS: float , 0 , (-â,â)
GL_GREEN_BIAS: float , 0 , (-â,â)
GL_BLUE_BIAS: float , 0 , (-â,â)
GL_ALPHA_BIAS: float , 0 , (-â,â)
GL_DEPTH_BIAS: float , 0 , (-â,â)
GL_POST_COLOR_MATRIX_RED_SCALE: float , 1 , (-â,â)
GL_POST_COLOR_MATRIX_GREEN_SCALE: float , 1 , (-â,â)
GL_POST_COLOR_MATRIX_BLUE_SCALE: float , 1 , (-â,â)
GL_POST_COLOR_MATRIX_ALPHA_SCALE: float , 1 , (-â,â)
GL_POST_COLOR_MATRIX_RED_BIAS: float , 0 , (-â,â)
GL_POST_COLOR_MATRIX_GREEN_BIAS: float , 0 , (-â,â)
GL_POST_COLOR_MATRIX_BLUE_BIAS: float , 0 , (-â,â)
GL_POST_COLOR_MATRIX_ALPHA_BIAS: float , 0 , (-â,â)
GL_POST_CONVOLUTION_RED_SCALE: float , 1 , (-â,â)
GL_POST_CONVOLUTION_GREEN_SCALE: float , 1 , (-â,â)
GL_POST_CONVOLUTION_BLUE_SCALE: float , 1 , (-â,â)
GL_POST_CONVOLUTION_ALPHA_SCALE: float , 1 , (-â,â)
GL_POST_CONVOLUTION_RED_BIAS: float , 0 , (-â,â)
GL_POST_CONVOLUTION_GREEN_BIAS: float , 0 , (-â,â)
GL_POST_CONVOLUTION_BLUE_BIAS: float , 0 , (-â,â)
GL_POST_CONVOLUTION_ALPHA_BIAS: float , 0 , (-â,â)

glPixelTransferf can be used to set any pixel transfer parameter. If the parameter type is boolean, 0 implies false and any other value implies true. If pname is an integer parameter, param is rounded to the nearest integer.

Likewise, glPixelTransferi can be used to set any of the pixel transfer parameters. Boolean parameters are set to false if param is 0 and to true otherwise. param is converted to floating point before being assigned to real-valued parameters.

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_OPERATION is generated if glPixelTransfer is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPixelZoom xfactor yfactor

Specify the pixel zoom factors.

xfactor
yfactor: Specify the x and y zoom factors for pixel write operations.

glPixelZoom specifies values for the x and y zoom factors. During the execution of glDrawPixels or glCopyPixels, if (xr, yr) is the current raster position, and a given element is in the mth row and nth column of the pixel rectangle, then pixels whose centers are in the rectangle with corners at

(xr+nÂ·xfactor, yr+mÂ·yfactor)

(xr+(n+1,)Â·xfactor, yr+(m+1,)Â·yfactor)

are candidates for replacement. Any pixel whose center lies on the bottom or left edge of this rectangular region is also modified.

Pixel zoom factors are not limited to positive values. Negative zoom factors reflect the resulting image about the current raster position.

GL_INVALID_OPERATION is generated if glPixelZoom is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPointParameterf pname param

Function: void glPointParameteri pname param

Function: void glPointParameterfv pname params

Function: void glPointParameteriv pname params

Specify point parameters.

pname: Specifies a single-valued point parameter. GL_POINT_SIZE_MIN, GL_POINT_SIZE_MAX, GL_POINT_FADE_THRESHOLD_SIZE, and GL_POINT_SPRITE_COORD_ORIGIN are accepted.
param: Specifies the value that pname will be set to.

The following values are accepted for pname:

GL_POINT_SIZE_MIN: params is a single floating-point value that specifies the minimum point size. The default value is 0.0.
GL_POINT_SIZE_MAX: params is a single floating-point value that specifies the maximum point size. The default value is 1.0.
GL_POINT_FADE_THRESHOLD_SIZE: params is a single floating-point value that specifies the threshold value to which point sizes are clamped if they exceed the specified value. The default value is 1.0.
GL_POINT_DISTANCE_ATTENUATION: params is an array of three floating-point values that specify the coefficients used for scaling the computed point size. The default values are (1,00).
GL_POINT_SPRITE_COORD_ORIGIN: params is a single enum specifying the point sprite texture coordinate origin, either GL_LOWER_LEFT or GL_UPPER_LEFT. The default value is GL_UPPER_LEFT.

GL_INVALID_VALUE is generated If the value specified for GL_POINT_SIZE_MIN, GL_POINT_SIZE_MAX, or GL_POINT_FADE_THRESHOLD_SIZE is less than zero.

GL_INVALID_ENUM is generated If the value specified for GL_POINT_SPRITE_COORD_ORIGIN is not GL_LOWER_LEFT or GL_UPPER_LEFT.

If the value for GL_POINT_SIZE_MIN is greater than GL_POINT_SIZE_MAX, the point size after clamping is undefined, but no error is generated.

Function: void glPointSize size

Specify the diameter of rasterized points.

size: Specifies the diameter of rasterized points. The initial value is 1.

glPointSize specifies the rasterized diameter of both aliased and antialiased points. Using a point size other than 1 has different effects, depending on whether point antialiasing is enabled. To enable and disable point antialiasing, call glEnable and glDisable with argument GL_POINT_SMOOTH. Point antialiasing is initially disabled.

The specified point size is multiplied with a distance attenuation factor and clamped to the specified point size range, and further clamped to the implementation-dependent point size range to produce the derived point size using

pointSize=clampâ¢(sizeÃâ(1/a+bÃd+cÃd^2,,,),,)

where d is the eye-coordinate distance from the eye to the vertex, and a, b, and c are the distance attenuation coefficients (see glPointParameter).

If multisampling is disabled, the computed point size is used as the point’s width.

If multisampling is enabled, the point may be faded by modifying the point alpha value (see glSampleCoverage) instead of allowing the point width to go below a given threshold (see glPointParameter). In this case, the width is further modified in the following manner:

pointWidth={(pointSize), (threshold)â¢(pointSize>=threshold), (otherwise),

The point alpha value is modified by computing:

pointAlpha={(1), ((pointSize/threshold,)^2)â¢(pointSize>=threshold), (otherwise),

If point antialiasing is disabled, the actual size is determined by rounding the supplied size to the nearest integer. (If the rounding results in the value 0, it is as if the point size were 1.) If the rounded size is odd, then the center point (x, y) of the pixel fragment that represents the point is computed as

(âx_w,â+.5,ây_w,â+.5)

where w subscripts indicate window coordinates. All pixels that lie within the square grid of the rounded size centered at (x, y) make up the fragment. If the size is even, the center point is

(âx_w+.5,â,ây_w+.5,â)

and the rasterized fragment’s centers are the half-integer window coordinates within the square of the rounded size centered at (x,y). All pixel fragments produced in rasterizing a nonantialiased point are assigned the same associated data, that of the vertex corresponding to the point.

If antialiasing is enabled, then point rasterization produces a fragment for each pixel square that intersects the region lying within the circle having diameter equal to the current point size and centered at the point’s (x_w,y_w). The coverage value for each fragment is the window coordinate area of the intersection of the circular region with the corresponding pixel square. This value is saved and used in the final rasterization step. The data associated with each fragment is the data associated with the point being rasterized.

Not all sizes are supported when point antialiasing is enabled. If an unsupported size is requested, the nearest supported size is used. Only size 1 is guaranteed to be supported; others depend on the implementation. To query the range of supported sizes and the size difference between supported sizes within the range, call glGet with arguments GL_SMOOTH_POINT_SIZE_RANGE and GL_SMOOTH_POINT_SIZE_GRANULARITY. For aliased points, query the supported ranges and granularity with glGet with arguments GL_ALIASED_POINT_SIZE_RANGE.

GL_INVALID_VALUE is generated if size is less than or equal to 0.

GL_INVALID_OPERATION is generated if glPointSize is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPolygonMode face mode

Select a polygon rasterization mode.

face: Specifies the polygons that mode applies to. Must be GL_FRONT for front-facing polygons, GL_BACK for back-facing polygons, or GL_FRONT_AND_BACK for front- and back-facing polygons.
mode: Specifies how polygons will be rasterized. Accepted values are GL_POINT, GL_LINE, and GL_FILL. The initial value is GL_FILL for both front- and back-facing polygons.

glPolygonMode controls the interpretation of polygons for rasterization. face describes which polygons mode applies to: front-facing polygons (GL_FRONT), back-facing polygons (GL_BACK), or both (GL_FRONT_AND_BACK). The polygon mode affects only the final rasterization of polygons. In particular, a polygon’s vertices are lit and the polygon is clipped and possibly culled before these modes are applied.

Three modes are defined and can be specified in mode:

GL_POINT: Polygon vertices that are marked as the start of a boundary edge are drawn as points. Point attributes such as GL_POINT_SIZE and GL_POINT_SMOOTH control the rasterization of the points. Polygon rasterization attributes other than GL_POLYGON_MODE have no effect.
GL_LINE: Boundary edges of the polygon are drawn as line segments. They are treated as connected line segments for line stippling; the line stipple counter and pattern are not reset between segments (see glLineStipple). Line attributes such as GL_LINE_WIDTH and GL_LINE_SMOOTH control the rasterization of the lines. Polygon rasterization attributes other than GL_POLYGON_MODE have no effect.
GL_FILL: The interior of the polygon is filled. Polygon attributes such as GL_POLYGON_STIPPLE and GL_POLYGON_SMOOTH control the rasterization of the polygon.

GL_INVALID_ENUM is generated if either face or mode is not an accepted value.

GL_INVALID_OPERATION is generated if glPolygonMode is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPolygonOffset factor units

Set the scale and units used to calculate depth values.

factor: Specifies a scale factor that is used to create a variable depth offset for each polygon. The initial value is 0.
units: Is multiplied by an implementation-specific value to create a constant depth offset. The initial value is 0.

When GL_POLYGON_OFFSET_FILL, GL_POLYGON_OFFSET_LINE, or GL_POLYGON_OFFSET_POINT is enabled, each fragment’s depth value will be offset after it is interpolated from the depth values of the appropriate vertices. The value of the offset is factorÃDZ+rÃunits, where DZ is a measurement of the change in depth relative to the screen area of the polygon, and r is the smallest value that is guaranteed to produce a resolvable offset for a given implementation. The offset is added before the depth test is performed and before the value is written into the depth buffer.

glPolygonOffset is useful for rendering hidden-line images, for applying decals to surfaces, and for rendering solids with highlighted edges.

GL_INVALID_OPERATION is generated if glPolygonOffset is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPolygonStipple pattern

Set the polygon stippling pattern.

pattern: Specifies a pointer to a 32Ã32 stipple pattern that will be unpacked from memory in the same way that glDrawPixels unpacks pixels.

Polygon stippling, like line stippling (see glLineStipple), masks out certain fragments produced by rasterization, creating a pattern. Stippling is independent of polygon antialiasing.

pattern is a pointer to a 32Ã32 stipple pattern that is stored in memory just like the pixel data supplied to a glDrawPixels call with height and width both equal to 32, a pixel format of GL_COLOR_INDEX, and data type of GL_BITMAP. That is, the stipple pattern is represented as a 32Ã32 array of 1-bit color indices packed in unsigned bytes. glPixelStore parameters like GL_UNPACK_SWAP_BYTES and GL_UNPACK_LSB_FIRST affect the assembling of the bits into a stipple pattern. Pixel transfer operations (shift, offset, pixel map) are not applied to the stipple image, however.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a stipple pattern is specified, pattern is treated as a byte offset into the buffer object’s data store.

To enable and disable polygon stippling, call glEnable and glDisable with argument GL_POLYGON_STIPPLE. Polygon stippling is initially disabled. If it’s enabled, a rasterized polygon fragment with window coordinates x_w and y_w is sent to the next stage of the GL if and only if the (x_w%32)th bit in the (y_w%32)th row of the stipple pattern is 1 (one). When polygon stippling is disabled, it is as if the stipple pattern consists of all 1’s.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glPolygonStipple is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPrioritizeTextures n textures priorities

Set texture residence priority.

n: Specifies the number of textures to be prioritized.
textures: Specifies an array containing the names of the textures to be prioritized.
priorities: Specifies an array containing the texture priorities. A priority given in an element of priorities applies to the texture named by the corresponding element of textures.

glPrioritizeTextures assigns the n texture priorities given in priorities to the n textures named in textures.

The GL establishes a “working set” of textures that are resident in texture memory. These textures may be bound to a texture target much more efficiently than textures that are not resident. By specifying a priority for each texture, glPrioritizeTextures allows applications to guide the GL implementation in determining which textures should be resident.

The priorities given in priorities are clamped to the range [0,1] before they are assigned. 0 indicates the lowest priority; textures with priority 0 are least likely to be resident. 1 indicates the highest priority; textures with priority 1 are most likely to be resident. However, textures are not guaranteed to be resident until they are used.

glPrioritizeTextures silently ignores attempts to prioritize texture 0 or any texture name that does not correspond to an existing texture.

glPrioritizeTextures does not require that any of the textures named by textures be bound to a texture target. glTexParameter may also be used to set a texture’s priority, but only if the texture is currently bound. This is the only way to set the priority of a default texture.

GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_OPERATION is generated if glPrioritizeTextures is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPushAttrib mask

Function: void glPopAttrib

Push and pop the server attribute stack.

mask: Specifies a mask that indicates which attributes to save. Values for mask are listed below.

glPushAttrib takes one argument, a mask that indicates which groups of state variables to save on the attribute stack. Symbolic constants are used to set bits in the mask. mask is typically constructed by specifying the bitwise-or of several of these constants together. The special mask GL_ALL_ATTRIB_BITS can be used to save all stackable states.

The symbolic mask constants and their associated GL state are as follows (the second column lists which attributes are saved):

GL_ACCUM_BUFFER_BIT: Accumulation buffer clear value
GL_COLOR_BUFFER_BIT: GL_ALPHA_TEST enable bit
.: Alpha test function and reference value
.: GL_BLEND enable bit
.: Blending source and destination functions
.: Constant blend color
.: Blending equation
.: GL_DITHER enable bit
.: GL_DRAW_BUFFER setting
.: GL_COLOR_LOGIC_OP enable bit
.: GL_INDEX_LOGIC_OP enable bit
.: Logic op function
.: Color mode and index mode clear values
.: Color mode and index mode writemasks
GL_CURRENT_BIT: Current RGBA color
.: Current color index
.: Current normal vector
.: Current texture coordinates
.: Current raster position
.: GL_CURRENT_RASTER_POSITION_VALID flag
.: RGBA color associated with current raster position
.: Color index associated with current raster position
.: Texture coordinates associated with current raster position
.: GL_EDGE_FLAG flag
GL_DEPTH_BUFFER_BIT: GL_DEPTH_TEST enable bit
.: Depth buffer test function
.: Depth buffer clear value
.: GL_DEPTH_WRITEMASK enable bit
GL_ENABLE_BIT: GL_ALPHA_TEST flag
.: GL_AUTO_NORMAL flag
.: GL_BLEND flag
.: Enable bits for the user-definable clipping planes
.: GL_COLOR_MATERIAL
.: GL_CULL_FACE flag
.: GL_DEPTH_TEST flag
.: GL_DITHER flag
.: GL_FOG flag
.: GL_LIGHTi where 0 <= i < GL_MAX_LIGHTS
.: GL_LIGHTING flag
.: GL_LINE_SMOOTH flag
.: GL_LINE_STIPPLE flag
.: GL_COLOR_LOGIC_OP flag
.: GL_INDEX_LOGIC_OP flag
.: GL_MAP1_x where x is a map type
.: GL_MAP2_x where x is a map type
.: GL_MULTISAMPLE flag
.: GL_NORMALIZE flag
.: GL_POINT_SMOOTH flag
.: GL_POLYGON_OFFSET_LINE flag
.: GL_POLYGON_OFFSET_FILL flag
.: GL_POLYGON_OFFSET_POINT flag
.: GL_POLYGON_SMOOTH flag
.: GL_POLYGON_STIPPLE flag
.: GL_SAMPLE_ALPHA_TO_COVERAGE flag
.: GL_SAMPLE_ALPHA_TO_ONE flag
.: GL_SAMPLE_COVERAGE flag
.: GL_SCISSOR_TEST flag
.: GL_STENCIL_TEST flag
.: GL_TEXTURE_1D flag
.: GL_TEXTURE_2D flag
.: GL_TEXTURE_3D flag
.: Flags GL_TEXTURE_GEN_x where x is S, T, R, or Q
GL_EVAL_BIT: GL_MAP1_x enable bits, where x is a map type
.: GL_MAP2_x enable bits, where x is a map type
.: 1D grid endpoints and divisions
.: 2D grid endpoints and divisions
.: GL_AUTO_NORMAL enable bit
GL_FOG_BIT: GL_FOG enable bit
.: Fog color
.: Fog density
.: Linear fog start
.: Linear fog end
.: Fog index
.: GL_FOG_MODE value
GL_HINT_BIT: GL_PERSPECTIVE_CORRECTION_HINT setting
.: GL_POINT_SMOOTH_HINT setting
.: GL_LINE_SMOOTH_HINT setting
.: GL_POLYGON_SMOOTH_HINT setting
.: GL_FOG_HINT setting
.: GL_GENERATE_MIPMAP_HINT setting
.: GL_TEXTURE_COMPRESSION_HINT setting
GL_LIGHTING_BIT: GL_COLOR_MATERIAL enable bit
.: GL_COLOR_MATERIAL_FACE value
.: Color material parameters that are tracking the current color
.: Ambient scene color
.: GL_LIGHT_MODEL_LOCAL_VIEWER value
.: GL_LIGHT_MODEL_TWO_SIDE setting
.: GL_LIGHTING enable bit
.: Enable bit for each light
.: Ambient, diffuse, and specular intensity for each light
.: Direction, position, exponent, and cutoff angle for each light
.: Constant, linear, and quadratic attenuation factors for each light
.: Ambient, diffuse, specular, and emissive color for each material
.: Ambient, diffuse, and specular color indices for each material
.: Specular exponent for each material
.: GL_SHADE_MODEL setting
GL_LINE_BIT: GL_LINE_SMOOTH flag
.: GL_LINE_STIPPLE enable bit
.: Line stipple pattern and repeat counter
.: Line width
GL_LIST_BIT: GL_LIST_BASE setting
GL_MULTISAMPLE_BIT: GL_MULTISAMPLE flag
.: GL_SAMPLE_ALPHA_TO_COVERAGE flag
.: GL_SAMPLE_ALPHA_TO_ONE flag
.: GL_SAMPLE_COVERAGE flag
.: GL_SAMPLE_COVERAGE_VALUE value
.: GL_SAMPLE_COVERAGE_INVERT value
GL_PIXEL_MODE_BIT: GL_RED_BIAS and GL_RED_SCALE settings
.: GL_GREEN_BIAS and GL_GREEN_SCALE values
.: GL_BLUE_BIAS and GL_BLUE_SCALE
.: GL_ALPHA_BIAS and GL_ALPHA_SCALE
.: GL_DEPTH_BIAS and GL_DEPTH_SCALE
.: GL_INDEX_OFFSET and GL_INDEX_SHIFT values
.: GL_MAP_COLOR and GL_MAP_STENCIL flags
.: GL_ZOOM_X and GL_ZOOM_Y factors
.: GL_READ_BUFFER setting
GL_POINT_BIT: GL_POINT_SMOOTH flag
.: Point size
GL_POLYGON_BIT: GL_CULL_FACE enable bit
.: GL_CULL_FACE_MODE value
.: GL_FRONT_FACE indicator
.: GL_POLYGON_MODE setting
.: GL_POLYGON_SMOOTH flag
.: GL_POLYGON_STIPPLE enable bit
.: GL_POLYGON_OFFSET_FILL flag
.: GL_POLYGON_OFFSET_LINE flag
.: GL_POLYGON_OFFSET_POINT flag
.: GL_POLYGON_OFFSET_FACTOR
.: GL_POLYGON_OFFSET_UNITS
GL_POLYGON_STIPPLE_BIT: Polygon stipple image
GL_SCISSOR_BIT: GL_SCISSOR_TEST flag
.: Scissor box
GL_STENCIL_BUFFER_BIT: GL_STENCIL_TEST enable bit
.: Stencil function and reference value
.: Stencil value mask
.: Stencil fail, pass, and depth buffer pass actions
.: Stencil buffer clear value
.: Stencil buffer writemask
GL_TEXTURE_BIT: Enable bits for the four texture coordinates
.: Border color for each texture image
.: Minification function for each texture image
.: Magnification function for each texture image
.: Texture coordinates and wrap mode for each texture image
.: Color and mode for each texture environment
.: Enable bits GL_TEXTURE_GEN_x, x is S, T, R, and Q
.: GL_TEXTURE_GEN_MODE setting for S, T, R, and Q
.: glTexGen plane equations for S, T, R, and Q
.: Current texture bindings (for example, GL_TEXTURE_BINDING_2D)
GL_TRANSFORM_BIT: Coefficients of the six clipping planes
.: Enable bits for the user-definable clipping planes
.: GL_MATRIX_MODE value
.: GL_NORMALIZE flag
.: GL_RESCALE_NORMAL flag
GL_VIEWPORT_BIT: Depth range (near and far)
.: Viewport origin and extent

glPopAttrib restores the values of the state variables saved with the last glPushAttrib command. Those not saved are left unchanged.

It is an error to push attributes onto a full stack or to pop attributes off an empty stack. In either case, the error flag is set and no other change is made to GL state.

Initially, the attribute stack is empty.

GL_STACK_OVERFLOW is generated if glPushAttrib is called while the attribute stack is full.

GL_STACK_UNDERFLOW is generated if glPopAttrib is called while the attribute stack is empty.

GL_INVALID_OPERATION is generated if glPushAttrib or glPopAttrib is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPushClientAttrib mask

Function: void glPopClientAttrib

Push and pop the client attribute stack.

mask: Specifies a mask that indicates which attributes to save. Values for mask are listed below.

glPushClientAttrib takes one argument, a mask that indicates which groups of client-state variables to save on the client attribute stack. Symbolic constants are used to set bits in the mask. mask is typically constructed by specifying the bitwise-or of several of these constants together. The special mask GL_CLIENT_ALL_ATTRIB_BITS can be used to save all stackable client state.

The symbolic mask constants and their associated GL client state are as follows (the second column lists which attributes are saved):

GL_CLIENT_PIXEL_STORE_BIT Pixel storage modes GL_CLIENT_VERTEX_ARRAY_BIT Vertex arrays (and enables)

glPopClientAttrib restores the values of the client-state variables saved with the last glPushClientAttrib. Those not saved are left unchanged.

It is an error to push attributes onto a full client attribute stack or to pop attributes off an empty stack. In either case, the error flag is set, and no other change is made to GL state.

Initially, the client attribute stack is empty.

GL_STACK_OVERFLOW is generated if glPushClientAttrib is called while the attribute stack is full.

GL_STACK_UNDERFLOW is generated if glPopClientAttrib is called while the attribute stack is empty.

Function: void glPushMatrix

Function: void glPopMatrix

Push and pop the current matrix stack.

There is a stack of matrices for each of the matrix modes. In GL_MODELVIEW mode, the stack depth is at least 32. In the other modes, GL_COLOR, GL_PROJECTION, and GL_TEXTURE, the depth is at least 2. The current matrix in any mode is the matrix on the top of the stack for that mode.

glPushMatrix pushes the current matrix stack down by one, duplicating the current matrix. That is, after a glPushMatrix call, the matrix on top of the stack is identical to the one below it.

glPopMatrix pops the current matrix stack, replacing the current matrix with the one below it on the stack.

Initially, each of the stacks contains one matrix, an identity matrix.

It is an error to push a full matrix stack or to pop a matrix stack that contains only a single matrix. In either case, the error flag is set and no other change is made to GL state.

GL_STACK_OVERFLOW is generated if glPushMatrix is called while the current matrix stack is full.

GL_STACK_UNDERFLOW is generated if glPopMatrix is called while the current matrix stack contains only a single matrix.

GL_INVALID_OPERATION is generated if glPushMatrix or glPopMatrix is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glPushName name

Function: void glPopName

Push and pop the name stack.

name: Specifies a name that will be pushed onto the name stack.

The name stack is used during selection mode to allow sets of rendering commands to be uniquely identified. It consists of an ordered set of unsigned integers and is initially empty.

glPushName causes name to be pushed onto the name stack. glPopName pops one name off the top of the stack.

The maximum name stack depth is implementation-dependent; call GL_MAX_NAME_STACK_DEPTH to find out the value for a particular implementation. It is an error to push a name onto a full stack or to pop a name off an empty stack. It is also an error to manipulate the name stack between the execution of glBegin and the corresponding execution of glEnd. In any of these cases, the error flag is set and no other change is made to GL state.

The name stack is always empty while the render mode is not GL_SELECT. Calls to glPushName or glPopName while the render mode is not GL_SELECT are ignored.

GL_STACK_OVERFLOW is generated if glPushName is called while the name stack is full.

GL_STACK_UNDERFLOW is generated if glPopName is called while the name stack is empty.

GL_INVALID_OPERATION is generated if glPushName or glPopName is executed between a call to glBegin and the corresponding call to glEnd.

Function: void glRasterPos2s x y

Function: void glRasterPos2i x y

Function: void glRasterPos2f x y

Function: void glRasterPos2d x y

Function: void glRasterPos3s x y z

Function: void glRasterPos3i x y z

Function: void glRasterPos3f x y z

Function: void glRasterPos3d x y z

Function: void glRasterPos4s x y z w

Function: void glRasterPos4i x y z w

Function: void glRasterPos4f x y z w

Function: void glRasterPos4d x y z w

Function: void glRasterPos2sv v

Function: void glRasterPos2iv v

Function: void glRasterPos2fv v

Function: void glRasterPos2dv v

Function: void glRasterPos3sv v

Function: void glRasterPos3iv v

Function: void glRasterPos3fv v

Function: void glRasterPos3dv v

Function: void glRasterPos4sv v

Function: void glRasterPos4iv v

Function: void glRasterPos4fv v

Function: void glRasterPos4dv v

Specify the raster position for pixel operations.

x
y
z
w: Specify the x, y, z, and w object coordinates (if present) for the raster position.

The GL maintains a 3D position in window coordinates. This position, called the raster position, is used to position pixel and bitmap write operations. It is maintained with subpixel accuracy. See glBitmap, glDrawPixels, and glCopyPixels.

The current raster position consists of three window coordinates (x, y, z), a clip coordinate value (w), an eye coordinate distance, a valid bit, and associated color data and texture coordinates. The w coordinate is a clip coordinate, because w is not projected to window coordinates. glRasterPos4 specifies object coordinates x, y, z, and w explicitly. glRasterPos3 specifies object coordinate x, y, and z explicitly, while w is implicitly set to 1. glRasterPos2 uses the argument values for x and y while implicitly setting z and w to 0 and 1.

The object coordinates presented by glRasterPos are treated just like those of a glVertex command: They are transformed by the current modelview and projection matrices and passed to the clipping stage. If the vertex is not culled, then it is projected and scaled to window coordinates, which become the new current raster position, and the GL_CURRENT_RASTER_POSITION_VALID flag is set. If the vertex is culled, then the valid bit is cleared and the current raster position and associated color and texture coordinates are undefined.

The current raster position also includes some associated color data and texture coordinates. If lighting is enabled, then GL_CURRENT_RASTER_COLOR (in RGBA mode) or GL_CURRENT_RASTER_INDEX (in color index mode) is set to the color produced by the lighting calculation (see glLight, glLightModel, and glShadeModel). If lighting is disabled, current color (in RGBA mode, state variable GL_CURRENT_COLOR) or color index (in color index mode, state variable GL_CURRENT_INDEX) is used to update the current raster color. GL_CURRENT_RASTER_SECONDARY_COLOR (in RGBA mode) is likewise updated.

Likewise, GL_CURRENT_RASTER_TEXTURE_COORDS is updated as a function of GL_CURRENT_TEXTURE_COORDS, based on the texture matrix and the texture generation functions (see glTexGen). Finally, the distance from the origin of the eye coordinate system to the vertex as transformed by only the modelview matrix replaces GL_CURRENT_RASTER_DISTANCE.

Initially, the current raster position is (0, 0, 0, 1), the current raster distance is 0, the valid bit is set, the associated RGBA color is (1, 1, 1, 1), the associated color index is 1, and the associated texture coordinates are (0, 0, 0, 1). In RGBA mode, GL_CURRENT_RASTER_INDEX is always 1; in color index mode, the current raster RGBA color always maintains its initial value.

GL_INVALID_OPERATION is generated if glRasterPos is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glReadBuffer mode

Select a color buffer source for pixels.

mode: Specifies a color buffer. Accepted values are GL_FRONT_LEFT, GL_FRONT_RIGHT, GL_BACK_LEFT, GL_BACK_RIGHT, GL_FRONT, GL_BACK, GL_LEFT, GL_RIGHT, and GL_AUXi, where i is between 0 and the value of GL_AUX_BUFFERS minus 1.

glReadBuffer specifies a color buffer as the source for subsequent glReadPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, and glCopyPixels commands. mode accepts one of twelve or more predefined values. (GL_AUX0 through GL_AUX3 are always defined.) In a fully configured system, GL_FRONT, GL_LEFT, and GL_FRONT_LEFT all name the front left buffer, GL_FRONT_RIGHT and GL_RIGHT name the front right buffer, and GL_BACK_LEFT and GL_BACK name the back left buffer.

Nonstereo double-buffered configurations have only a front left and a back left buffer. Single-buffered configurations have a front left and a front right buffer if stereo, and only a front left buffer if nonstereo. It is an error to specify a nonexistent buffer to glReadBuffer.

mode is initially GL_FRONT in single-buffered configurations and GL_BACK in double-buffered configurations.

GL_INVALID_ENUM is generated if mode is not one of the twelve (or more) accepted values.

GL_INVALID_OPERATION is generated if mode specifies a buffer that does not exist.

GL_INVALID_OPERATION is generated if glReadBuffer is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glReadPixels x y width height format type data

Read a block of pixels from the frame buffer.

x
y: Specify the window coordinates of the first pixel that is read from the frame buffer. This location is the lower left corner of a rectangular block of pixels.
width
height: Specify the dimensions of the pixel rectangle. width and height of one correspond to a single pixel.
format: Specifies the format of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_STENCIL_INDEX, GL_DEPTH_COMPONENT, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: Specifies the data type of the pixel data. Must be one of GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV.
data: Returns the pixel data.

glReadPixels returns pixel data from the frame buffer, starting with the pixel whose lower left corner is at location (x, y), into client memory starting at location data. Several parameters control the processing of the pixel data before it is placed into client memory. These parameters are set with three commands: glPixelStore, glPixelTransfer, and glPixelMap. This reference page describes the effects on glReadPixels of most, but not all of the parameters specified by these three commands.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer) while a block of pixels is requested, data is treated as a byte offset into the buffer object’s data store rather than a pointer to client memory.

When the ARB_imaging extension is supported, the pixel data may be processed by additional operations including color table lookup, color matrix transformations, convolutions, histograms, and minimum and maximum pixel value computations.

glReadPixels returns values from each pixel with lower left corner at (x+i,y+j) for 0<=i<width and 0<=j<height. This pixel is said to be the ith pixel in the jth row. Pixels are returned in row order from the lowest to the highest row, left to right in each row.

format specifies the format for the returned pixel values; accepted values are:

GL_COLOR_INDEX

Color indices are read from the color buffer selected by glReadBuffer. Each index is converted to fixed point, shifted left or right depending on the value and sign of GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET. If GL_MAP_COLOR is GL_TRUE, indices are replaced by their mappings in the table GL_PIXEL_MAP_I_TO_I.

GL_STENCIL_INDEX

Stencil values are read from the stencil buffer. Each index is converted to fixed point, shifted left or right depending on the value and sign of GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET. If GL_MAP_STENCIL is GL_TRUE, indices are replaced by their mappings in the table GL_PIXEL_MAP_S_TO_S.

GL_DEPTH_COMPONENT

Depth values are read from the depth buffer. Each component is converted to floating point such that the minimum depth value maps to 0 and the maximum value maps to 1. Each component is then multiplied by GL_DEPTH_SCALE, added to GL_DEPTH_BIAS, and finally clamped to the range [0,1].

GL_RED

GL_GREEN

GL_BLUE

GL_ALPHA

GL_RGB

GL_BGR

GL_RGBA

GL_BGRA

GL_LUMINANCE

GL_LUMINANCE_ALPHA

Processing differs depending on whether color buffers store color indices or RGBA color components. If color indices are stored, they are read from the color buffer selected by glReadBuffer. Each index is converted to fixed point, shifted left or right depending on the value and sign of GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET. Indices are then replaced by the red, green, blue, and alpha values obtained by indexing the tables GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and GL_PIXEL_MAP_I_TO_A. Each table must be of size 2^n, but n may be different for different tables. Before an index is used to look up a value in a table of size 2^n, it must be masked against 2^n-1.

If RGBA color components are stored in the color buffers, they are read from the color buffer selected by glReadBuffer. Each color component is converted to floating point such that zero intensity maps to 0.0 and full intensity maps to 1.0. Each component is then multiplied by GL_c_SCALE and added to GL_c_BIAS, where c is RED, GREEN, BLUE, or ALPHA. Finally, if GL_MAP_COLOR is GL_TRUE, each component is clamped to the range [0,1], scaled to the size of its corresponding table, and is then replaced by its mapping in the table GL_PIXEL_MAP_c_TO_c, where c is R, G, B, or A.

Unneeded data is then discarded. For example, GL_RED discards the green, blue, and alpha components, while GL_RGB discards only the alpha component. GL_LUMINANCE computes a single-component value as the sum of the red, green, and blue components, and GL_LUMINANCE_ALPHA does the same, while keeping alpha as a second value. The final values are clamped to the range [0,1].

The shift, scale, bias, and lookup factors just described are all specified by glPixelTransfer. The lookup table contents themselves are specified by glPixelMap.

Finally, the indices or components are converted to the proper format, as specified by type. If format is GL_COLOR_INDEX or GL_STENCIL_INDEX and type is not GL_FLOAT, each index is masked with the mask value given in the following table. If type is GL_FLOAT, then each integer index is converted to single-precision floating-point format.

If format is GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA and type is not GL_FLOAT, each component is multiplied by the multiplier shown in the following table. If type is GL_FLOAT, then each component is passed as is (or converted to the client’s single-precision floating-point format if it is different from the one used by the GL).

type: Index Mask, Component Conversion
GL_UNSIGNED_BYTE: 2^8-1, (2^8-1,)â¢c
GL_BYTE: 2^7-1, (2^8-1,)â¢c-1,/2
GL_BITMAP: 1, 1
GL_UNSIGNED_SHORT: 2^16-1, (2^16-1,)â¢c
GL_SHORT: 2^15-1, (2^16-1,)â¢c-1,/2
GL_UNSIGNED_INT: 2^32-1, (2^32-1,)â¢c
GL_INT: 2^31-1, (2^32-1,)â¢c-1,/2
GL_FLOAT: none , c

Return values are placed in memory as follows. If format is GL_COLOR_INDEX, GL_STENCIL_INDEX, GL_DEPTH_COMPONENT, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, or GL_LUMINANCE, a single value is returned and the data for the ith pixel in the jth row is placed in location (j,)â¢width+i. GL_RGB and GL_BGR return three values, GL_RGBA and GL_BGRA return four values, and GL_LUMINANCE_ALPHA returns two values for each pixel, with all values corresponding to a single pixel occupying contiguous space in data. Storage parameters set by glPixelStore, such as GL_PACK_LSB_FIRST and GL_PACK_SWAP_BYTES, affect the way that data is written into memory. See glPixelStore for a description.

GL_INVALID_ENUM is generated if format or type is not an accepted value.

GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX or GL_STENCIL_INDEX.

GL_INVALID_VALUE is generated if either width or height is negative.

GL_INVALID_OPERATION is generated if format is GL_COLOR_INDEX and the color buffers store RGBA color components.

GL_INVALID_OPERATION is generated if format is GL_STENCIL_INDEX and there is no stencil buffer.

GL_INVALID_OPERATION is generated if format is GL_DEPTH_COMPONENT and there is no depth buffer.

The formats GL_BGR, and GL_BGRA and types GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are available only if the GL version is 1.2 or greater.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and data is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

GL_INVALID_OPERATION is generated if glReadPixels is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glRectd x1 y1 x2 y2

Function: void glRectf x1 y1 x2 y2

Function: void glRecti x1 y1 x2 y2

Function: void glRects x1 y1 x2 y2

Function: void glRectdv v1 v2

Function: void glRectfv v1 v2

Function: void glRectiv v1 v2

Function: void glRectsv v1 v2

Draw a rectangle.

x1
y1: Specify one vertex of a rectangle.
x2
y2: Specify the opposite vertex of the rectangle.

glRect supports efficient specification of rectangles as two corner points. Each rectangle command takes four arguments, organized either as two consecutive pairs of (x,y) coordinates or as two pointers to arrays, each containing an (x,y) pair. The resulting rectangle is defined in the z=0 plane.

glRect(x1, y1, x2, y2) is exactly equivalent to the following sequence: Note that if the second vertex is above and to the right of the first vertex, the rectangle is constructed with a counterclockwise winding.

glBegin(GL_POLYGON);
glVertex2(x1, y1);
glVertex2(x2, y1);
glVertex2(x2, y2);
glVertex2(x1, y2);
glEnd();

GL_INVALID_OPERATION is generated if glRect is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: GLint glRenderMode mode

Set rasterization mode.

mode: Specifies the rasterization mode. Three values are accepted: GL_RENDER, GL_SELECT, and GL_FEEDBACK. The initial value is GL_RENDER.

glRenderMode sets the rasterization mode. It takes one argument, mode, which can assume one of three predefined values:

GL_RENDER: Render mode. Primitives are rasterized, producing pixel fragments, which are written into the frame buffer. This is the normal mode and also the default mode.
GL_SELECT: Selection mode. No pixel fragments are produced, and no change to the frame buffer contents is made. Instead, a record of the names of primitives that would have been drawn if the render mode had been GL_RENDER is returned in a select buffer, which must be created (see glSelectBuffer) before selection mode is entered.
GL_FEEDBACK: Feedback mode. No pixel fragments are produced, and no change to the frame buffer contents is made. Instead, the coordinates and attributes of vertices that would have been drawn if the render mode had been GL_RENDER is returned in a feedback buffer, which must be created (see glFeedbackBuffer) before feedback mode is entered.

The return value of glRenderMode is determined by the render mode at the time glRenderMode is called, rather than by mode. The values returned for the three render modes are as follows:

GL_RENDER: 0.
GL_SELECT: The number of hit records transferred to the select buffer.
GL_FEEDBACK: The number of values (not vertices) transferred to the feedback buffer.

See the glSelectBuffer and glFeedbackBuffer reference pages for more details concerning selection and feedback operation.

GL_INVALID_ENUM is generated if mode is not one of the three accepted values.

GL_INVALID_OPERATION is generated if glSelectBuffer is called while the render mode is GL_SELECT, or if glRenderMode is called with argument GL_SELECT before glSelectBuffer is called at least once.

GL_INVALID_OPERATION is generated if glRenderMode is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glResetHistogram target

Reset histogram table entries to zero.

target: Must be GL_HISTOGRAM.

glResetHistogram resets all the elements of the current histogram table to zero.

GL_INVALID_ENUM is generated if target is not GL_HISTOGRAM.

GL_INVALID_OPERATION is generated if glResetHistogram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glResetMinmax target

Reset minmax table entries to initial values.

target: Must be GL_MINMAX.

glResetMinmax resets the elements of the current minmax table to their initial values: the “maximum” element receives the minimum possible component values, and the “minimum” element receives the maximum possible component values.

GL_INVALID_ENUM is generated if target is not GL_MINMAX.

GL_INVALID_OPERATION is generated if glResetMinmax is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glRotated angle x y z

Function: void glRotatef angle x y z

Multiply the current matrix by a rotation matrix.

angle: Specifies the angle of rotation, in degrees.
x
y
z: Specify the x, y, and z coordinates of a vector, respectively.

glRotate produces a rotation of angle degrees around the vector (x,yz). The current matrix (see glMatrixMode) is multiplied by a rotation matrix with the product replacing the current matrix, as if glMultMatrix were called with the following matrix as its argument:

((x^2â¡(1-c,)+c xâ¢yâ¡(1-c,)-zâ¢s xâ¢zâ¡(1-c,)+yâ¢s 0), (yâ¢xâ¡(1-c,)+zâ¢s y^2â¡(1-c,)+c yâ¢zâ¡(1-c,)-xâ¢s 0), (xâ¢zâ¡(1-c,)-yâ¢s yâ¢zâ¡(1-c,)+xâ¢s z^2â¡(1-c,)+c 0), (0 0 0 1),)

Where c=cosâ¡(angle,), s=sinâ¡(angle,), and â¥(x,yz),â¥=1 (if not, the GL will normalize this vector).

If the matrix mode is either GL_MODELVIEW or GL_PROJECTION, all objects drawn after glRotate is called are rotated. Use glPushMatrix and glPopMatrix to save and restore the unrotated coordinate system.

GL_INVALID_OPERATION is generated if glRotate is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glSampleCoverage value invert

Specify multisample coverage parameters.

value: Specify a single floating-point sample coverage value. The value is clamped to the range [0,1]. The initial value is 1.0.
invert: Specify a single boolean value representing if the coverage masks should be inverted. GL_TRUE and GL_FALSE are accepted. The initial value is GL_FALSE.

Multisampling samples a pixel multiple times at various implementation-dependent subpixel locations to generate antialiasing effects. Multisampling transparently antialiases points, lines, polygons, bitmaps, and images if it is enabled.

value is used in constructing a temporary mask used in determining which samples will be used in resolving the final fragment color. This mask is bitwise-anded with the coverage mask generated from the multisampling computation. If the invert flag is set, the temporary mask is inverted (all bits flipped) and then the bitwise-and is computed.

If an implementation does not have any multisample buffers available, or multisampling is disabled, rasterization occurs with only a single sample computing a pixel’s final RGB color.

Provided an implementation supports multisample buffers, and multisampling is enabled, then a pixel’s final color is generated by combining several samples per pixel. Each sample contains color, depth, and stencil information, allowing those operations to be performed on each sample.

GL_INVALID_OPERATION is generated if glSampleCoverage is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glScaled x y z

Function: void glScalef x y z

Multiply the current matrix by a general scaling matrix.

x
y
z: Specify scale factors along the x, y, and z axes, respectively.

glScale produces a nonuniform scaling along the x, y, and z axes. The three parameters indicate the desired scale factor along each of the three axes.

The current matrix (see glMatrixMode) is multiplied by this scale matrix, and the product replaces the current matrix as if glMultMatrix were called with the following matrix as its argument:

((x 0 0 0), (0 y 0 0), (0 0 z 0), (0 0 0 1),)

If the matrix mode is either GL_MODELVIEW or GL_PROJECTION, all objects drawn after glScale is called are scaled.

Use glPushMatrix and glPopMatrix to save and restore the unscaled coordinate system.

GL_INVALID_OPERATION is generated if glScale is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glScissor x y width height

Define the scissor box.

x
y: Specify the lower left corner of the scissor box. Initially (0, 0).
width
height: Specify the width and height of the scissor box. When a GL context is first attached to a window, width and height are set to the dimensions of that window.

glScissor defines a rectangle, called the scissor box, in window coordinates. The first two arguments, x and y, specify the lower left corner of the box. width and height specify the width and height of the box.

To enable and disable the scissor test, call glEnable and glDisable with argument GL_SCISSOR_TEST. The test is initially disabled. While the test is enabled, only pixels that lie within the scissor box can be modified by drawing commands. Window coordinates have integer values at the shared corners of frame buffer pixels. glScissor(0,0,1,1) allows modification of only the lower left pixel in the window, and glScissor(0,0,0,0) doesn’t allow modification of any pixels in the window.

When the scissor test is disabled, it is as though the scissor box includes the entire window.

GL_INVALID_VALUE is generated if either width or height is negative.

GL_INVALID_OPERATION is generated if glScissor is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glSecondaryColorPointer size type stride pointer

Define an array of secondary colors.

size: Specifies the number of components per color. Must be 3.
type: Specifies the data type of each color component in the array. Symbolic constants GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT, GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
stride: Specifies the byte offset between consecutive colors. If stride is 0, the colors are understood to be tightly packed in the array. The initial value is 0.
pointer: Specifies a pointer to the first component of the first color element in the array. The initial value is 0.

glSecondaryColorPointer specifies the location and data format of an array of color components to use when rendering. size specifies the number of components per color, and must be 3. type specifies the data type of each color component, and stride specifies the byte stride from one color to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays.

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer) while a secondary color array is specified, pointer is treated as a byte offset into the buffer object’s data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as secondary color vertex array client-side state (GL_SECONDARY_COLOR_ARRAY_BUFFER_BINDING).

When a secondary color array is specified, size, type, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable the secondary color array, call glEnableClientState and glDisableClientState with the argument GL_SECONDARY_COLOR_ARRAY. If enabled, the secondary color array is used when glArrayElement, glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, or glDrawRangeElements is called.

GL_INVALID_VALUE is generated if size is not 3.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if stride is negative.

Function: void glSecondaryColor3b red green blue

Function: void glSecondaryColor3s red green blue

Function: void glSecondaryColor3i red green blue

Function: void glSecondaryColor3f red green blue

Function: void glSecondaryColor3d red green blue

Function: void glSecondaryColor3ub red green blue

Function: void glSecondaryColor3us red green blue

Function: void glSecondaryColor3ui red green blue

Function: void glSecondaryColor3bv v

Function: void glSecondaryColor3sv v

Function: void glSecondaryColor3iv v

Function: void glSecondaryColor3fv v

Function: void glSecondaryColor3dv v

Function: void glSecondaryColor3ubv v

Function: void glSecondaryColor3usv v

Function: void glSecondaryColor3uiv v

Set the current secondary color.

red
green
blue: Specify new red, green, and blue values for the current secondary color.

The GL stores both a primary four-valued RGBA color and a secondary four-valued RGBA color (where alpha is always set to 0.0) that is associated with every vertex.

The secondary color is interpolated and applied to each fragment during rasterization when GL_COLOR_SUM is enabled. When lighting is enabled, and GL_SEPARATE_SPECULAR_COLOR is specified, the value of the secondary color is assigned the value computed from the specular term of the lighting computation. Both the primary and secondary current colors are applied to each fragment, regardless of the state of GL_COLOR_SUM, under such conditions. When GL_SEPARATE_SPECULAR_COLOR is specified, the value returned from querying the current secondary color is undefined.

glSecondaryColor3b, glSecondaryColor3s, and glSecondaryColor3i take three signed byte, short, or long integers as arguments. When v is appended to the name, the color commands can take a pointer to an array of such values.

Color values are stored in floating-point format, with unspecified mantissa and exponent sizes. Unsigned integer color components, when specified, are linearly mapped to floating-point values such that the largest representable value maps to 1.0 (full intensity), and 0 maps to 0.0 (zero intensity). Signed integer color components, when specified, are linearly mapped to floating-point values such that the most positive representable value maps to 1.0, and the most negative representable value maps to -1.0. (Note that this mapping does not convert 0 precisely to 0.0). Floating-point values are mapped directly.

Function: void glSelectBuffer size buffer

Establish a buffer for selection mode values.

size: Specifies the size of buffer.
buffer: Returns the selection data.

glSelectBuffer has two arguments: buffer is a pointer to an array of unsigned integers, and size indicates the size of the array. buffer returns values from the name stack (see glInitNames, glLoadName, glPushName) when the rendering mode is GL_SELECT (see glRenderMode). glSelectBuffer must be issued before selection mode is enabled, and it must not be issued while the rendering mode is GL_SELECT.

A programmer can use selection to determine which primitives are drawn into some region of a window. The region is defined by the current modelview and perspective matrices.

In selection mode, no pixel fragments are produced from rasterization. Instead, if a primitive or a raster position intersects the clipping volume defined by the viewing frustum and the user-defined clipping planes, this primitive causes a selection hit. (With polygons, no hit occurs if the polygon is culled.) When a change is made to the name stack, or when glRenderMode is called, a hit record is copied to buffer if any hits have occurred since the last such event (name stack change or glRenderMode call). The hit record consists of the number of names in the name stack at the time of the event, followed by the minimum and maximum depth values of all vertices that hit since the previous event, followed by the name stack contents, bottom name first.

Depth values (which are in the range [0,1]) are multiplied by 2^32-1, before being placed in the hit record.

An internal index into buffer is reset to 0 whenever selection mode is entered. Each time a hit record is copied into buffer, the index is incremented to point to the cell just past the end of the block of names\(emthat is, to the next available cell If the hit record is larger than the number of remaining locations in buffer, as much data as can fit is copied, and the overflow flag is set. If the name stack is empty when a hit record is copied, that record consists of 0 followed by the minimum and maximum depth values.

To exit selection mode, call glRenderMode with an argument other than GL_SELECT. Whenever glRenderMode is called while the render mode is GL_SELECT, it returns the number of hit records copied to buffer, resets the overflow flag and the selection buffer pointer, and initializes the name stack to be empty. If the overflow bit was set when glRenderMode was called, a negative hit record count is returned.

GL_INVALID_VALUE is generated if size is negative.

GL_INVALID_OPERATION is generated if glSelectBuffer is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glSeparableFilter2D target internalformat width height format type row column

Define a separable two-dimensional convolution filter.

target: Must be GL_SEPARABLE_2D.
internalformat: The internal format of the convolution filter kernel. The allowable values are GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
width: The number of elements in the pixel array referenced by row. (This is the width of the separable filter kernel.)
height: The number of elements in the pixel array referenced by column. (This is the height of the separable filter kernel.)
format: The format of the pixel data in row and column. The allowable values are GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_INTENSITY, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: The type of the pixel data in row and column. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
row: Pointer to a one-dimensional array of pixel data that is processed to build the row filter kernel.
column: Pointer to a one-dimensional array of pixel data that is processed to build the column filter kernel.

glSeparableFilter2D builds a two-dimensional separable convolution filter kernel from two arrays of pixels.

The pixel arrays specified by (width, format, type, row) and (height, format, type, column) are processed just as if they had been passed to glDrawPixels, but processing stops after the final expansion to RGBA is completed.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a convolution filter is specified, row and column are treated as byte offsets into the buffer object’s data store.

Next, the R, G, B, and A components of all pixels in both arrays are scaled by the four separable 2D GL_CONVOLUTION_FILTER_SCALE parameters and biased by the four separable 2D GL_CONVOLUTION_FILTER_BIAS parameters. (The scale and bias parameters are set by glConvolutionParameter using the GL_SEPARABLE_2D target and the names GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS. The parameters themselves are vectors of four values that are applied to red, green, blue, and alpha, in that order.) The R, G, B, and A values are not clamped to [0,1] at any time during this process.

Internal Format: Red, Green, Blue, Alpha, Luminance, Intensity
GL_LUMINANCE: , , , , R ,
GL_LUMINANCE_ALPHA: , , , A , R ,
GL_INTENSITY: , , , , , R
GL_RGB: R , G , B , , ,
GL_RGBA: R , G , B , A , ,

The red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are stored in floating-point rather than integer format. They form two one-dimensional filter kernel images. The row image is indexed by coordinate i starting at zero and increasing from left to right. Each location in the row image is derived from element i of row. The column image is indexed by coordinate j starting at zero and increasing from bottom to top. Each location in the column image is derived from element j of column.

GL_INVALID_ENUM is generated if target is not GL_SEPARABLE_2D.

GL_INVALID_ENUM is generated if internalformat is not one of the allowable values.

GL_INVALID_ENUM is generated if format is not one of the allowable values.

GL_INVALID_ENUM is generated if type is not one of the allowable values.

GL_INVALID_VALUE is generated if height is less than zero or greater than the maximum supported value. This value may be queried with glGetConvolutionParameter using target GL_SEPARABLE_2D and name GL_MAX_CONVOLUTION_HEIGHT.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and row or column is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

GL_INVALID_OPERATION is generated if glSeparableFilter2D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glShadeModel mode

Select flat or smooth shading.

mode: Specifies a symbolic value representing a shading technique. Accepted values are GL_FLAT and GL_SMOOTH. The initial value is GL_SMOOTH.

GL primitives can have either flat or smooth shading. Smooth shading, the default, causes the computed colors of vertices to be interpolated as the primitive is rasterized, typically assigning different colors to each resulting pixel fragment. Flat shading selects the computed color of just one vertex and assigns it to all the pixel fragments generated by rasterizing a single primitive. In either case, the computed color of a vertex is the result of lighting if lighting is enabled, or it is the current color at the time the vertex was specified if lighting is disabled.

Flat and smooth shading are indistinguishable for points. Starting when glBegin is issued and counting vertices and primitives from 1, the GL gives each flat-shaded line segment i the computed color of vertex i+1, its second vertex. Counting similarly from 1, the GL gives each flat-shaded polygon the computed color of the vertex listed in the following table. This is the last vertex to specify the polygon in all cases except single polygons, where the first vertex specifies the flat-shaded color.

Primitive Type of Polygon i: Vertex
Single polygon (i==1): 1
Triangle strip: i+2
Triangle fan: i+2
Independent triangle: 3â¢i
Quad strip: 2â¢i+2
Independent quad: 4â¢i

Flat and smooth shading are specified by glShadeModel with mode set to GL_FLAT and GL_SMOOTH, respectively.

GL_INVALID_ENUM is generated if mode is any value other than GL_FLAT or GL_SMOOTH.

GL_INVALID_OPERATION is generated if glShadeModel is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glShaderSource shader count string length

Replaces the source code in a shader object.

shader: Specifies the handle of the shader object whose source code is to be replaced.
count: Specifies the number of elements in the string and length arrays.
string: Specifies an array of pointers to strings containing the source code to be loaded into the shader.
length: Specifies an array of string lengths.

glShaderSource sets the source code in shader to the source code in the array of strings specified by string. Any source code previously stored in the shader object is completely replaced. The number of strings in the array is specified by count. If length is NULL, each string is assumed to be null terminated. If length is a value other than NULL, it points to an array containing a string length for each of the corresponding elements of string. Each element in the length array may contain the length of the corresponding string (the null character is not counted as part of the string length) or a value less than 0 to indicate that the string is null terminated. The source code strings are not scanned or parsed at this time; they are simply copied into the specified shader object.

GL_INVALID_VALUE is generated if shader is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if shader is not a shader object.

GL_INVALID_VALUE is generated if count is less than 0.

GL_INVALID_OPERATION is generated if glShaderSource is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glStencilFuncSeparate face func ref mask

Set front and/or back function and reference value for stencil testing.

face: Specifies whether front and/or back stencil state is updated. Three symbolic constants are valid: GL_FRONT, GL_BACK, and GL_FRONT_AND_BACK.
func: Specifies the test function. Eight symbolic constants are valid: GL_NEVER, GL_LESS, GL_LEQUAL, GL_GREATER, GL_GEQUAL, GL_EQUAL, GL_NOTEQUAL, and GL_ALWAYS. The initial value is GL_ALWAYS.
ref: Specifies the reference value for the stencil test. ref is clamped to the range [0,2^n-1], where n is the number of bitplanes in the stencil buffer. The initial value is 0.
mask: Specifies a mask that is ANDed with both the reference value and the stored stencil value when the test is done. The initial value is all 1’s.

Stenciling, like depth-buffering, enables and disables drawing on a per-pixel basis. You draw into the stencil planes using GL drawing primitives, then render geometry and images, using the stencil planes to mask out portions of the screen. Stenciling is typically used in multipass rendering algorithms to achieve special effects, such as decals, outlining, and constructive solid geometry rendering.

The stencil test conditionally eliminates a pixel based on the outcome of a comparison between the reference value and the value in the stencil buffer. To enable and disable the test, call glEnable and glDisable with argument GL_STENCIL_TEST. To specify actions based on the outcome of the stencil test, call glStencilOp or glStencilOpSeparate.

There can be two separate sets of func, ref, and mask parameters; one affects back-facing polygons, and the other affects front-facing polygons as well as other non-polygon primitives. glStencilFunc sets both front and back stencil state to the same values, as if glStencilFuncSeparate were called with face set to GL_FRONT_AND_BACK.

func is a symbolic constant that determines the stencil comparison function. It accepts one of eight values, shown in the following list. ref is an integer reference value that is used in the stencil comparison. It is clamped to the range [0,2^n-1], where n is the number of bitplanes in the stencil buffer. mask is bitwise ANDed with both the reference value and the stored stencil value, with the ANDed values participating in the comparison.

If stencil represents the value stored in the corresponding stencil buffer location, the following list shows the effect of each comparison function that can be specified by func. Only if the comparison succeeds is the pixel passed through to the next stage in the rasterization process (see glStencilOp). All tests treat stencil values as unsigned integers in the range [0,2^n-1], where n is the number of bitplanes in the stencil buffer.

The following values are accepted by func:

GL_NEVER: Always fails.
GL_LESS: Passes if ( ref & mask ) < ( stencil & mask ).
GL_LEQUAL: Passes if ( ref & mask ) <= ( stencil & mask ).
GL_GREATER: Passes if ( ref & mask ) > ( stencil & mask ).
GL_GEQUAL: Passes if ( ref & mask ) >= ( stencil & mask ).
GL_EQUAL: Passes if ( ref & mask ) = ( stencil & mask ).
GL_NOTEQUAL: Passes if ( ref & mask ) != ( stencil & mask ).
GL_ALWAYS: Always passes.

GL_INVALID_ENUM is generated if func is not one of the eight accepted values.

GL_INVALID_OPERATION is generated if glStencilFuncSeparate is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glStencilFunc func ref mask

Set front and back function and reference value for stencil testing.

func: Specifies the test function. Eight symbolic constants are valid: GL_NEVER, GL_LESS, GL_LEQUAL, GL_GREATER, GL_GEQUAL, GL_EQUAL, GL_NOTEQUAL, and GL_ALWAYS. The initial value is GL_ALWAYS.
ref: Specifies the reference value for the stencil test. ref is clamped to the range [0,2^n-1], where n is the number of bitplanes in the stencil buffer. The initial value is 0.
mask: Specifies a mask that is ANDed with both the reference value and the stored stencil value when the test is done. The initial value is all 1’s.

Stenciling, like depth-buffering, enables and disables drawing on a per-pixel basis. Stencil planes are first drawn into using GL drawing primitives, then geometry and images are rendered using the stencil planes to mask out portions of the screen. Stenciling is typically used in multipass rendering algorithms to achieve special effects, such as decals, outlining, and constructive solid geometry rendering.

There can be two separate sets of func, ref, and mask parameters; one affects back-facing polygons, and the other affects front-facing polygons as well as other non-polygon primitives. glStencilFunc sets both front and back stencil state to the same values. Use glStencilFuncSeparate to set front and back stencil state to different values.

The following values are accepted by func:

GL_NEVER: Always fails.
GL_LESS: Passes if ( ref & mask ) < ( stencil & mask ).
GL_LEQUAL: Passes if ( ref & mask ) <= ( stencil & mask ).
GL_GREATER: Passes if ( ref & mask ) > ( stencil & mask ).
GL_GEQUAL: Passes if ( ref & mask ) >= ( stencil & mask ).
GL_EQUAL: Passes if ( ref & mask ) = ( stencil & mask ).
GL_NOTEQUAL: Passes if ( ref & mask ) != ( stencil & mask ).
GL_ALWAYS: Always passes.

GL_INVALID_ENUM is generated if func is not one of the eight accepted values.

GL_INVALID_OPERATION is generated if glStencilFunc is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glStencilMaskSeparate face mask

Control the front and/or back writing of individual bits in the stencil planes.

face: Specifies whether the front and/or back stencil writemask is updated. Three symbolic constants are valid: GL_FRONT, GL_BACK, and GL_FRONT_AND_BACK.
mask: Specifies a bit mask to enable and disable writing of individual bits in the stencil planes. Initially, the mask is all 1’s.

glStencilMaskSeparate controls the writing of individual bits in the stencil planes. The least significant n bits of mask, where n is the number of bits in the stencil buffer, specify a mask. Where a 1 appears in the mask, it’s possible to write to the corresponding bit in the stencil buffer. Where a 0 appears, the corresponding bit is write-protected. Initially, all bits are enabled for writing.

There can be two separate mask writemasks; one affects back-facing polygons, and the other affects front-facing polygons as well as other non-polygon primitives. glStencilMask sets both front and back stencil writemasks to the same values, as if glStencilMaskSeparate were called with face set to GL_FRONT_AND_BACK.

GL_INVALID_OPERATION is generated if glStencilMaskSeparate is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glStencilMask mask

Control the front and back writing of individual bits in the stencil planes.

mask: Specifies a bit mask to enable and disable writing of individual bits in the stencil planes. Initially, the mask is all 1’s.

glStencilMask controls the writing of individual bits in the stencil planes. The least significant n bits of mask, where n is the number of bits in the stencil buffer, specify a mask. Where a 1 appears in the mask, it’s possible to write to the corresponding bit in the stencil buffer. Where a 0 appears, the corresponding bit is write-protected. Initially, all bits are enabled for writing.

There can be two separate mask writemasks; one affects back-facing polygons, and the other affects front-facing polygons as well as other non-polygon primitives. glStencilMask sets both front and back stencil writemasks to the same values. Use glStencilMaskSeparate to set front and back stencil writemasks to different values.

GL_INVALID_OPERATION is generated if glStencilMask is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glStencilOpSeparate face sfail dpfail dppass

Set front and/or back stencil test actions.

face: Specifies whether front and/or back stencil state is updated. Three symbolic constants are valid: GL_FRONT, GL_BACK, and GL_FRONT_AND_BACK.
sfail: Specifies the action to take when the stencil test fails. Eight symbolic constants are accepted: GL_KEEP, GL_ZERO, GL_REPLACE, GL_INCR, GL_INCR_WRAP, GL_DECR, GL_DECR_WRAP, and GL_INVERT. The initial value is GL_KEEP.
dpfail: Specifies the stencil action when the stencil test passes, but the depth test fails. dpfail accepts the same symbolic constants as sfail. The initial value is GL_KEEP.
dppass: Specifies the stencil action when both the stencil test and the depth test pass, or when the stencil test passes and either there is no depth buffer or depth testing is not enabled. dppass accepts the same symbolic constants as sfail. The initial value is GL_KEEP.

The stencil test conditionally eliminates a pixel based on the outcome of a comparison between the value in the stencil buffer and a reference value. To enable and disable the test, call glEnable and glDisable with argument GL_STENCIL_TEST; to control it, call glStencilFunc or glStencilFuncSeparate.

There can be two separate sets of sfail, dpfail, and dppass parameters; one affects back-facing polygons, and the other affects front-facing polygons as well as other non-polygon primitives. glStencilOp sets both front and back stencil state to the same values, as if glStencilOpSeparate were called with face set to GL_FRONT_AND_BACK.

glStencilOpSeparate takes three arguments that indicate what happens to the stored stencil value while stenciling is enabled. If the stencil test fails, no change is made to the pixel’s color or depth buffers, and sfail specifies what happens to the stencil buffer contents. The following eight actions are possible.

GL_KEEP: Keeps the current value.
GL_ZERO: Sets the stencil buffer value to 0.
GL_REPLACE: Sets the stencil buffer value to ref, as specified by glStencilFunc.
GL_INCR: Increments the current stencil buffer value. Clamps to the maximum representable unsigned value.
GL_INCR_WRAP: Increments the current stencil buffer value. Wraps stencil buffer value to zero when incrementing the maximum representable unsigned value.
GL_DECR: Decrements the current stencil buffer value. Clamps to 0.
GL_DECR_WRAP: Decrements the current stencil buffer value. Wraps stencil buffer value to the maximum representable unsigned value when decrementing a stencil buffer value of zero.
GL_INVERT: Bitwise inverts the current stencil buffer value.

Stencil buffer values are treated as unsigned integers. When incremented and decremented, values are clamped to 0 and 2^n-1, where n is the value returned by querying GL_STENCIL_BITS.

The other two arguments to glStencilOpSeparate specify stencil buffer actions that depend on whether subsequent depth buffer tests succeed (dppass) or fail (dpfail) (see glDepthFunc). The actions are specified using the same eight symbolic constants as sfail. Note that dpfail is ignored when there is no depth buffer, or when the depth buffer is not enabled. In these cases, sfail and dppass specify stencil action when the stencil test fails and passes, respectively.

GL_INVALID_ENUM is generated if face is any value other than GL_FRONT, GL_BACK, or GL_FRONT_AND_BACK.

GL_INVALID_ENUM is generated if sfail, dpfail, or dppass is any value other than the eight defined constant values.

GL_INVALID_OPERATION is generated if glStencilOpSeparate is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glStencilOp sfail dpfail dppass

Set front and back stencil test actions.

sfail: Specifies the action to take when the stencil test fails. Eight symbolic constants are accepted: GL_KEEP, GL_ZERO, GL_REPLACE, GL_INCR, GL_INCR_WRAP, GL_DECR, GL_DECR_WRAP, and GL_INVERT. The initial value is GL_KEEP.
dpfail: Specifies the stencil action when the stencil test passes, but the depth test fails. dpfail accepts the same symbolic constants as sfail. The initial value is GL_KEEP.
dppass: Specifies the stencil action when both the stencil test and the depth test pass, or when the stencil test passes and either there is no depth buffer or depth testing is not enabled. dppass accepts the same symbolic constants as sfail. The initial value is GL_KEEP.

There can be two separate sets of sfail, dpfail, and dppass parameters; one affects back-facing polygons, and the other affects front-facing polygons as well as other non-polygon primitives. glStencilOp sets both front and back stencil state to the same values. Use glStencilOpSeparate to set front and back stencil state to different values.

glStencilOp takes three arguments that indicate what happens to the stored stencil value while stenciling is enabled. If the stencil test fails, no change is made to the pixel’s color or depth buffers, and sfail specifies what happens to the stencil buffer contents. The following eight actions are possible.

GL_KEEP: Keeps the current value.
GL_ZERO: Sets the stencil buffer value to 0.
GL_REPLACE: Sets the stencil buffer value to ref, as specified by glStencilFunc.
GL_INCR: Increments the current stencil buffer value. Clamps to the maximum representable unsigned value.
GL_INCR_WRAP: Increments the current stencil buffer value. Wraps stencil buffer value to zero when incrementing the maximum representable unsigned value.
GL_DECR: Decrements the current stencil buffer value. Clamps to 0.
GL_DECR_WRAP: Decrements the current stencil buffer value. Wraps stencil buffer value to the maximum representable unsigned value when decrementing a stencil buffer value of zero.
GL_INVERT: Bitwise inverts the current stencil buffer value.

Stencil buffer values are treated as unsigned integers. When incremented and decremented, values are clamped to 0 and 2^n-1, where n is the value returned by querying GL_STENCIL_BITS.

The other two arguments to glStencilOp specify stencil buffer actions that depend on whether subsequent depth buffer tests succeed (dppass) or fail (dpfail) (see glDepthFunc). The actions are specified using the same eight symbolic constants as sfail. Note that dpfail is ignored when there is no depth buffer, or when the depth buffer is not enabled. In these cases, sfail and dppass specify stencil action when the stencil test fails and passes, respectively.

GL_INVALID_ENUM is generated if sfail, dpfail, or dppass is any value other than the eight defined constant values.

GL_INVALID_OPERATION is generated if glStencilOp is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTexCoordPointer size type stride pointer

Define an array of texture coordinates.

size: Specifies the number of coordinates per array element. Must be 1, 2, 3, or 4. The initial value is 4.
type: Specifies the data type of each texture coordinate. Symbolic constants GL_SHORT, GL_INT, GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
stride: Specifies the byte offset between consecutive texture coordinate sets. If stride is 0, the array elements are understood to be tightly packed. The initial value is 0.
pointer: Specifies a pointer to the first coordinate of the first texture coordinate set in the array. The initial value is 0.

glTexCoordPointer specifies the location and data format of an array of texture coordinates to use when rendering. size specifies the number of coordinates per texture coordinate set, and must be 1, 2, 3, or 4. type specifies the data type of each texture coordinate, and stride specifies the byte stride from one texture coordinate set to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on some implementations; see glInterleavedArrays.)

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer) while a texture coordinate array is specified, pointer is treated as a byte offset into the buffer object’s data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as texture coordinate vertex array client-side state (GL_TEXTURE_COORD_ARRAY_BUFFER_BINDING).

When a texture coordinate array is specified, size, type, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable a texture coordinate array, call glEnableClientState and glDisableClientState with the argument GL_TEXTURE_COORD_ARRAY. If enabled, the texture coordinate array is used when glArrayElement, glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, or glDrawRangeElements is called.

GL_INVALID_VALUE is generated if size is not 1, 2, 3, or 4.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if stride is negative.

Function: void glTexCoord1s s

Function: void glTexCoord1i s

Function: void glTexCoord1f s

Function: void glTexCoord1d s

Function: void glTexCoord2s s t

Function: void glTexCoord2i s t

Function: void glTexCoord2f s t

Function: void glTexCoord2d s t

Function: void glTexCoord3s s t r

Function: void glTexCoord3i s t r

Function: void glTexCoord3f s t r

Function: void glTexCoord3d s t r

Function: void glTexCoord4s s t r q

Function: void glTexCoord4i s t r q

Function: void glTexCoord4f s t r q

Function: void glTexCoord4d s t r q

Function: void glTexCoord1sv v

Function: void glTexCoord1iv v

Function: void glTexCoord1fv v

Function: void glTexCoord1dv v

Function: void glTexCoord2sv v

Function: void glTexCoord2iv v

Function: void glTexCoord2fv v

Function: void glTexCoord2dv v

Function: void glTexCoord3sv v

Function: void glTexCoord3iv v

Function: void glTexCoord3fv v

Function: void glTexCoord3dv v

Function: void glTexCoord4sv v

Function: void glTexCoord4iv v

Function: void glTexCoord4fv v

Function: void glTexCoord4dv v

Set the current texture coordinates.

s
t
r
q: Specify s, t, r, and q texture coordinates. Not all parameters are present in all forms of the command.

glTexCoord specifies texture coordinates in one, two, three, or four dimensions. glTexCoord1 sets the current texture coordinates to (s,001); a call to glTexCoord2 sets them to (s,t01). Similarly, glTexCoord3 specifies the texture coordinates as (s,tr1), and glTexCoord4 defines all four components explicitly as (s,trq).

The current texture coordinates are part of the data that is associated with each vertex and with the current raster position. Initially, the values for s, t, r, and q are (0, 0, 0, 1).

Function: void glTexEnvf target pname param

Function: void glTexEnvi target pname param

Function: void glTexEnvfv target pname params

Function: void glTexEnviv target pname params

Set texture environment parameters.

target: Specifies a texture environment. May be GL_TEXTURE_ENV, GL_TEXTURE_FILTER_CONTROL or GL_POINT_SPRITE.
pname: Specifies the symbolic name of a single-valued texture environment parameter. May be either GL_TEXTURE_ENV_MODE, GL_TEXTURE_LOD_BIAS, GL_COMBINE_RGB, GL_COMBINE_ALPHA, GL_SRC0_RGB, GL_SRC1_RGB, GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, GL_SRC2_ALPHA, GL_OPERAND0_RGB, GL_OPERAND1_RGB, GL_OPERAND2_RGB, GL_OPERAND0_ALPHA, GL_OPERAND1_ALPHA, GL_OPERAND2_ALPHA, GL_RGB_SCALE, GL_ALPHA_SCALE, or GL_COORD_REPLACE.
param: Specifies a single symbolic constant, one of GL_ADD, GL_ADD_SIGNED, GL_INTERPOLATE, GL_MODULATE, GL_DECAL, GL_BLEND, GL_REPLACE, GL_SUBTRACT, GL_COMBINE, GL_TEXTURE, GL_CONSTANT, GL_PRIMARY_COLOR, GL_PREVIOUS, GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, a single boolean value for the point sprite texture coordinate replacement, a single floating-point value for the texture level-of-detail bias, or 1.0, 2.0, or 4.0 when specifying the GL_RGB_SCALE or GL_ALPHA_SCALE.

A texture environment specifies how texture values are interpreted when a fragment is textured. When target is GL_TEXTURE_FILTER_CONTROL, pname must be GL_TEXTURE_LOD_BIAS. When target is GL_TEXTURE_ENV, pname can be GL_TEXTURE_ENV_MODE, GL_TEXTURE_ENV_COLOR, GL_COMBINE_RGB, GL_COMBINE_ALPHA, GL_RGB_SCALE, GL_ALPHA_SCALE, GL_SRC0_RGB, GL_SRC1_RGB, GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, or GL_SRC2_ALPHA.

If pname is GL_TEXTURE_ENV_MODE, then params is (or points to) the symbolic name of a texture function. Six texture functions may be specified: GL_ADD, GL_MODULATE, GL_DECAL, GL_BLEND, GL_REPLACE, or GL_COMBINE.

The following table shows the correspondence of filtered texture values R_t, G_t, B_t, A_t, L_t, I_t to texture source components. C_s and A_s are used by the texture functions described below.

Texture Base Internal Format: C_s, A_s
GL_ALPHA: (0, 0, 0) , A_t
GL_LUMINANCE: ( L_t, L_t, L_t ) , 1
GL_LUMINANCE_ALPHA: ( L_t, L_t, L_t ) , A_t
GL_INTENSITY: ( I_t, I_t, I_t ) , I_t
GL_RGB: ( R_t, G_t, B_t ) , 1
GL_RGBA: ( R_t, G_t, B_t ) , A_t

A texture function acts on the fragment to be textured using the texture image value that applies to the fragment (see glTexParameter) and produces an RGBA color for that fragment. The following table shows how the RGBA color is produced for each of the first five texture functions that can be chosen. C is a triple of color values (RGB) and A is the associated alpha value. RGBA values extracted from a texture image are in the range [0,1]. The subscript p refers to the color computed from the previous texture stage (or the incoming fragment if processing texture stage 0), the subscript s to the texture source color, the subscript c to the texture environment color, and the subscript v indicates a value produced by the texture function.

Texture Base Internal Format: Value, GL_REPLACE Function , GL_MODULATE Function , GL_DECAL Function , GL_BLEND Function , GL_ADD Function
GL_ALPHA: C_v=, C_p, C_p, undefined , C_p, C_p
.: A_v=, A_s, A_pâ¢A_s, , A_v=A_pâ¢A_s, A_pâ¢A_s
GL_LUMINANCE: C_v=, C_s, C_pâ¢C_s, undefined , C_pâ¢(1-C_s,)+C_câ¢C_s, C_p+C_s
(or 1): A_v=, A_p, A_p, , A_p, A_p
GL_LUMINANCE_ALPHA: C_v=, C_s, C_pâ¢C_s, undefined , C_pâ¢(1-C_s,)+C_câ¢C_s, C_p+C_s
(or 2): A_v=, A_s, A_pâ¢A_s, , A_pâ¢A_s, A_pâ¢A_s
GL_INTENSITY: C_v=, C_s, C_pâ¢C_s, undefined , C_pâ¢(1-C_s,)+C_câ¢C_s, C_p+C_s
.: A_v=, A_s, A_pâ¢A_s, , A_pâ¢(1-A_s,)+A_câ¢A_s, A_p+A_s
GL_RGB: C_v=, C_s, C_pâ¢C_s, C_s, C_pâ¢(1-C_s,)+C_câ¢C_s, C_p+C_s
(or 3): A_v=, A_p, A_p, A_p, A_p, A_p
GL_RGBA: C_v=, C_s, C_pâ¢C_s, C_pâ¢(1-A_s,)+C_sâ¢A_s, C_pâ¢(1-C_s,)+C_câ¢C_s, C_p+C_s
(or 4): A_v=, A_s, A_pâ¢A_s, A_p, A_pâ¢A_s, A_pâ¢A_s

If pname is GL_TEXTURE_ENV_MODE, and params is GL_COMBINE, the form of the texture function depends on the values of GL_COMBINE_RGB and GL_COMBINE_ALPHA.

The following describes how the texture sources, as specified by GL_SRC0_RGB, GL_SRC1_RGB, GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, and GL_SRC2_ALPHA, are combined to produce a final texture color. In the following tables, GL_SRC0_c is represented by Arg0, GL_SRC1_c is represented by Arg1, and GL_SRC2_c is represented by Arg2.

GL_COMBINE_RGB accepts any of GL_REPLACE, GL_MODULATE, GL_ADD, GL_ADD_SIGNED, GL_INTERPOLATE, GL_SUBTRACT, GL_DOT3_RGB, or GL_DOT3_RGBA.

GL_COMBINE_RGB: Texture Function
GL_REPLACE: Arg0
GL_MODULATE: Arg0ÃArg1
GL_ADD: Arg0+Arg1
GL_ADD_SIGNED: Arg0+Arg1-0.5
GL_INTERPOLATE: Arg0ÃArg2+Arg1Ã(1-Arg2,)
GL_SUBTRACT: Arg0-Arg1
GL_DOT3_RGB or GL_DOT3_RGBA: 4Ã(((Arg0_r,-0.5,)Ã(Arg1_r,-0.5,),)+((Arg0_g,-0.5,)Ã(Arg1_g,-0.5,),)+((Arg0_b,-0.5,)Ã(Arg1_b,-0.5,),),)

The scalar results for GL_DOT3_RGB and GL_DOT3_RGBA are placed into each of the 3 (RGB) or 4 (RGBA) components on output.

Likewise, GL_COMBINE_ALPHA accepts any of GL_REPLACE, GL_MODULATE, GL_ADD, GL_ADD_SIGNED, GL_INTERPOLATE, or GL_SUBTRACT. The following table describes how alpha values are combined:

GL_COMBINE_ALPHA: Texture Function
GL_REPLACE: Arg0
GL_MODULATE: Arg0ÃArg1
GL_ADD: Arg0+Arg1
GL_ADD_SIGNED: Arg0+Arg1-0.5
GL_INTERPOLATE: Arg0ÃArg2+Arg1Ã(1-Arg2,)
GL_SUBTRACT: Arg0-Arg1

In the following tables, the value C_s represents the color sampled from the currently bound texture, C_c represents the constant texture-environment color, C_f represents the primary color of the incoming fragment, and C_p represents the color computed from the previous texture stage or C_f if processing texture stage 0. Likewise, A_s, A_c, A_f, and A_p represent the respective alpha values.

The following table describes the values assigned to Arg0, Arg1, and Arg2 based upon the RGB sources and operands:

GL_SRCn_RGB: GL_OPERANDn_RGB, Argument Value
GL_TEXTURE: GL_SRC_COLOR, C_s,
.: GL_ONE_MINUS_SRC_COLOR, 1-C_s,
.: GL_SRC_ALPHA, A_s,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_s,
GL_TEXTUREn: GL_SRC_COLOR, C_s,
.: GL_ONE_MINUS_SRC_COLOR, 1-C_s,
.: GL_SRC_ALPHA, A_s,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_s,
GL_CONSTANT: GL_SRC_COLOR, C_c,
.: GL_ONE_MINUS_SRC_COLOR, 1-C_c,
.: GL_SRC_ALPHA, A_c,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_c,
GL_PRIMARY_COLOR: GL_SRC_COLOR, C_f,
.: GL_ONE_MINUS_SRC_COLOR, 1-C_f,
.: GL_SRC_ALPHA, A_f,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_f,
GL_PREVIOUS: GL_SRC_COLOR, C_p,
.: GL_ONE_MINUS_SRC_COLOR, 1-C_p,
.: GL_SRC_ALPHA, A_p,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_p,

For GL_TEXTUREn sources, C_s and A_s represent the color and alpha, respectively, produced from texture stage n.

The follow table describes the values assigned to Arg0, Arg1, and Arg2 based upon the alpha sources and operands:

GL_SRCn_ALPHA: GL_OPERANDn_ALPHA, Argument Value
GL_TEXTURE: GL_SRC_ALPHA, A_s,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_s,
GL_TEXTUREn: GL_SRC_ALPHA, A_s,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_s,
GL_CONSTANT: GL_SRC_ALPHA, A_c,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_c,
GL_PRIMARY_COLOR: GL_SRC_ALPHA, A_f,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_f,
GL_PREVIOUS: GL_SRC_ALPHA, A_p,
.: GL_ONE_MINUS_SRC_ALPHA, 1-A_p,

The RGB and alpha results of the texture function are multipled by the values of GL_RGB_SCALE and GL_ALPHA_SCALE, respectively, and clamped to the range [0,1].

If pname is GL_TEXTURE_ENV_COLOR, params is a pointer to an array that holds an RGBA color consisting of four values. Integer color components are interpreted linearly such that the most positive integer maps to 1.0, and the most negative integer maps to -1.0. The values are clamped to the range [0,1] when they are specified. C_c takes these four values.

If pname is GL_TEXTURE_LOD_BIAS, the value specified is added to the texture level-of-detail parameter, that selects which mipmap, or mipmaps depending upon the selected GL_TEXTURE_MIN_FILTER, will be sampled.

GL_TEXTURE_ENV_MODE defaults to GL_MODULATE and GL_TEXTURE_ENV_COLOR defaults to (0, 0, 0, 0).

If target is GL_POINT_SPRITE and pname is GL_COORD_REPLACE, the boolean value specified is used to either enable or disable point sprite texture coordinate replacement. The default value is GL_FALSE.

GL_INVALID_ENUM is generated when target or pname is not one of the accepted defined values, or when params should have a defined constant value (based on the value of pname) and does not.

GL_INVALID_VALUE is generated if the params value for GL_RGB_SCALE or GL_ALPHA_SCALE are not one of 1.0, 2.0, or 4.0.

GL_INVALID_OPERATION is generated if glTexEnv is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTexGeni coord pname param

Function: void glTexGenf coord pname param

Function: void glTexGend coord pname param

Function: void glTexGeniv coord pname params

Function: void glTexGenfv coord pname params

Function: void glTexGendv coord pname params

Control the generation of texture coordinates.

coord: Specifies a texture coordinate. Must be one of GL_S, GL_T, GL_R, or GL_Q.
pname: Specifies the symbolic name of the texture-coordinate generation function. Must be GL_TEXTURE_GEN_MODE.
param: Specifies a single-valued texture generation parameter, one of GL_OBJECT_LINEAR, GL_EYE_LINEAR, GL_SPHERE_MAP, GL_NORMAL_MAP, or GL_REFLECTION_MAP.

glTexGen selects a texture-coordinate generation function or supplies coefficients for one of the functions. coord names one of the (s, t, r, q) texture coordinates; it must be one of the symbols GL_S, GL_T, GL_R, or GL_Q. pname must be one of three symbolic constants: GL_TEXTURE_GEN_MODE, GL_OBJECT_PLANE, or GL_EYE_PLANE. If pname is GL_TEXTURE_GEN_MODE, then params chooses a mode, one of GL_OBJECT_LINEAR, GL_EYE_LINEAR, GL_SPHERE_MAP, GL_NORMAL_MAP, or GL_REFLECTION_MAP. If pname is either GL_OBJECT_PLANE or GL_EYE_PLANE, params contains coefficients for the corresponding texture generation function.

If the texture generation function is GL_OBJECT_LINEAR, the function

g=p_1Ãx_o+p_2Ãy_o+p_3Ãz_o+p_4Ãw_o

is used, where g is the value computed for the coordinate named in coord, p_1, p_2, p_3, and p_4 are the four values supplied in params, and x_o, y_o, z_o, and w_o are the object coordinates of the vertex. This function can be used, for example, to texture-map terrain using sea level as a reference plane (defined by p_1, p_2, p_3, and p_4). The altitude of a terrain vertex is computed by the GL_OBJECT_LINEAR coordinate generation function as its distance from sea level; that altitude can then be used to index the texture image to map white snow onto peaks and green grass onto foothills.

If the texture generation function is GL_EYE_LINEAR, the function

g=p_1,^â³Ãx_e+p_2,^â³Ãy_e+p_3,^â³Ãz_e+p_4,^â³Ãw_e

is used, where

(p_1,^â³â¢p_2,^â³â¢p_3,^â³â¢p_4,^â³,)=(p_1â¢p_2â¢p_3â¢p_4,)â¢M^-1

and x_e, y_e, z_e, and w_e are the eye coordinates of the vertex, p_1, p_2, p_3, and p_4 are the values supplied in params, and M is the modelview matrix when glTexGen is invoked. If M is poorly conditioned or singular, texture coordinates generated by the resulting function may be inaccurate or undefined.

Note that the values in params define a reference plane in eye coordinates. The modelview matrix that is applied to them may not be the same one in effect when the polygon vertices are transformed. This function establishes a field of texture coordinates that can produce dynamic contour lines on moving objects.

If the texture generation function is GL_SPHERE_MAP and coord is either GL_S or GL_T, s and t texture coordinates are generated as follows. Let u be the unit vector pointing from the origin to the polygon vertex (in eye coordinates). Let n sup prime be the current normal, after transformation to eye coordinates. Let

f=(f_xâ¢f_yâ¢f_z,)^T be the reflection vector such that

f=u-2â¢n^â³â¢n^â³,^Tâ¢u

Finally, let m=2â¢â(f_x,^2+f_y,^2+(f_z+1,)^2,). Then the values assigned to the s and t texture coordinates are

s=f_x/m+1/2

t=f_y/m+1/2

To enable or disable a texture-coordinate generation function, call glEnable or glDisable with one of the symbolic texture-coordinate names (GL_TEXTURE_GEN_S, GL_TEXTURE_GEN_T, GL_TEXTURE_GEN_R, or GL_TEXTURE_GEN_Q) as the argument. When enabled, the specified texture coordinate is computed according to the generating function associated with that coordinate. When disabled, subsequent vertices take the specified texture coordinate from the current set of texture coordinates. Initially, all texture generation functions are set to GL_EYE_LINEAR and are disabled. Both s plane equations are (1, 0, 0, 0), both t plane equations are (0, 1, 0, 0), and all r and q plane equations are (0, 0, 0, 0).

When the ARB_multitexture extension is supported, glTexGen sets the texture generation parameters for the currently active texture unit, selected with glActiveTexture.

GL_INVALID_ENUM is generated when coord or pname is not an accepted defined value, or when pname is GL_TEXTURE_GEN_MODE and params is not an accepted defined value.

GL_INVALID_ENUM is generated when pname is GL_TEXTURE_GEN_MODE, params is GL_SPHERE_MAP, and coord is either GL_R or GL_Q.

GL_INVALID_OPERATION is generated if glTexGen is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTexImage1D target level internalFormat width border format type data

Specify a one-dimensional texture image.

target: Specifies the target texture. Must be GL_TEXTURE_1D or GL_PROXY_TEXTURE_1D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
internalFormat: Specifies the number of color components in the texture. Must be 1, 2, 3, or 4, or one of the following symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_COMPRESSED_ALPHA, GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_INTENSITY, GL_COMPRESSED_RGB, GL_COMPRESSED_RGBA, GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, GL_DEPTH_COMPONENT32, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, GL_RGBA16, GL_SLUMINANCE, GL_SLUMINANCE8, GL_SLUMINANCE_ALPHA, GL_SLUMINANCE8_ALPHA8, GL_SRGB, GL_SRGB8, GL_SRGB_ALPHA, or GL_SRGB8_ALPHA8.
width: Specifies the width of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^n+2â¡(border,) for some integer n. All implementations support texture images that are at least 64 texels wide. The height of the 1D texture image is 1.
border: Specifies the width of the border. Must be either 0 or 1.
format: Specifies the format of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
data: Specifies a pointer to the image data in memory.

Texture images are defined with glTexImage1D. The arguments describe the parameters of the texture image, such as width, width of the border, level-of-detail number (see glTexParameter), and the internal resolution and format used to store the image. The last three arguments describe how the image is represented in memory; they are identical to the pixel formats used for glDrawPixels.

If target is GL_TEXTURE_1D, data is read from data as a sequence of signed or unsigned bytes, shorts, or longs, or single-precision floating-point values, depending on type. These values are grouped into sets of one, two, three, or four values, depending on format, to form elements. If type is GL_BITMAP, the data is considered as a string of unsigned bytes (and format must be GL_COLOR_INDEX). Each data byte is treated as eight 1-bit elements, with bit ordering determined by GL_UNPACK_LSB_FIRST (see glPixelStore).

The first element corresponds to the left end of the texture array. Subsequent elements progress left-to-right through the remaining texels in the texture array. The final element corresponds to the right end of the texture array.

format determines the composition of each element in data. It can assume one of these symbolic values:

GL_COLOR_INDEX: Each element is a single value, a color index. The GL converts it to fixed point (with an unspecified number of zero bits to the right of the binary point), shifted left or right depending on the value and sign of GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET (see glPixelTransfer). The resulting index is converted to a set of color components using the GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].
GL_RED: Each element is a single red component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for green and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_GREEN: Each element is a single green component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_BLUE: Each element is a single blue component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and green, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_ALPHA: Each element is a single alpha component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_INTENSITY: Each element is a single intensity value. The GL converts it to floating point, then assembles it into an RGBA element by replicating the intensity value three times for red, green, blue, and alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_RGB
GL_BGR: Each element is an RGB triple. The GL converts it to floating point and assembles it into an RGBA element by attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_RGBA
GL_BGRA: Each element contains all four components. Each component is multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_LUMINANCE: Each element is a single luminance value. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue and attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_LUMINANCE_ALPHA: Each element is a luminance/alpha pair. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_DEPTH_COMPONENT: Each element is a single depth value. The GL converts it to floating point, multiplies by the signed scale factor GL_DEPTH_SCALE, adds the signed bias GL_DEPTH_BIAS, and clamps to the range [0,1] (see glPixelTransfer).

Refer to the glDrawPixels reference page for a description of the acceptable values for the type parameter.

If an application wants to store the texture at a certain resolution or in a certain format, it can request the resolution and format with internalFormat. The GL will choose an internal representation that closely approximates that requested by internalFormat, but it may not match exactly. (The representations specified by GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, and GL_RGBA must match exactly. The numeric values 1, 2, 3, and 4 may also be used to specify the above representations.)

If the internalFormat parameter is one of the generic compressed formats, GL_COMPRESSED_ALPHA, GL_COMPRESSED_INTENSITY, GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_RGB, or GL_COMPRESSED_RGBA, the GL will replace the internal format with the symbolic constant for a specific internal format and compress the texture before storage. If no corresponding internal format is available, or the GL can not compress that image for any reason, the internal format is instead replaced with a corresponding base internal format.

If the internalFormat parameter is GL_SRGB, GL_SRGB8, GL_SRGB_ALPHA, GL_SRGB8_ALPHA8, GL_SLUMINANCE, GL_SLUMINANCE8, GL_SLUMINANCE_ALPHA, or GL_SLUMINANCE8_ALPHA8, the texture is treated as if the red, green, blue, or luminance components are encoded in the sRGB color space. Any alpha component is left unchanged. The conversion from the sRGB encoded component c_s to a linear component c_l is:

c_l={(c_s/12.92 if c_sâ¤0.04045), ((c_s+0.055/1.055)^2.4 if c_s>0.04045)

Assume c_s is the sRGB component in the range [0,1].

Use the GL_PROXY_TEXTURE_1D target to try out a resolution and format. The implementation will update and recompute its best match for the requested storage resolution and format. To then query this state, call glGetTexLevelParameter. If the texture cannot be accommodated, texture state is set to 0.

A one-component texture image uses only the red component of the RGBA color from data. A two-component image uses the R and A values. A three-component image uses the R, G, and B values. A four-component image uses all of the RGBA components.

Depth textures can be treated as LUMINANCE, INTENSITY or ALPHA textures during texture filtering and application. Â Image-based shadowingÂ canÂ be Â enabledÂ byÂ comparing texture r coordinates to depth texture values to generate a boolean result. See glTexParameter for details on texture comparison.

GL_INVALID_ENUM is generated if target is not GL_TEXTURE_1D or GL_PROXY_TEXTURE_1D.

GL_INVALID_ENUM is generated if format is not an accepted format constant. Format constants other than GL_STENCIL_INDEX are accepted.

GL_INVALID_ENUM is generated if type is not a type constant.

GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2â¡(max,), where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if internalFormat is not 1, 2, 3, 4, or one of the accepted resolution and format symbolic constants.

GL_INVALID_VALUE is generated if width is less than 0 or greater than 2 + GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if non-power-of-two textures are not supported and the width cannot be represented as 2^n+2â¡(border,) for some integer value of n.

GL_INVALID_VALUE is generated if border is not 0 or 1.

GL_INVALID_OPERATION is generated if format is GL_DEPTH_COMPONENT and internalFormat is not GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT32.

GL_INVALID_OPERATION is generated if internalFormat is GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT32, and format is not GL_DEPTH_COMPONENT.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glTexImage1D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTexImage2D target level internalFormat width height border format type data

Specify a two-dimensional texture image.

target: Specifies the target texture. Must be GL_TEXTURE_2D, GL_PROXY_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, or GL_PROXY_TEXTURE_CUBE_MAP.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
internalFormat: Specifies the number of color components in the texture. Must be 1, 2, 3, or 4, or one of the following symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_COMPRESSED_ALPHA, GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_INTENSITY, GL_COMPRESSED_RGB, GL_COMPRESSED_RGBA, GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, GL_DEPTH_COMPONENT32, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, GL_RGBA16, GL_SLUMINANCE, GL_SLUMINANCE8, GL_SLUMINANCE_ALPHA, GL_SLUMINANCE8_ALPHA8, GL_SRGB, GL_SRGB8, GL_SRGB_ALPHA, or GL_SRGB8_ALPHA8.
width: Specifies the width of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^n+2â¡(border,) for some integer n. All implementations support texture images that are at least 64 texels wide.
height: Specifies the height of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^m+2â¡(border,) for some integer m. All implementations support texture images that are at least 64 texels high.
border: Specifies the width of the border. Must be either 0 or 1.
format: Specifies the format of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
data: Specifies a pointer to the image data in memory.

Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable two-dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_2D. To enable and disable texturing using cube-mapped texture, call glEnable and glDisable with argument GL_TEXTURE_CUBE_MAP.

To define texture images, call glTexImage2D. The arguments describe the parameters of the texture image, such as height, width, width of the border, level-of-detail number (see glTexParameter), and number of color components provided. The last three arguments describe how the image is represented in memory; they are identical to the pixel formats used for glDrawPixels.

If target is GL_PROXY_TEXTURE_2D or GL_PROXY_TEXTURE_CUBE_MAP, no data is read from data, but all of the texture image state is recalculated, checked for consistency, and checked against the implementation’s capabilities. If the implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but does not generate an error (see glGetError). To query for an entire mipmap array, use an image array level greater than or equal to 1.

If target is GL_TEXTURE_2D, or one of the GL_TEXTURE_CUBE_MAP targets, data is read from data as a sequence of signed or unsigned bytes, shorts, or longs, or single-precision floating-point values, depending on type. These values are grouped into sets of one, two, three, or four values, depending on format, to form elements. If type is GL_BITMAP, the data is considered as a string of unsigned bytes (and format must be GL_COLOR_INDEX). Each data byte is treated as eight 1-bit elements, with bit ordering determined by GL_UNPACK_LSB_FIRST (see glPixelStore).

The first element corresponds to the lower left corner of the texture image. Subsequent elements progress left-to-right through the remaining texels in the lowest row of the texture image, and then in successively higher rows of the texture image. The final element corresponds to the upper right corner of the texture image.

format determines the composition of each element in data. It can assume one of these symbolic values:

GL_COLOR_INDEX: Each element is a single value, a color index. The GL converts it to fixed point (with an unspecified number of zero bits to the right of the binary point), shifted left or right depending on the value and sign of GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET (see glPixelTransfer). The resulting index is converted to a set of color components using the GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].
GL_RED: Each element is a single red component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for green and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_GREEN: Each element is a single green component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_BLUE: Each element is a single blue component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and green, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_ALPHA: Each element is a single alpha component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_INTENSITY: Each element is a single intensity value. The GL converts it to floating point, then assembles it into an RGBA element by replicating the intensity value three times for red, green, blue, and alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_RGB
GL_BGR: Each element is an RGB triple. The GL converts it to floating point and assembles it into an RGBA element by attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_RGBA
GL_BGRA: Each element contains all four components. Each component is multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_LUMINANCE: Each element is a single luminance value. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue and attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_LUMINANCE_ALPHA: Each element is a luminance/alpha pair. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_DEPTH_COMPONENT: Each element is a single depth value. The GL converts it to floating point, multiplies by the signed scale factor GL_DEPTH_SCALE, adds the signed bias GL_DEPTH_BIAS, and clamps to the range [0,1] (see glPixelTransfer).

Refer to the glDrawPixels reference page for a description of the acceptable values for the type parameter.

c_l={(c_s/12.92 if c_sâ¤0.04045), ((c_s+0.055/1.055)^2.4 if c_s>0.04045)

Assume c_s is the sRGB component in the range [0,1].

Use the GL_PROXY_TEXTURE_2D or GL_PROXY_TEXTURE_CUBE_MAP target to try out a resolution and format. The implementation will update and recompute its best match for the requested storage resolution and format. To then query this state, call glGetTexLevelParameter. If the texture cannot be accommodated, texture state is set to 0.

A one-component texture image uses only the red component of the RGBA color extracted from data. A two-component image uses the R and A values. A three-component image uses the R, G, and B values. A four-component image uses all of the RGBA components.

GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D, GL_PROXY_TEXTURE_2D, GL_PROXY_TEXTURE_CUBE_MAP, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.

GL_INVALID_ENUM is generated if target is one of the six cube map 2D image targets and the width and height parameters are not equal.

GL_INVALID_ENUM is generated if type is not a type constant.

GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.

GL_INVALID_VALUE is generated if width or height is less than 0 or greater than 2 + GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2â¡(max,), where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if internalFormat is not 1, 2, 3, 4, or one of the accepted resolution and format symbolic constants.

GL_INVALID_VALUE is generated if width or height is less than 0 or greater than 2 + GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if non-power-of-two textures are not supported and the width or height cannot be represented as 2^k+2â¡(border,) for some integer value of k.

GL_INVALID_VALUE is generated if border is not 0 or 1.

GL_INVALID_OPERATION is generated if target is not GL_TEXTURE_2D or GL_PROXY_TEXTURE_2D and internalFormat is GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT32.

GL_INVALID_OPERATION is generated if format is GL_DEPTH_COMPONENT and internalFormat is not GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT32.

GL_INVALID_OPERATION is generated if internalFormat is GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT32, and format is not GL_DEPTH_COMPONENT.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glTexImage2D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTexImage3D target level internalFormat width height depth border format type data

Specify a three-dimensional texture image.

target: Specifies the target texture. Must be GL_TEXTURE_3D or GL_PROXY_TEXTURE_3D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the n^th mipmap reduction image.
internalFormat: Specifies the number of color components in the texture. Must be 1, 2, 3, or 4, or one of the following symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_COMPRESSED_ALPHA, GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_INTENSITY, GL_COMPRESSED_RGB, GL_COMPRESSED_RGBA, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, GL_RGBA16, GL_SLUMINANCE, GL_SLUMINANCE8, GL_SLUMINANCE_ALPHA, GL_SLUMINANCE8_ALPHA8, GL_SRGB, GL_SRGB8, GL_SRGB_ALPHA, or GL_SRGB8_ALPHA8.
width: Specifies the width of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^n+2â¡(border,) for some integer n. All implementations support 3D texture images that are at least 16 texels wide.
height: Specifies the height of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^m+2â¡(border,) for some integer m. All implementations support 3D texture images that are at least 16 texels high.
depth: Specifies the depth of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be 2^k+2â¡(border,) for some integer k. All implementations support 3D texture images that are at least 16 texels deep.
border: Specifies the width of the border. Must be either 0 or 1.
format: Specifies the format of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
data: Specifies a pointer to the image data in memory.

To define texture images, call glTexImage3D. The arguments describe the parameters of the texture image, such as height, width, depth, width of the border, level-of-detail number (see glTexParameter), and number of color components provided. The last three arguments describe how the image is represented in memory; they are identical to the pixel formats used for glDrawPixels.

If target is GL_TEXTURE_3D, data is read from data as a sequence of signed or unsigned bytes, shorts, or longs, or single-precision floating-point values, depending on type. These values are grouped into sets of one, two, three, or four values, depending on format, to form elements. If type is GL_BITMAP, the data is considered as a string of unsigned bytes (and format must be GL_COLOR_INDEX). Each data byte is treated as eight 1-bit elements, with bit ordering determined by GL_UNPACK_LSB_FIRST (see glPixelStore).

format determines the composition of each element in data. It can assume one of these symbolic values:

GL_COLOR_INDEX: Each element is a single value, a color index. The GL converts it to fixed point (with an unspecified number of zero bits to the right of the binary point), shifted left or right depending on the value and sign of GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET (see glPixelTransfer). The resulting index is converted to a set of color components using the GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].
GL_RED: Each element is a single red component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for green and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_GREEN: Each element is a single green component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_BLUE: Each element is a single blue component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and green, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_ALPHA: Each element is a single alpha component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_INTENSITY: Each element is a single intensity value. The GL converts it to floating point, then assembles it into an RGBA element by replicating the intensity value three times for red, green, blue, and alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_RGB
GL_BGR: Each element is an RGB triple. The GL converts it to floating point and assembles it into an RGBA element by attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_RGBA
GL_BGRA: Each element contains all four components. Each component is multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_LUMINANCE: Each element is a single luminance value. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue and attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).
GL_LUMINANCE_ALPHA: Each element is a luminance/alpha pair. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer).

Refer to the glDrawPixels reference page for a description of the acceptable values for the type parameter.

c_l={(c_s/12.92 if c_sâ¤0.04045), ((c_s+0.055/1.055)^2.4 if c_s>0.04045)

Assume c_s is the sRGB component in the range [0,1].

Use the GL_PROXY_TEXTURE_3D target to try out a resolution and format. The implementation will update and recompute its best match for the requested storage resolution and format. To then query this state, call glGetTexLevelParameter. If the texture cannot be accommodated, texture state is set to 0.

GL_INVALID_ENUM is generated if target is not GL_TEXTURE_3D or GL_PROXY_TEXTURE_3D.

GL_INVALID_ENUM is generated if format is not an accepted format constant. Format constants other than GL_STENCIL_INDEX and GL_DEPTH_COMPONENT are accepted.

GL_INVALID_ENUM is generated if type is not a type constant.

GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2â¡(max,), where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if internalFormat is not 1, 2, 3, 4, or one of the accepted resolution and format symbolic constants.

GL_INVALID_VALUE is generated if width, height, or depth is less than 0 or greater than 2 + GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if non-power-of-two textures are not supported and the width, height, or depth cannot be represented as 2^k+2â¡(border,) for some integer value of k.

GL_INVALID_VALUE is generated if border is not 0 or 1.

GL_INVALID_OPERATION is generated if format or internalFormat is GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT32.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glTexImage3D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTexParameterf target pname param

Function: void glTexParameteri target pname param

Function: void glTexParameterfv target pname params

Function: void glTexParameteriv target pname params

Set texture parameters.

target: Specifies the target texture, which must be either GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, or GL_TEXTURE_CUBE_MAP.
pname: Specifies the symbolic name of a single-valued texture parameter. pname can be one of the following: GL_TEXTURE_MIN_FILTER, GL_TEXTURE_MAG_FILTER, GL_TEXTURE_MIN_LOD, GL_TEXTURE_MAX_LOD, GL_TEXTURE_BASE_LEVEL, GL_TEXTURE_MAX_LEVEL, GL_TEXTURE_WRAP_S, GL_TEXTURE_WRAP_T, GL_TEXTURE_WRAP_R, GL_TEXTURE_PRIORITY, GL_TEXTURE_COMPARE_MODE, GL_TEXTURE_COMPARE_FUNC, GL_DEPTH_TEXTURE_MODE, or GL_GENERATE_MIPMAP.
param: Specifies the value of pname.

Texture mapping is a technique that applies an image onto an object’s surface as if the image were a decal or cellophane shrink-wrap. The image is created in texture space, with an (s, t) coordinate system. A texture is a one- or two-dimensional image and a set of parameters that determine how samples are derived from the image.

glTexParameter assigns the value or values in params to the texture parameter specified as pname. target defines the target texture, either GL_TEXTURE_1D, GL_TEXTURE_2D, or GL_TEXTURE_3D. The following symbols are accepted in pname:

GL_TEXTURE_MIN_FILTER

The texture minifying function is used whenever the pixel being textured maps to an area greater than one texture element. There are six defined minifying functions. Two of them use the nearest one or nearest four texture elements to compute the texture value. The other four use mipmaps.

A mipmap is an ordered set of arrays representing the same image at progressively lower resolutions. If the texture has dimensions 2^nÃ2^m, there are maxâ¡(n,m)+1 mipmaps. The first mipmap is the original texture, with dimensions 2^nÃ2^m. Each subsequent mipmap has dimensions 2^k-1,Ã2^l-1,, where 2^kÃ2^l are the dimensions of the previous mipmap, until either k=0 or l=0. At that point, subsequent mipmaps have dimension 1Ã2^l-1, or 2^k-1,Ã1 until the final mipmap, which has dimension 1Ã1. To define the mipmaps, call glTexImage1D, glTexImage2D, glTexImage3D, glCopyTexImage1D, or glCopyTexImage2D with the level argument indicating the order of the mipmaps. Level 0 is the original texture; level maxâ¡(n,m) is the final 1Ã1 mipmap.

params supplies a function for minifying the texture as one of the following:

As more texture elements are sampled in the minification process, fewer aliasing artifacts will be apparent. While the GL_NEAREST and GL_LINEAR minification functions can be faster than the other four, they sample only one or four texture elements to determine the texture value of the pixel being rendered and can produce moire patterns or ragged transitions. The initial value of GL_TEXTURE_MIN_FILTER is GL_NEAREST_MIPMAP_LINEAR.

GL_TEXTURE_MAG_FILTER

The texture magnification function is used when the pixel being textured maps to an area less than or equal to one texture element. It sets the texture magnification function to either GL_NEAREST or GL_LINEAR (see below). GL_NEAREST is generally faster than GL_LINEAR, but it can produce textured images with sharper edges because the transition between texture elements is not as smooth. The initial value of GL_TEXTURE_MAG_FILTER is GL_LINEAR.

GL_NEAREST: Returns the value of the texture element that is nearest (in Manhattan distance) to the center of the pixel being textured.
GL_LINEAR: Returns the weighted average of the four texture elements that are closest to the center of the pixel being textured. These can include border texture elements, depending on the values of GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T, and on the exact mapping.
GL_NEAREST_MIPMAP_NEAREST: Chooses the mipmap that most closely matches the size of the pixel being textured and uses the GL_NEAREST criterion (the texture element nearest to the center of the pixel) to produce a texture value.
GL_LINEAR_MIPMAP_NEAREST: Chooses the mipmap that most closely matches the size of the pixel being textured and uses the GL_LINEAR criterion (a weighted average of the four texture elements that are closest to the center of the pixel) to produce a texture value.
GL_NEAREST_MIPMAP_LINEAR: Chooses the two mipmaps that most closely match the size of the pixel being textured and uses the GL_NEAREST criterion (the texture element nearest to the center of the pixel) to produce a texture value from each mipmap. The final texture value is a weighted average of those two values.
GL_LINEAR_MIPMAP_LINEAR: Chooses the two mipmaps that most closely match the size of the pixel being textured and uses the GL_LINEAR criterion (a weighted average of the four texture elements that are closest to the center of the pixel) to produce a texture value from each mipmap. The final texture value is a weighted average of those two values.

GL_NEAREST: Returns the value of the texture element that is nearest (in Manhattan distance) to the center of the pixel being textured.
GL_LINEAR: Returns the weighted average of the four texture elements that are closest to the center of the pixel being textured. These can include border texture elements, depending on the values of GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T, and on the exact mapping.

GL_TEXTURE_MIN_LOD: Sets the minimum level-of-detail parameter. This floating-point value limits the selection of highest resolution mipmap (lowest mipmap level). The initial value is -1000.

GL_TEXTURE_MAX_LOD: Sets the maximum level-of-detail parameter. This floating-point value limits the selection of the lowest resolution mipmap (highest mipmap level). The initial value is 1000.

GL_TEXTURE_BASE_LEVEL: Specifies the index of the lowest defined mipmap level. This is an integer value. The initial value is 0.

GL_TEXTURE_MAX_LEVEL: Sets the index of the highest defined mipmap level. This is an integer value. The initial value is 1000.

GL_TEXTURE_WRAP_S: Sets the wrap parameter for texture coordinate s to either GL_CLAMP, GL_CLAMP_TO_BORDER, GL_CLAMP_TO_EDGE, GL_MIRRORED_REPEAT, or GL_REPEAT. GL_CLAMP causes s coordinates to be clamped to the range [0,1] and is useful for preventing wrapping artifacts when mapping a single image onto an object. GL_CLAMP_TO_BORDER causes the s coordinate to be clamped to the range [-1/2N,,1+1/2N,], where N is the size of the texture in the direction of clamping.GL_CLAMP_TO_EDGE causes s coordinates to be clamped to the range [1/2N,,1-1/2N,], where N is the size of the texture in the direction of clamping. GL_REPEAT causes the integer part of the s coordinate to be ignored; the GL uses only the fractional part, thereby creating a repeating pattern. GL_MIRRORED_REPEAT causes the s coordinate to be set to the fractional part of the texture coordinate if the integer part of s is even; if the integer part of s is odd, then the s texture coordinate is set to 1-fracâ¡(s,), where fracâ¡(s,) represents the fractional part of s. Border texture elements are accessed only if wrapping is set to GL_CLAMP or GL_CLAMP_TO_BORDER. Initially, GL_TEXTURE_WRAP_S is set to GL_REPEAT.

GL_TEXTURE_WRAP_T: Sets the wrap parameter for texture coordinate t to either GL_CLAMP, GL_CLAMP_TO_BORDER, GL_CLAMP_TO_EDGE, GL_MIRRORED_REPEAT, or GL_REPEAT. See the discussion under GL_TEXTURE_WRAP_S. Initially, GL_TEXTURE_WRAP_T is set to GL_REPEAT.
GL_TEXTURE_WRAP_R: Sets the wrap parameter for texture coordinate r to either GL_CLAMP, GL_CLAMP_TO_BORDER, GL_CLAMP_TO_EDGE, GL_MIRRORED_REPEAT, or GL_REPEAT. See the discussion under GL_TEXTURE_WRAP_S. Initially, GL_TEXTURE_WRAP_R is set to GL_REPEAT.
GL_TEXTURE_BORDER_COLOR: Sets a border color. params contains four values that comprise the RGBA color of the texture border. Integer color components are interpreted linearly such that the most positive integer maps to 1.0, and the most negative integer maps to -1.0. The values are clamped to the range [0,1] when they are specified. Initially, the border color is (0, 0, 0, 0).
GL_TEXTURE_PRIORITY: Specifies the texture residence priority of the currently bound texture. Permissible values are in the range [0,1]. See glPrioritizeTextures and glBindTexture for more information.
GL_TEXTURE_COMPARE_MODE: Specifies the texture comparison mode for currently bound depth textures. That is, a texture whose internal format is GL_DEPTH_COMPONENT_*; see glTexImage2D) Permissible values are:
GL_TEXTURE_COMPARE_FUNC: Specifies the comparison operator used when GL_TEXTURE_COMPARE_MODE is set to GL_COMPARE_R_TO_TEXTURE. Permissible values are: where r is the current interpolated texture coordinate, and D_t is the depth texture value sampled from the currently bound depth texture. result is assigned to the either the luminance, intensity, or alpha (as specified by GL_DEPTH_TEXTURE_MODE.)
GL_DEPTH_TEXTURE_MODE: Specifies a single symbolic constant indicating how depth values should be treated during filtering and texture application. Accepted values are GL_LUMINANCE, GL_INTENSITY, and GL_ALPHA. The initial value is GL_LUMINANCE.
GL_GENERATE_MIPMAP: Specifies a boolean value that indicates if all levels of a mipmap array should be automatically updated when any modification to the base level mipmap is done. The initial value is GL_FALSE.

GL_COMPARE_R_TO_TEXTURE: Specifies that the interpolated and clamped r texture coordinate should be compared to the value in the currently bound depth texture. See the discussion of GL_TEXTURE_COMPARE_FUNC for details of how the comparison is evaluated. The result of the comparison is assigned to luminance, intensity, or alpha (as specified by GL_DEPTH_TEXTURE_MODE).
GL_NONE: Specifies that the luminance, intensity, or alpha (as specified by GL_DEPTH_TEXTURE_MODE) should be assigned the appropriate value from the currently bound depth texture.

Texture Comparison Function: Computed result
GL_LEQUAL: result={(1.0), (0.0)â¢Â (r<=D_t,), (r>D_t,),
GL_GEQUAL: result={(1.0), (0.0)â¢Â (r>=D_t,), (r<D_t,),
GL_LESS: result={(1.0), (0.0)â¢Â (r<D_t,), (r>=D_t,),
GL_GREATER: result={(1.0), (0.0)â¢Â (r>D_t,), (r<=D_t,),
GL_EQUAL: result={(1.0), (0.0)â¢Â (r=D_t,), (râ D_t,),
GL_NOTEQUAL: result={(1.0), (0.0)â¢Â (râ D_t,), (r=D_t,),
GL_ALWAYS: result=1.0
GL_NEVER: result=0.0

GL_INVALID_ENUM is generated if target or pname is not one of the accepted defined values.

GL_INVALID_ENUM is generated if params should have a defined constant value (based on the value of pname) and does not.

GL_INVALID_OPERATION is generated if glTexParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTexSubImage1D target level xoffset width format type data

Specify a one-dimensional texture subimage.

target: Specifies the target texture. Must be GL_TEXTURE_1D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset: Specifies a texel offset in the x direction within the texture array.
width: Specifies the width of the texture subimage.
format: Specifies the format of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
data: Specifies a pointer to the image data in memory.

Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable or disable one-dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_1D.

glTexSubImage1D redefines a contiguous subregion of an existing one-dimensional texture image. The texels referenced by data replace the portion of the existing texture array with x indices xoffset and xoffset+width-1, inclusive. This region may not include any texels outside the range of the texture array as it was originally specified. It is not an error to specify a subtexture with width of 0, but such a specification has no effect.

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if format is not an accepted format constant.

GL_INVALID_ENUM is generated if type is not a type constant.

GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2max, where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if xoffset<-b, or if (xoffset+width,)>(w-b,), where w is the GL_TEXTURE_WIDTH, and b is the width of the GL_TEXTURE_BORDER of the texture image being modified. Note that w includes twice the border width.

GL_INVALID_VALUE is generated if width is less than 0.

GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage1D operation.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glTexSubImage1D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTexSubImage2D target level xoffset yoffset width height format type data

Specify a two-dimensional texture subimage.

target: Specifies the target texture. Must be GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset: Specifies a texel offset in the x direction within the texture array.
yoffset: Specifies a texel offset in the y direction within the texture array.
width: Specifies the width of the texture subimage.
height: Specifies the height of the texture subimage.
format: Specifies the format of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
data: Specifies a pointer to the image data in memory.

glTexSubImage2D redefines a contiguous subregion of an existing two-dimensional texture image. The texels referenced by data replace the portion of the existing texture array with x indices xoffset and xoffset+width-1, inclusive, and y indices yoffset and yoffset+height-1, inclusive. This region may not include any texels outside the range of the texture array as it was originally specified. It is not an error to specify a subtexture with zero width or height, but such a specification has no effect.

GL_INVALID_ENUM is generated if format is not an accepted format constant.

GL_INVALID_ENUM is generated if type is not a type constant.

GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2max, where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if xoffset<-b, (xoffset+width,)>(w-b,), yoffset<-b, or (yoffset+height,)>(h-b,), where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, and b is the border width of the texture image being modified. Note that w and h include twice the border width.

GL_INVALID_VALUE is generated if width or height is less than 0.

GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage2D operation.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glTexSubImage2D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTexSubImage3D target level xoffset yoffset zoffset width height depth format type data

Specify a three-dimensional texture subimage.

target: Specifies the target texture. Must be GL_TEXTURE_3D.
level: Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset: Specifies a texel offset in the x direction within the texture array.
yoffset: Specifies a texel offset in the y direction within the texture array.
zoffset: Specifies a texel offset in the z direction within the texture array.
width: Specifies the width of the texture subimage.
height: Specifies the height of the texture subimage.
depth: Specifies the depth of the texture subimage.
format: Specifies the format of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
type: Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.
data: Specifies a pointer to the image data in memory.

glTexSubImage3D redefines a contiguous subregion of an existing three-dimensional texture image. The texels referenced by data replace the portion of the existing texture array with x indices xoffset and xoffset+width-1, inclusive, y indices yoffset and yoffset+height-1, inclusive, and z indices zoffset and zoffset+depth-1, inclusive. This region may not include any texels outside the range of the texture array as it was originally specified. It is not an error to specify a subtexture with zero width, height, or depth but such a specification has no effect.

GL_INVALID_ENUM is generated if /target is not GL_TEXTURE_3D.

GL_INVALID_ENUM is generated if format is not an accepted format constant.

GL_INVALID_ENUM is generated if type is not a type constant.

GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than log_2max, where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if xoffset<-b, (xoffset+width,)>(w-b,), yoffset<-b, or (yoffset+height,)>(h-b,), or zoffset<-b, or (zoffset+depth,)>(d-b,), where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, d is the GL_TEXTURE_DEPTH and b is the border width of the texture image being modified. Note that w, h, and d include twice the border width.

GL_INVALID_VALUE is generated if width, height, or depth is less than 0.

GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage3D operation.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object’s data store is currently mapped.

GL_INVALID_OPERATION is generated if glTexSubImage3D is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glTranslated x y z

Function: void glTranslatef x y z

Multiply the current matrix by a translation matrix.

x
y
z: Specify the x, y, and z coordinates of a translation vector.

glTranslate produces a translation by (x,yz). The current matrix (see glMatrixMode) is multiplied by this translation matrix, with the product replacing the current matrix, as if glMultMatrix were called with the following matrix for its argument:

((1 0 0 x), (0 1 0 y), (0 0 1 z), (0 0 0 1),)

If the matrix mode is either GL_MODELVIEW or GL_PROJECTION, all objects drawn after a call to glTranslate are translated.

Use glPushMatrix and glPopMatrix to save and restore the untranslated coordinate system.

GL_INVALID_OPERATION is generated if glTranslate is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glUniform1f location v0

Function: void glUniform2f location v0 v1

Function: void glUniform3f location v0 v1 v2

Function: void glUniform4f location v0 v1 v2 v3

Function: void glUniform1i location v0

Function: void glUniform2i location v0 v1

Function: void glUniform3i location v0 v1 v2

Function: void glUniform4i location v0 v1 v2 v3

Function: void glUniform1fv location count value

Function: void glUniform2fv location count value

Function: void glUniform3fv location count value

Function: void glUniform4fv location count value

Function: void glUniform1iv location count value

Function: void glUniform2iv location count value

Function: void glUniform3iv location count value

Function: void glUniform4iv location count value

Function: void glUniformMatrix2fv location count transpose value

Function: void glUniformMatrix3fv location count transpose value

Function: void glUniformMatrix4fv location count transpose value

Function: void glUniformMatrix2x3fv location count transpose value

Function: void glUniformMatrix3x2fv location count transpose value

Function: void glUniformMatrix2x4fv location count transpose value

Function: void glUniformMatrix4x2fv location count transpose value

Function: void glUniformMatrix3x4fv location count transpose value

Function: void glUniformMatrix4x3fv location count transpose value

Specify the value of a uniform variable for the current program object.

location: Specifies the location of the uniform variable to be modified.
v0, v1, v2, v3: Specifies the new values to be used for the specified uniform variable.

glUniform modifies the value of a uniform variable or a uniform variable array. The location of the uniform variable to be modified is specified by location, which should be a value returned by glGetUniformLocation. glUniform operates on the program object that was made part of current state by calling glUseProgram.

The commands glUniform{1|2|3|4}{f|i} are used to change the value of the uniform variable specified by location using the values passed as arguments. The number specified in the command should match the number of components in the data type of the specified uniform variable (e.g., 1 for float, int, bool; 2 for vec2, ivec2, bvec2, etc.). The suffix f indicates that floating-point values are being passed; the suffix i indicates that integer values are being passed, and this type should also match the data type of the specified uniform variable. The i variants of this function should be used to provide values for uniform variables defined as int, ivec2, ivec3, ivec4, or arrays of these. The f variants should be used to provide values for uniform variables of type float, vec2, vec3, vec4, or arrays of these. Either the i or the f variants may be used to provide values for uniform variables of type bool, bvec2, bvec3, bvec4, or arrays of these. The uniform variable will be set to false if the input value is 0 or 0.0f, and it will be set to true otherwise.

All active uniform variables defined in a program object are initialized to 0 when the program object is linked successfully. They retain the values assigned to them by a call to glUniform until the next successful link operation occurs on the program object, when they are once again initialized to 0.

The commands glUniform{1|2|3|4}{f|i}v can be used to modify a single uniform variable or a uniform variable array. These commands pass a count and a pointer to the values to be loaded into a uniform variable or a uniform variable array. A count of 1 should be used if modifying the value of a single uniform variable, and a count of 1 or greater can be used to modify an entire array or part of an array. When loading n elements starting at an arbitrary position m in a uniform variable array, elements m + n - 1 in the array will be replaced with the new values. If m + n - 1 is larger than the size of the uniform variable array, values for all array elements beyond the end of the array will be ignored. The number specified in the name of the command indicates the number of components for each element in value, and it should match the number of components in the data type of the specified uniform variable (e.g., 1 for float, int, bool; 2 for vec2, ivec2, bvec2, etc.). The data type specified in the name of the command must match the data type for the specified uniform variable as described previously for glUniform{1|2|3|4}{f|i}.

For uniform variable arrays, each element of the array is considered to be of the type indicated in the name of the command (e.g., glUniform3f or glUniform3fv can be used to load a uniform variable array of type vec3). The number of elements of the uniform variable array to be modified is specified by count

The commands glUniformMatrix{2|3|4|2x3|3x2|2x4|4x2|3x4|4x3}fv are used to modify a matrix or an array of matrices. The numbers in the command name are interpreted as the dimensionality of the matrix. The number 2 indicates a 2 Ã 2 matrix (i.e., 4 values), the number 3 indicates a 3 Ã 3 matrix (i.e., 9 values), and the number 4 indicates a 4 Ã 4 matrix (i.e., 16 values). Non-square matrix dimensionality is explicit, with the first number representing the number of columns and the second number representing the number of rows. For example, 2x4 indicates a 2 Ã 4 matrix with 2 columns and 4 rows (i.e., 8 values). If transpose is GL_FALSE, each matrix is assumed to be supplied in column major order. If transpose is GL_TRUE, each matrix is assumed to be supplied in row major order. The count argument indicates the number of matrices to be passed. A count of 1 should be used if modifying the value of a single matrix, and a count greater than 1 can be used to modify an array of matrices.

GL_INVALID_OPERATION is generated if there is no current program object.

GL_INVALID_OPERATION is generated if the size of the uniform variable declared in the shader does not match the size indicated by the glUniform command.

GL_INVALID_OPERATION is generated if one of the integer variants of this function is used to load a uniform variable of type float, vec2, vec3, vec4, or an array of these, or if one of the floating-point variants of this function is used to load a uniform variable of type int, ivec2, ivec3, or ivec4, or an array of these.

GL_INVALID_OPERATION is generated if location is an invalid uniform location for the current program object and location is not equal to -1.

GL_INVALID_VALUE is generated if count is less than 0.

GL_INVALID_OPERATION is generated if count is greater than 1 and the indicated uniform variable is not an array variable.

GL_INVALID_OPERATION is generated if a sampler is loaded using a command other than glUniform1i and glUniform1iv.

GL_INVALID_OPERATION is generated if glUniform is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glUseProgram program

Installs a program object as part of current rendering state.

program: Specifies the handle of the program object whose executables are to be used as part of current rendering state.

glUseProgram installs the program object specified by program as part of current rendering state. One or more executables are created in a program object by successfully attaching shader objects to it with glAttachShader, successfully compiling the shader objects with glCompileShader, and successfully linking the program object with glLinkProgram.

A program object will contain an executable that will run on the vertex processor if it contains one or more shader objects of type GL_VERTEX_SHADER that have been successfully compiled and linked. Similarly, a program object will contain an executable that will run on the fragment processor if it contains one or more shader objects of type GL_FRAGMENT_SHADER that have been successfully compiled and linked.

Successfully installing an executable on a programmable processor will cause the corresponding fixed functionality of OpenGL to be disabled. Specifically, if an executable is installed on the vertex processor, the OpenGL fixed functionality will be disabled as follows.

The modelview matrix is not applied to vertex coordinates.
The projection matrix is not applied to vertex coordinates.
The texture matrices are not applied to texture coordinates.
Normals are not transformed to eye coordinates.
Normals are not rescaled or normalized.
Normalization of GL_AUTO_NORMAL evaluated normals is not performed.
Texture coordinates are not generated automatically.
Per-vertex lighting is not performed.
Color material computations are not performed.
Color index lighting is not performed.
This list also applies when setting the current raster position.

The executable that is installed on the vertex processor is expected to implement any or all of the desired functionality from the preceding list. Similarly, if an executable is installed on the fragment processor, the OpenGL fixed functionality will be disabled as follows.

Texture environment and texture functions are not applied.
Texture application is not applied.
Color sum is not applied.
Fog is not applied.

Again, the fragment shader that is installed is expected to implement any or all of the desired functionality from the preceding list.

While a program object is in use, applications are free to modify attached shader objects, compile attached shader objects, attach additional shader objects, and detach or delete shader objects. None of these operations will affect the executables that are part of the current state. However, relinking the program object that is currently in use will install the program object as part of the current rendering state if the link operation was successful (see glLinkProgram ). If the program object currently in use is relinked unsuccessfully, its link status will be set to GL_FALSE, but the executables and associated state will remain part of the current state until a subsequent call to glUseProgram removes it from use. After it is removed from use, it cannot be made part of current state until it has been successfully relinked.

If program contains shader objects of type GL_VERTEX_SHADER but it does not contain shader objects of type GL_FRAGMENT_SHADER, an executable will be installed on the vertex processor, but fixed functionality will be used for fragment processing. Similarly, if program contains shader objects of type GL_FRAGMENT_SHADER but it does not contain shader objects of type GL_VERTEX_SHADER, an executable will be installed on the fragment processor, but fixed functionality will be used for vertex processing. If program is 0, the programmable processors will be disabled, and fixed functionality will be used for both vertex and fragment processing.

GL_INVALID_VALUE is generated if program is neither 0 nor a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_OPERATION is generated if program could not be made part of current state.

GL_INVALID_OPERATION is generated if glUseProgram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glValidateProgram program

Validates a program object.

program: Specifies the handle of the program object to be validated.

glValidateProgram checks to see whether the executables contained in program can execute given the current OpenGL state. The information generated by the validation process will be stored in program’s information log. The validation information may consist of an empty string, or it may be a string containing information about how the current program object interacts with the rest of current OpenGL state. This provides a way for OpenGL implementers to convey more information about why the current program is inefficient, suboptimal, failing to execute, and so on.

The status of the validation operation will be stored as part of the program object’s state. This value will be set to GL_TRUE if the validation succeeded, and GL_FALSE otherwise. It can be queried by calling glGetProgram with arguments program and GL_VALIDATE_STATUS. If validation is successful, program is guaranteed to execute given the current state. Otherwise, program is guaranteed to not execute.

This function is typically useful only during application development. The informational string stored in the information log is completely implementation dependent; therefore, an application should not expect different OpenGL implementations to produce identical information strings.

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program is not a program object.

GL_INVALID_OPERATION is generated if glValidateProgram is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glVertexAttribPointer index size type normalized stride pointer

Define an array of generic vertex attribute data.

index: Specifies the index of the generic vertex attribute to be modified.
size: Specifies the number of components per generic vertex attribute. Must be 1, 2, 3, or 4. The initial value is 4.
type: Specifies the data type of each component in the array. Symbolic constants GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT, GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
normalized: Specifies whether fixed-point data values should be normalized (GL_TRUE) or converted directly as fixed-point values (GL_FALSE) when they are accessed.
stride: Specifies the byte offset between consecutive generic vertex attributes. If stride is 0, the generic vertex attributes are understood to be tightly packed in the array. The initial value is 0.
pointer: Specifies a pointer to the first component of the first generic vertex attribute in the array. The initial value is 0.

glVertexAttribPointer specifies the location and data format of the array of generic vertex attributes at index index to use when rendering. size specifies the number of components per attribute and must be 1, 2, 3, or 4. type specifies the data type of each component, and stride specifies the byte stride from one attribute to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays. If set to GL_TRUE, normalized indicates that values stored in an integer format are to be mapped to the range [-1,1] (for signed values) or [0,1] (for unsigned values) when they are accessed and converted to floating point. Otherwise, values will be converted to floats directly without normalization.

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer) while a generic vertex attribute array is specified, pointer is treated as a byte offset into the buffer object’s data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as generic vertex attribute array client-side state (GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING) for index index.

When a generic vertex attribute array is specified, size, type, normalized, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable a generic vertex attribute array, call glEnableVertexAttribArray and glDisableVertexAttribArray with index. If enabled, the generic vertex attribute array is used when glArrayElement, glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, or glDrawRangeElements is called.

GL_INVALID_VALUE is generated if index is greater than or equal to GL_MAX_VERTEX_ATTRIBS.

GL_INVALID_VALUE is generated if size is not 1, 2, 3, or 4.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if stride is negative.

Function: void glVertexAttrib1f index v0

Function: void glVertexAttrib1s index v0

Function: void glVertexAttrib1d index v0

Function: void glVertexAttrib2f index v0 v1

Function: void glVertexAttrib2s index v0 v1

Function: void glVertexAttrib2d index v0 v1

Function: void glVertexAttrib3f index v0 v1 v2

Function: void glVertexAttrib3s index v0 v1 v2

Function: void glVertexAttrib3d index v0 v1 v2

Function: void glVertexAttrib4f index v0 v1 v2 v3

Function: void glVertexAttrib4s index v0 v1 v2 v3

Function: void glVertexAttrib4d index v0 v1 v2 v3

Function: void glVertexAttrib4Nub index v0 v1 v2 v3

Function: void glVertexAttrib1fv index v

Function: void glVertexAttrib1sv index v

Function: void glVertexAttrib1dv index v

Function: void glVertexAttrib2fv index v

Function: void glVertexAttrib2sv index v

Function: void glVertexAttrib2dv index v

Function: void glVertexAttrib3fv index v

Function: void glVertexAttrib3sv index v

Function: void glVertexAttrib3dv index v

Function: void glVertexAttrib4fv index v

Function: void glVertexAttrib4sv index v

Function: void glVertexAttrib4dv index v

Function: void glVertexAttrib4iv index v

Function: void glVertexAttrib4bv index v

Function: void glVertexAttrib4ubv index v

Function: void glVertexAttrib4usv index v

Function: void glVertexAttrib4uiv index v

Function: void glVertexAttrib4Nbv index v

Function: void glVertexAttrib4Nsv index v

Function: void glVertexAttrib4Niv index v

Function: void glVertexAttrib4Nubv index v

Function: void glVertexAttrib4Nusv index v

Function: void glVertexAttrib4Nuiv index v

Specifies the value of a generic vertex attribute.

index: Specifies the index of the generic vertex attribute to be modified.
v0, v1, v2, v3: Specifies the new values to be used for the specified vertex attribute.

OpenGL defines a number of standard vertex attributes that applications can modify with standard API entry points (color, normal, texture coordinates, etc.). The glVertexAttrib family of entry points allows an application to pass generic vertex attributes in numbered locations.

Generic attributes are defined as four-component values that are organized into an array. The first entry of this array is numbered 0, and the size of the array is specified by the implementation-dependent constant GL_MAX_VERTEX_ATTRIBS. Individual elements of this array can be modified with a glVertexAttrib call that specifies the index of the element to be modified and a value for that element.

These commands can be used to specify one, two, three, or all four components of the generic vertex attribute specified by index. A 1 in the name of the command indicates that only one value is passed, and it will be used to modify the first component of the generic vertex attribute. The second and third components will be set to 0, and the fourth component will be set to 1. Similarly, a 2 in the name of the command indicates that values are provided for the first two components, the third component will be set to 0, and the fourth component will be set to 1. A 3 in the name of the command indicates that values are provided for the first three components and the fourth component will be set to 1, whereas a 4 in the name indicates that values are provided for all four components.

The letters s, f, i, d, ub, us, and ui indicate whether the arguments are of type short, float, int, double, unsigned byte, unsigned short, or unsigned int. When v is appended to the name, the commands can take a pointer to an array of such values. The commands containing N indicate that the arguments will be passed as fixed-point values that are scaled to a normalized range according to the component conversion rules defined by the OpenGL specification. Signed values are understood to represent fixed-point values in the range [-1,1], and unsigned values are understood to represent fixed-point values in the range [0,1].

OpenGL Shading Language attribute variables are allowed to be of type mat2, mat3, or mat4. Attributes of these types may be loaded using the glVertexAttrib entry points. Matrices must be loaded into successive generic attribute slots in column major order, with one column of the matrix in each generic attribute slot.

A user-defined attribute variable declared in a vertex shader can be bound to a generic attribute index by calling glBindAttribLocation. This allows an application to use more descriptive variable names in a vertex shader. A subsequent change to the specified generic vertex attribute will be immediately reflected as a change to the corresponding attribute variable in the vertex shader.

The binding between a generic vertex attribute index and a user-defined attribute variable in a vertex shader is part of the state of a program object, but the current value of the generic vertex attribute is not. The value of each generic vertex attribute is part of current state, just like standard vertex attributes, and it is maintained even if a different program object is used.

An application may freely modify generic vertex attributes that are not bound to a named vertex shader attribute variable. These values are simply maintained as part of current state and will not be accessed by the vertex shader. If a generic vertex attribute bound to an attribute variable in a vertex shader is not updated while the vertex shader is executing, the vertex shader will repeatedly use the current value for the generic vertex attribute.

The generic vertex attribute with index 0 is the same as the vertex position attribute previously defined by OpenGL. A glVertex2, glVertex3, or glVertex4 command is completely equivalent to the corresponding glVertexAttrib command with an index argument of 0. A vertex shader can access generic vertex attribute 0 by using the built-in attribute variable gl_Vertex. There are no current values for generic vertex attribute 0. This is the only generic vertex attribute with this property; calls to set other standard vertex attributes can be freely mixed with calls to set any of the other generic vertex attributes.

GL_INVALID_VALUE is generated if index is greater than or equal to GL_MAX_VERTEX_ATTRIBS.

Function: void glVertexPointer size type stride pointer

Define an array of vertex data.

size: Specifies the number of coordinates per vertex. Must be 2, 3, or 4. The initial value is 4.
type: Specifies the data type of each coordinate in the array. Symbolic constants GL_SHORT, GL_INT, GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.
stride: Specifies the byte offset between consecutive vertices. If stride is 0, the vertices are understood to be tightly packed in the array. The initial value is 0.
pointer: Specifies a pointer to the first coordinate of the first vertex in the array. The initial value is 0.

glVertexPointer specifies the location and data format of an array of vertex coordinates to use when rendering. size specifies the number of coordinates per vertex, and must be 2, 3, or 4. type specifies the data type of each coordinate, and stride specifies the byte stride from one vertex to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on some implementations; see glInterleavedArrays.)

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer) while a vertex array is specified, pointer is treated as a byte offset into the buffer object’s data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as vertex array client-side state (GL_VERTEX_ARRAY_BUFFER_BINDING).

When a vertex array is specified, size, type, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable the vertex array, call glEnableClientState and glDisableClientState with the argument GL_VERTEX_ARRAY. If enabled, the vertex array is used when glArrayElement, glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, or glDrawRangeElements is called.

GL_INVALID_VALUE is generated if size is not 2, 3, or 4.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if stride is negative.

Function: void glVertex2s x y

Function: void glVertex2i x y

Function: void glVertex2f x y

Function: void glVertex2d x y

Function: void glVertex3s x y z

Function: void glVertex3i x y z

Function: void glVertex3f x y z

Function: void glVertex3d x y z

Function: void glVertex4s x y z w

Function: void glVertex4i x y z w

Function: void glVertex4f x y z w

Function: void glVertex4d x y z w

Function: void glVertex2sv v

Function: void glVertex2iv v

Function: void glVertex2fv v

Function: void glVertex2dv v

Function: void glVertex3sv v

Function: void glVertex3iv v

Function: void glVertex3fv v

Function: void glVertex3dv v

Function: void glVertex4sv v

Function: void glVertex4iv v

Function: void glVertex4fv v

Function: void glVertex4dv v

Specify a vertex.

x
y
z
w: Specify x, y, z, and w coordinates of a vertex. Not all parameters are present in all forms of the command.

glVertex commands are used within glBegin/glEnd pairs to specify point, line, and polygon vertices. The current color, normal, texture coordinates, and fog coordinate are associated with the vertex when glVertex is called.

When only x and y are specified, z defaults to 0 and w defaults to 1. When x, y, and z are specified, w defaults to 1.

Function: void glViewport x y width height

Set the viewport.

x
y: Specify the lower left corner of the viewport rectangle, in pixels. The initial value is (0,0).
width
height: Specify the width and height of the viewport. When a GL context is first attached to a window, width and height are set to the dimensions of that window.

glViewport specifies the affine transformation of x and y from normalized device coordinates to window coordinates. Let (x_nd,y_nd) be normalized device coordinates. Then the window coordinates (x_w,y_w) are computed as follows:

x_w=(x_nd+1,)â¢(width/2,)+x

y_w=(y_nd+1,)â¢(height/2,)+y

Viewport width and height are silently clamped to a range that depends on the implementation. To query this range, call glGet with argument GL_MAX_VIEWPORT_DIMS.

GL_INVALID_VALUE is generated if either width or height is negative.

GL_INVALID_OPERATION is generated if glViewport is executed between the execution of glBegin and the corresponding execution of glEnd.

Function: void glWindowPos2s x y

Function: void glWindowPos2i x y

Function: void glWindowPos2f x y

Function: void glWindowPos2d x y

Function: void glWindowPos3s x y z

Function: void glWindowPos3i x y z

Function: void glWindowPos3f x y z

Function: void glWindowPos3d x y z

Function: void glWindowPos2sv v

Function: void glWindowPos2iv v

Function: void glWindowPos2fv v

Function: void glWindowPos2dv v

Function: void glWindowPos3sv v

Function: void glWindowPos3iv v

Function: void glWindowPos3fv v

Function: void glWindowPos3dv v

Specify the raster position in window coordinates for pixel operations.

x
y
z: Specify the x, y, z coordinates for the raster position.

glWindowPos2 specifies the x and y coordinates, while z is implicitly set to 0. glWindowPos3 specifies all three coordinates. The w coordinate of the current raster position is always set to 1.0.

glWindowPos directly updates the x and y coordinates of the current raster position with the values specified. That is, the values are neither transformed by the current modelview and projection matrices, nor by the viewport-to-window transform. The z coordinate of the current raster position is updated in the following manner:

z={(n), (f), (n+zÃ(f-n,),)â¢(ifâ¢z<=0), (ifâ¢z>=1), (otherwise,),

where n is GL_DEPTH_RANGE’s near value, and f is GL_DEPTH_RANGE’s far value. See glDepthRange.

The specified coordinates are not clip-tested, causing the raster position to always be valid.

Likewise, GL_CURRENT_RASTER_TEXTURE_COORDS is updated as a function of GL_CURRENT_TEXTURE_COORDS, based on the texture matrix and the texture generation functions (see glTexGen). The GL_CURRENT_RASTER_DISTANCE is set to the GL_CURRENT_FOG_COORD.

GL_INVALID_OPERATION is generated if glWindowPos is executed between the execution of glBegin and the corresponding execution of glEnd.