Function face_text

    ∇ Z←State face_text B;VPos;VAxis;Color_XYZ;Face;Pos
[1]  ⍝
[2]  ⍝⍝ Z is the 2D text (= the facet number) given the 3D position and view axis
[3]  ⍝
[4]  (VPos VAxis)←B ◊ Face←'YOBRGW'⍳(Color_XYZ←State[VPos;])[VAxis]
[5]  Pos←1+(⌽3 3 3⊤¯1+find_initial_pos Color_XYZ)[⌽1 2 3∼(3 1 2 1 2 3)[Face]]
[6]  Z←¯2↑'ULFRBD'[Face] ◊ →(Pos≡2 2)/0   ⍝ Pos≡2 2 is center cube
[7]  Z←¯2↑⍕(8×Face-1)+Z-5<Z←Pos ⌷ Face mirror 3 3⍴⍳9
    ∇