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Text File  |  2002-10-03  |  3.9 KB  |  133 lines
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  4. gggglllluuuuPPPPrrrroooojjjjeeeecccctttt((((3333GGGG))))                 OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee                 gggglllluuuuPPPPrrrroooojjjjeeeecccctttt((((3333GGGG))))
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  8. NNNNAAAAMMMMEEEE
  9.      gggglllluuuuPPPPrrrroooojjjjeeeecccctttt - map object coordinates to window coordinates
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  12. CCCC SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  13.      GLint gggglllluuuuPPPPrrrroooojjjjeeeecccctttt( GLdouble _o_b_j_X,
  14.                        GLdouble _o_b_j_Y,
  15.                        GLdouble _o_b_j_Z,
  16.                        const GLdouble *_m_o_d_e_l,
  17.                        const GLdouble *_p_r_o_j,
  18.                        const GLint *_v_i_e_w,
  19.                        GLdouble* _w_i_n_X,
  20.                        GLdouble* _w_i_n_Y,
  21.                        GLdouble* _w_i_n_Z )
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  24. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  25.      _o_b_j_X, _o_b_j_Y, _o_b_j_Z
  26.                      Specify the object coordinates.
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  28.      _m_o_d_e_l           Specifies the current modelview matrix (as from a
  29.                      ggggllllGGGGeeeettttDDDDoooouuuubbbblllleeeevvvv call).
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  31.      _p_r_o_j            Specifies the current projection matrix (as from a
  32.                      ggggllllGGGGeeeettttDDDDoooouuuubbbblllleeeevvvv call).
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  34.      _v_i_e_w            Specifies the current viewport (as from a ggggllllGGGGeeeettttIIIInnnntttteeeeggggeeeerrrrvvvv
  35.                      call).
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  37.      _w_i_n_X, _w_i_n_Y, _w_i_n_Z
  38.                      Return the computed window coordinates.
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  40. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  41.      gggglllluuuuPPPPrrrroooojjjjeeeecccctttt transforms the specified object coordinates into window
  42.      coordinates using _m_o_d_e_l, _p_r_o_j, and _v_i_e_w. The result is stored in _w_i_n_X,
  43.      _w_i_n_Y, and _w_i_n_Z. A return value of GGGGLLLL____TTTTRRRRUUUUEEEE indicates success, a return
  44.      value of GGGGLLLL____FFFFAAAALLLLSSSSEEEE indicates failure.
  45.  
  46.      To compute the coordinates, let v = (objX,objY,objZ,1.0) represented as a
  47.      matrix with 4 rows and 1 column.  Then gggglllluuuuPPPPrrrroooojjjjeeeecccctttt computes v' as follows:
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  49.      v' = P x M x v
  50.  
  51.      where P is the current projection matrix _p_r_o_j, M is the current modelview
  52.      matrix _m_o_d_e_l (both represented as 4x4 matrices in column-major order) and
  53.      'x' represents matrix multiplication.
  54.  
  55.      The window coordinates are then computed as follows:
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  57.      winX = view(0) + view(2) * (v'(0) + 1) / 2
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  63.                                                                         PPPPaaaaggggeeee 1111
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  70. gggglllluuuuPPPPrrrroooojjjjeeeecccctttt((((3333GGGG))))                 OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee                 gggglllluuuuPPPPrrrroooojjjjeeeecccctttt((((3333GGGG))))
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  73.  
  74.      winY = view(1) + view(3) * (v'(1) + 1) / 2
  75.  
  76.      winZ = (v'(2) + 1) / 2
  77.  
  78.  
  79. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  80.      ggggllllGGGGeeeetttt, gggglllluuuuUUUUnnnnPPPPrrrroooojjjjeeeecccctttt
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  129.                                                                         PPPPaaaaggggeeee 2222
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