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/ IRIX Base Documentation 2002 November / SGI IRIX Base Documentation 2002 November.iso / usr / share / catman / g_man / cat3 / OpenGL / glviewport.z / glviewport
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Text File  |  2002-10-03  |  4.2 KB  |  139 lines
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  4. ggggllllVVVViiiieeeewwwwppppoooorrrrtttt((((3333GGGG))))                 OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee                 ggggllllVVVViiiieeeewwwwppppoooorrrrtttt((((3333GGGG))))
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  8. NNNNAAAAMMMMEEEE
  9.      ggggllllVVVViiiieeeewwwwppppoooorrrrtttt - set the viewport
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  11.  
  12. CCCC SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  13.      void ggggllllVVVViiiieeeewwwwppppoooorrrrtttt( GLint _x,
  14.                       GLint _y,
  15.                       GLsizei _w_i_d_t_h,
  16.                       GLsizei _h_e_i_g_h_t )
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  19. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  20.      _x, _y Specify the lower left corner of the viewport rectangle, in pixels.
  21.           The initial value is (0,0).
  22.  
  23.      _w_i_d_t_h, _h_e_i_g_h_t
  24.           Specify the width and height of the viewport.  When a GL context is
  25.           first attached to a window, _w_i_d_t_h and _h_e_i_g_h_t are set to the
  26.           dimensions of that window.
  27.  
  28. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  29.      ggggllllVVVViiiieeeewwwwppppoooorrrrtttt specifies the affine transformation of x and y from normalized
  30.      device coordinates to window coordinates.  Let (x  , y  ) be normalized
  31.                                                       nd   nd
  32.      device coordinates.  Then the window coordinates (x , y ) are computed as
  33.                                                         w   w
  34.      follows:
  35.  
  36.                                            (    width_____)
  37.                              x  = (x   + 1)        + x
  38.                               w     nd     (  2  )
  39.  
  40.                                           (    height______)
  41.                             y  = (y   + 1)         + y
  42.                              w     nd     (  2   )
  43.  
  44.      Viewport width and height are silently clamped to a range that depends on
  45.      the implementation.  To query this range, call ggggllllGGGGeeeetttt with argument
  46.      GGGGLLLL____MMMMAAAAXXXX____VVVVIIIIEEEEWWWWPPPPOOOORRRRTTTT____DDDDIIIIMMMMSSSS.
  47.  
  48. EEEERRRRRRRROOOORRRRSSSS
  49.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____VVVVAAAALLLLUUUUEEEE is generated if either _w_i_d_t_h or _h_e_i_g_h_t is negative.
  50.  
  51.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN is generated if ggggllllVVVViiiieeeewwwwppppoooorrrrtttt is executed between the
  52.      execution of ggggllllBBBBeeeeggggiiiinnnn and the corresponding execution of ggggllllEEEEnnnndddd.
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  69.                                                                         PPPPaaaaggggeeee 1111
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  76. ggggllllVVVViiiieeeewwwwppppoooorrrrtttt((((3333GGGG))))                 OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee                 ggggllllVVVViiiieeeewwwwppppoooorrrrtttt((((3333GGGG))))
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  80. AAAASSSSSSSSOOOOCCCCIIIIAAAATTTTEEEEDDDD GGGGEEEETTTTSSSS
  81.      ggggllllGGGGeeeetttt with argument GGGGLLLL____VVVVIIIIEEEEWWWWPPPPOOOORRRRTTTT
  82.      ggggllllGGGGeeeetttt with argument GGGGLLLL____MMMMAAAAXXXX____VVVVIIIIEEEEWWWWPPPPOOOORRRRTTTT____DDDDIIIIMMMMSSSS
  83.  
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  85. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  86.      ggggllllDDDDeeeepppptttthhhhRRRRaaaannnnggggeeee
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  135.                                                                         PPPPaaaaggggeeee 2222
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