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/ IRIX Base Documentation 2001 May / SGI IRIX Base Documentation 2001 May.iso / usr / share / catman / g_man / cat3 / OpenGL / glhint.z / glhint
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Text File  |  2001-04-17  |  11.2 KB  |  199 lines
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  4. ggggllllHHHHiiiinnnntttt((((3333GGGG))))                     OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee                     ggggllllHHHHiiiinnnntttt((((3333GGGG))))
  5.  
  6.  
  7.  
  8. NNNNAAAAMMMMEEEE
  9.      ggggllllHHHHiiiinnnntttt - specify implementation-specific hints
  10.  
  11.  
  12. CCCC SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  13.      void ggggllllHHHHiiiinnnntttt( GLenum _t_a_r_g_e_t,
  14.                   GLenum _m_o_d_e )
  15.  
  16.  
  17. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  18.      _t_a_r_g_e_t  Specifies a symbolic constant indicating the behavior to be
  19.              controlled.  GGGGLLLL____CCCCOOOONNNNVVVVOOOOLLLLUUUUTTTTIIIIOOOONNNN____HHHHIIIINNNNTTTT____SSSSGGGGIIIIXXXX, GGGGLLLL____SSSSCCCCAAAALLLLEEEEBBBBIIIIAAAASSSS____HHHHIIIINNNNTTTT____SSSSGGGGIIIIXXXX,
  20.              GGGGLLLL____FFFFOOOOGGGG____HHHHIIIINNNNTTTT, GGGGLLLL____LLLLIIIINNNNEEEE____SSSSMMMMOOOOOOOOTTTTHHHH____HHHHIIIINNNNTTTT, GGGGLLLL____PPPPEEEERRRRSSSSPPPPEEEECCCCTTTTIIIIVVVVEEEE____CCCCOOOORRRRRRRREEEECCCCTTTTIIIIOOOONNNN____HHHHIIIINNNNTTTT,
  21.              GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSMMMMOOOOOOOOTTTTHHHH____HHHHIIIINNNNTTTT, GGGGLLLL____PPPPOOOOLLLLYYYYGGGGOOOONNNN____SSSSMMMMOOOOOOOOTTTTHHHH____HHHHIIIINNNNTTTT, and
  22.              GGGGLLLL____VVVVEEEERRRRTTTTEEEEXXXX____PPPPRRRREEEECCCCLLLLIIIIPPPP____HHHHIIIINNNNTTTT____SSSSGGGGIIIIXXXX are accepted.
  23.  
  24.      _m_o_d_e    Specifies a symbolic constant indicating the desired behavior.
  25.              GGGGLLLL____FFFFAAAASSSSTTTTEEEESSSSTTTT, GGGGLLLL____NNNNIIIICCCCEEEESSSSTTTT, and GGGGLLLL____DDDDOOOONNNNTTTT____CCCCAAAARRRREEEE are accepted.
  26.  
  27. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  28.      Certain aspects of GL behavior, when there is room for interpretation,
  29.      can be controlled with hints.  A hint is specified with two arguments.
  30.      _t_a_r_g_e_t is a symbolic constant indicating the behavior to be controlled,
  31.      and _m_o_d_e is another symbolic constant indicating the desired behavior.
  32.      The initial value for each _t_a_r_g_e_t is GGGGLLLL____DDDDOOOONNNNTTTT____CCCCAAAARRRREEEE. _m_o_d_e can be one of the
  33.      following:
  34.  
  35.      GGGGLLLL____FFFFAAAASSSSTTTTEEEESSSSTTTT          The most efficient option should be chosen.
  36.  
  37.      GGGGLLLL____NNNNIIIICCCCEEEESSSSTTTT           The most correct, or highest quality, option should
  38.                          be chosen.
  39.  
  40.      GGGGLLLL____DDDDOOOONNNNTTTT____CCCCAAAARRRREEEE        No preference.
  41.  
  42.      Though the implementation aspects that can be hinted are well defined,
  43.      the interpretation of the hints depends on the implementation.  The hint
  44.      aspects that can be specified with _t_a_r_g_e_t, along with suggested
  45.      semantics, are as follows:
  46.  
  47.      GGGGLLLL____CCCCOOOONNNNVVVVOOOOLLLLUUUUTTTTIIIIOOOONNNN____HHHHIIIINNNNTTTT____SSSSGGGGIIIIXXXX
  48.                          Indicates the accuracy of convolution arithmetic.
  49.                          Hinting GGGGLLLL____NNNNIIIICCCCEEEESSSSTTTT yields the most accurate
  50.                          convolution computations at some performance cost.
  51.  
  52.      GGGGLLLL____SSSSCCCCAAAALLLLEEEEBBBBIIIIAAAASSSS____HHHHIIIINNNNTTTT____SSSSGGGGIIIIXXXX
  53.                          Indicates the precision of scaling and biasing
  54.                          arithmetic.  For large scale factors, hinting
  55.                          GGGGLLLL____NNNNIIIICCCCEEEESSSSTTTT provides the most accurate results.
  56.  
  57.      GGGGLLLL____FFFFOOOOGGGG____HHHHIIIINNNNTTTT         Indicates the accuracy of fog calculation.  If per-
  58.                          pixel fog calculation is not efficiently supported by
  59.                          the GL implementation, hinting GGGGLLLL____DDDDOOOONNNNTTTT____CCCCAAAARRRREEEE or
  60.  
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  62.  
  63.                                                                         PPPPaaaaggggeeee 1111
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  70. ggggllllHHHHiiiinnnntttt((((3333GGGG))))                     OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee                     ggggllllHHHHiiiinnnntttt((((3333GGGG))))
  71.  
  72.  
  73.  
  74.                          GGGGLLLL____FFFFAAAASSSSTTTTEEEESSSSTTTT can result in per-vertex calculation of
  75.                          fog effects.
  76.  
  77.      GGGGLLLL____LLLLIIIINNNNEEEE____SSSSMMMMOOOOOOOOTTTTHHHH____HHHHIIIINNNNTTTT Indicates the sampling quality of antialiased lines.
  78.                          If a larger filter function is applied, hinting
  79.                          GGGGLLLL____NNNNIIIICCCCEEEESSSSTTTT can result in more pixel fragments being
  80.                          generated during rasterization,
  81.  
  82.      GGGGLLLL____PPPPEEEERRRRSSSSPPPPEEEECCCCTTTTIIIIVVVVEEEE____CCCCOOOORRRRRRRREEEECCCCTTTTIIIIOOOONNNN____HHHHIIIINNNNTTTT
  83.                          Indicates the quality of color and texture coordinate
  84.                          interpolation.  If perspective-corrected parameter
  85.                          interpolation is not efficiently supported by the GL
  86.                          implementation, hinting GGGGLLLL____DDDDOOOONNNNTTTT____CCCCAAAARRRREEEE or GGGGLLLL____FFFFAAAASSSSTTTTEEEESSSSTTTT
  87.                          can result in simple linear interpolation of colors
  88.                          and/or texture coordinates.
  89.  
  90.      GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSMMMMOOOOOOOOTTTTHHHH____HHHHIIIINNNNTTTT
  91.                          Indicates the sampling quality of antialiased points.
  92.                          If a larger filter function is applied, hinting
  93.                          GGGGLLLL____NNNNIIIICCCCEEEESSSSTTTT can result in more pixel fragments being
  94.                          generated during rasterization,
  95.  
  96.      GGGGLLLL____PPPPOOOOLLLLYYYYGGGGOOOONNNN____SSSSMMMMOOOOOOOOTTTTHHHH____HHHHIIIINNNNTTTT
  97.                          Indicates the sampling quality of antialiased
  98.                          polygons.  Hinting GGGGLLLL____NNNNIIIICCCCEEEESSSSTTTT can result in more pixel
  99.                          fragments being generated during rasterization, if a
  100.                          larger filter function is applied.
  101.  
  102.      GGGGLLLL____VVVVEEEERRRRTTTTEEEEXXXX____PPPPRRRREEEECCCCLLLLIIIIPPPP____HHHHIIIINNNNTTTT____SSSSGGGGIIIIXXXX
  103.                          Indicates the amount of work done to detect vertex
  104.                          data for which primitive preclipping may enhance the
  105.                          precision of parameter interpolation over the area of
  106.                          the primitive.  Hinting GGGGLLLL____NNNNIIIICCCCEEEESSSSTTTT yields the
  107.                          highest-quality parameter interpolation at some
  108.                          performance cost.
  109.  
  110. NNNNOOOOTTTTEEEESSSS
  111.      The interpretation of hints depends on the implementation.  Some
  112.      implementations ignore ggggllllHHHHiiiinnnntttt settings.
  113.  
  114. EEEERRRRRRRROOOORRRRSSSS
  115.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____EEEENNNNUUUUMMMM is generated if either _t_a_r_g_e_t or _m_o_d_e is not an accepted
  116.      value.
  117.  
  118.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN is generated if ggggllllHHHHiiiinnnntttt is executed between the
  119.      execution of ggggllllBBBBeeeeggggiiiinnnn and the corresponding execution of ggggllllEEEEnnnndddd.
  120.  
  121.  
  122. MMMMAAAACCCCHHHHIIIINNNNEEEE DDDDEEEEPPPPEEEENNNNDDDDEEEENNNNCCCCIIIIEEEESSSS
  123.      The SSSSGGGGIIIIXXXX____ccccoooonnnnvvvvoooolllluuuuttttiiiioooonnnn____aaaaccccccccuuuurrrraaaaccccyyyy extension is supported only on OOOOccccttttaaaannnneeee2222 VVVVPPPPrrrroooo
  124.      systems.
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  128.  
  129.                                                                         PPPPaaaaggggeeee 2222
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  136. ggggllllHHHHiiiinnnntttt((((3333GGGG))))                     OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee                     ggggllllHHHHiiiinnnntttt((((3333GGGG))))
  137.  
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  139.  
  140.      IIIInnnnffffiiiinnnniiiitttteeeeRRRReeeeaaaalllliiiittttyyyy systems do not support antialiased lines in color-index
  141.      rendering contexts.  (They are rendered as ordinary lines instead.)
  142.  
  143.      On IIIInnnnffffiiiinnnniiiitttteeeeRRRReeeeaaaalllliiiittttyyyy systems, the GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSMMMMOOOOOOOOTTTTHHHH____HHHHIIIINNNNTTTT hint target
  144.      indicates the sampling quality of multisampled points as well as
  145.      antialiased points. When multisampling is enabled, and the derived point
  146.      size is less than 4.0, hinting GGGGLLLL____NNNNIIIICCCCEEEESSSSTTTT yields location-invariant
  147.      points.  In this case the number of samples for a given point is
  148.      determined solely by the derived point size.
  149.  
  150.      The SSSSGGGGIIIIXXXX____vvvveeeerrrrtttteeeexxxx____pppprrrreeeecccclllliiiipppp extension is supported only on OOOOccccttttaaaannnneeee2222 VVVVPPPPrrrroooo
  151.      systems.
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  195.                                                                         PPPPaaaaggggeeee 3333
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