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/ IRIX Base Documentation 2001 May / SGI IRIX Base Documentation 2001 May.iso / usr / share / catman / g_man / cat3 / OpenGL / glrendermode.z / glrendermode
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Text File  |  2001-04-17  |  8.3 KB  |  133 lines
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  4. ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee((((3333GGGG))))               OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee               ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee((((3333GGGG))))
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  7.  
  8. NNNNAAAAMMMMEEEE
  9.      ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee - set rasterization mode
  10.  
  11.  
  12. CCCC SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  13.      GLint ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee( GLenum _m_o_d_e )
  14.  
  15.  
  16. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  17.      _m_o_d_e  Specifies the rasterization mode.  Three values are accepted:
  18.            GGGGLLLL____RRRREEEENNNNDDDDEEEERRRR, GGGGLLLL____SSSSEEEELLLLEEEECCCCTTTT, and GGGGLLLL____FFFFEEEEEEEEDDDDBBBBAAAACCCCKKKK.  The initial value is
  19.            GGGGLLLL____RRRREEEENNNNDDDDEEEERRRR.
  20.  
  21. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  22.      ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee sets the rasterization mode.  It takes one argument, _m_o_d_e,
  23.      which can assume one of three predefined values:
  24.  
  25.      GGGGLLLL____RRRREEEENNNNDDDDEEEERRRR       Render mode. Primitives are rasterized, producing pixel
  26.                      fragments, which are written into the frame buffer.  This
  27.                      is the normal mode and also the default mode.
  28.  
  29.      GGGGLLLL____SSSSEEEELLLLEEEECCCCTTTT       Selection mode.  No pixel fragments are produced, and no
  30.                      change to the frame buffer contents is made.  Instead, a
  31.                      record of the names of primitives that would have been
  32.                      drawn if the render mode had been GGGGLLLL____RRRREEEENNNNDDDDEEEERRRR is returned
  33.                      in a select buffer, which must be created (see
  34.                      ggggllllSSSSeeeelllleeeeccccttttBBBBuuuuffffffffeeeerrrr) before selection mode is entered.
  35.  
  36.      GGGGLLLL____FFFFEEEEEEEEDDDDBBBBAAAACCCCKKKK     Feedback mode.  No pixel fragments are produced, and no
  37.                      change to the frame buffer contents is made.  Instead,
  38.                      the coordinates and attributes of vertices that would
  39.                      have been drawn if the render mode had been GGGGLLLL____RRRREEEENNNNDDDDEEEERRRR is
  40.                      returned in a feedback buffer, which must be created (see
  41.                      ggggllllFFFFeeeeeeeeddddbbbbaaaacccckkkkBBBBuuuuffffffffeeeerrrr) before feedback mode is entered.
  42.  
  43.      The return value of ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee is determined by the render mode at the
  44.      time ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee is called, rather than by _m_o_d_e.  The values returned
  45.      for the three render modes are as follows:
  46.  
  47.      GGGGLLLL____RRRREEEENNNNDDDDEEEERRRR       0.
  48.  
  49.      GGGGLLLL____SSSSEEEELLLLEEEECCCCTTTT       The number of hit records transferred to the select
  50.                      buffer.
  51.  
  52.      GGGGLLLL____FFFFEEEEEEEEDDDDBBBBAAAACCCCKKKK     The number of values (not vertices) transferred to the
  53.                      feedback buffer.
  54.  
  55.      See the ggggllllSSSSeeeelllleeeeccccttttBBBBuuuuffffffffeeeerrrr and ggggllllFFFFeeeeeeeeddddbbbbaaaacccckkkkBBBBuuuuffffffffeeeerrrr reference pages for more
  56.      details concerning selection and feedback operation.
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  62.  
  63.                                                                         PPPPaaaaggggeeee 1111
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  70. ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee((((3333GGGG))))               OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee               ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee((((3333GGGG))))
  71.  
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  73.  
  74. NNNNOOOOTTTTEEEESSSS
  75.      If an error is generated, ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee returns 0 regardless of the
  76.      current render mode.
  77.  
  78.      One particularly surprising error condition occurs when the selection or
  79.      feedback buffer is too large for the implementation to handle.  The
  80.      problem might not be detected until ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee is executed, because
  81.      buffer memory might not be allocated or locked down until that time.  In
  82.      such a case, it is possible that the only indication of the error is that
  83.      ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee will return zero.  Thus it is especially important to check
  84.      the return value.
  85.  
  86. EEEERRRRRRRROOOORRRRSSSS
  87.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____EEEENNNNUUUUMMMM is generated if _m_o_d_e is not one of the three accepted
  88.      values.
  89.  
  90.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN is generated if ggggllllSSSSeeeelllleeeeccccttttBBBBuuuuffffffffeeeerrrr is called while the
  91.      render mode is GGGGLLLL____SSSSEEEELLLLEEEECCCCTTTT, or if ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee is called with argument
  92.      GGGGLLLL____SSSSEEEELLLLEEEECCCCTTTT before ggggllllSSSSeeeelllleeeeccccttttBBBBuuuuffffffffeeeerrrr is called at least once.
  93.  
  94.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN is generated if ggggllllFFFFeeeeeeeeddddbbbbaaaacccckkkkBBBBuuuuffffffffeeeerrrr is called while the
  95.      render mode is GGGGLLLL____FFFFEEEEEEEEDDDDBBBBAAAACCCCKKKK, or if ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee is called with argument
  96.      GGGGLLLL____FFFFEEEEEEEEDDDDBBBBAAAACCCCKKKK before ggggllllFFFFeeeeeeeeddddbbbbaaaacccckkkkBBBBuuuuffffffffeeeerrrr is called at least once.
  97.  
  98.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN is generated if ggggllllRRRReeeennnnddddeeeerrrrMMMMooooddddeeee is executed between the
  99.      execution of ggggllllBBBBeeeeggggiiiinnnn and the corresponding execution of ggggllllEEEEnnnndddd.
  100.  
  101. AAAASSSSSSSSOOOOCCCCIIIIAAAATTTTEEEEDDDD GGGGEEEETTTTSSSS
  102.      ggggllllGGGGeeeetttt with argument GGGGLLLL____RRRREEEENNNNDDDDEEEERRRR____MMMMOOOODDDDEEEE
  103.  
  104.  
  105. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  106.      ggggllllFFFFeeeeeeeeddddbbbbaaaacccckkkkBBBBuuuuffffffffeeeerrrr, ggggllllIIIInnnniiiittttNNNNaaaammmmeeeessss, ggggllllLLLLooooaaaaddddNNNNaaaammmmeeee, ggggllllPPPPaaaassssssssTTTThhhhrrrroooouuuugggghhhh, ggggllllPPPPuuuusssshhhhNNNNaaaammmmeeee,
  107.      ggggllllSSSSeeeelllleeeeccccttttBBBBuuuuffffffffeeeerrrr
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  129.                                                                         PPPPaaaaggggeeee 2222
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