home *** CD-ROM | disk | FTP | other *** search
/ SGI Developer Toolbox 6.1 / SGI Developer Toolbox 6.1 - Disc 1.iso / toolbox / documents / OpenGL / extensions / man / glblendequationext.z / glblendequationext
Encoding:
Text File  |  1996-11-11  |  11.7 KB  |  199 lines

  1.  
  2.  
  3.  
  4. ggggllllBBBBlllleeeennnnddddEEEEqqqquuuuaaaattttiiiioooonnnnEEEEXXXXTTTT((((3333GGGG))))         OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee         ggggllllBBBBlllleeeennnnddddEEEEqqqquuuuaaaattttiiiioooonnnnEEEEXXXXTTTT((((3333GGGG))))
  5.  
  6.  
  7.  
  8. NNNNAAAAMMMMEEEE
  9.      ggggllllBBBBlllleeeennnnddddEEEEqqqquuuuaaaattttiiiioooonnnnEEEEXXXXTTTT - set the blend equation
  10.  
  11.  
  12. CCCC SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  13.      void ggggllllBBBBlllleeeennnnddddEEEEqqqquuuuaaaattttiiiioooonnnnEEEEXXXXTTTT( GLenum _m_o_d_e )
  14.  
  15.  
  16. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  17.      _m_o_d_e specify how source and destination colors
  18.            are combined.
  19.  
  20.  
  21. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  22.      The blend equation determines how the source and destination colors
  23.      factors are combined.  The blend equations of GGGGLLLL____MMMMIIIINNNN____EEEEXXXXTTTT, GGGGLLLL____MMMMAAAAXXXX____EEEEXXXXTTTT, and
  24.      GGGGLLLL____LLLLOOOOGGGGIIIICCCC____OOOOPPPP are simpler, and don't require the use of a source or
  25.      destination factor.
  26.  
  27.      GGGGLLLL____MMMMIIIINNNN____EEEEXXXXTTTT
  28.           sets the blend equation so that each component of the the resultant
  29.           color is the minimum of the corresponding component of the source
  30.           and destination color.
  31.  
  32.      GGGGLLLL____MMMMAAAAXXXX____EEEEXXXXTTTT
  33.           sets the blend equation so that each component of the the resultant
  34.           color is the maximum of the corresponding component of the source
  35.           and destination color.
  36.  
  37.      GGGGLLLL____LLLLOOOOGGGGIIIICCCC____OOOOPPPP
  38.           sets the blend equation so that each component of the resultant
  39.           color is a bitwise logical combination of the corresponding colors
  40.           of the source and destination colors.  The bitwise logical operator
  41.           is specified with the ggggllllLLLLooooggggiiiiccccOOOOpppp command.
  42.  
  43.      The other blend equations are more complex, and do use the source and
  44.      destination blend factors. They are described below. (see ggggllllBBBBlllleeeennnnddddFFFFuuuunnnncccc for
  45.      a description of the various blend factors). In the equations that
  46.      follow, source and destination color components are referred to as
  47.      (Rs,Gs,Bs,As) and (Rd,Gd,Bd,Ad).  The resultant color is referred to as
  48.      (Rr,Gr,Br,Ar)  The source and destination factors are denoted
  49.      (sR,sG,sB,sA) and (dR,dG,dB,dA).  For these equations all color
  50.      components are understood to have integer values between zero and 1.0.
  51.  
  52.      GGGGLLLL____FFFFUUUUNNNNCCCC____AAAADDDDDDDD____EEEEXXXXTTTT
  53.           sets the equation so that the source and destination data is added.
  54.           Each component of the source color is multiplied by the source
  55.           factor, then each component of the destination color is multiplied
  56.           by the destination factor. Finally, the two resulting colors are
  57.           added componentwise.  (see ggggllllBBBBlllleeeennnnddddFFFFuuuunnnncccc for a precise description of
  58.           how to a blend factor.).
  59.  
  60.  
  61.  
  62.  
  63.                                                                         PPPPaaaaggggeeee 1111
  64.  
  65.  
  66.  
  67.  
  68.  
  69.  
  70. ggggllllBBBBlllleeeennnnddddEEEEqqqquuuuaaaattttiiiioooonnnnEEEEXXXXTTTT((((3333GGGG))))         OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee         ggggllllBBBBlllleeeennnnddddEEEEqqqquuuuaaaattttiiiioooonnnnEEEEXXXXTTTT((((3333GGGG))))
  71.  
  72.  
  73.  
  74.                              Rr = min(1,  Rs sR  +  Rd dR)
  75.                              Gr = min(1,  Gs sG  +  Gd dG)
  76.                              Br = min(1,  Bs sB  +  Bd dB)
  77.                              Ar = min(1,  As sA  +  Ad dA)
  78.  
  79.      GGGGLLLL____FFFFUUUUNNNNCCCC____SSSSUUUUBBBBTTTTRRRRAAAACCCCTTTT____EEEEXXXXTTTT
  80.           Is like GGGGLLLL____FFFFUUUUNNNNCCCC____AAAADDDDDDDD____EEEEXXXXTTTT except product of the destination factor and
  81.           the destination color is componentwise subtracted from the product
  82.           of the source factor and the source color.  (see ggggllllBBBBlllleeeennnnddddFFFFuuuunnnncccc for a
  83.           precise description of how to define a factor.).
  84.                              Rr = max(0,  Rs sR  -  Rd dR)
  85.                              Gr = max(0,  Gs sG  -  Gd dG)
  86.                              Br = max(0,  Bs sB  -  Bd dB)
  87.                              Ar = max(0,  As sA  -  Ad dA)
  88.  
  89.      GGGGLLLL____FFFFUUUUNNNNCCCC____RRRREEEEVVVVEEEERRRRSSSSEEEE____SSSSUUUUBBBBTTTTRRRRAAAACCCCTTTT____EEEEXXXXTTTT
  90.           Is like GGGGLLLL____FFFFUUUUNNNNCCCC____AAAADDDDDDDD____EEEEXXXXTTTT except product of the source factor and the
  91.           source color is componentwise subtracted from the product of the
  92.           destination factor and the destination color.  (see ggggllllBBBBlllleeeennnnddddFFFFuuuunnnncccc for
  93.           a precise description of how to multiply a color by a factor.).
  94.                              Rr = max(0,  Rd dR  -  Rs sR)
  95.                              Gr = max(0,  Gd dG  -  Gs sG)
  96.                              Br = max(0,  Bd dB  -  Bs sB)
  97.                              Ar = max(0,  Ad dA  -  As sA)
  98.  
  99.  
  100.      After the source and destination data is combined,  the components of the
  101.      final color is clamped to [0,1].  The min, max, and logicop equations are
  102.      useful for applications, which analyse image data. The GGGGLLLL____FFFFUUUUNNNNCCCC____AAAADDDDDDDD____EEEEXXXXTTTT
  103.      equation  is useful for anti-aliasing and transparency, among other
  104.      things.
  105.  
  106.      Initially the blend equation is set to GGGGLLLL____FFFFUUUUNNNNCCCC____AAAADDDDDDDD____EEEEXXXXTTTT.
  107.  
  108. NNNNOOOOTTTTEEEESSSS
  109.      The GGGGLLLL____MMMMIIIINNNN____EEEEXXXXTTTT, GGGGLLLL____MMMMAAAAXXXX____EEEEXXXXTTTT, and GGGGLLLL____LLLLOOOOGGGGIIIICCCC____OOOOPPPP equations do not use the
  110.      source or destination factors, only the source and destination colors.
  111.  
  112. EEEERRRRRRRROOOORRRRSSSS
  113.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____EEEENNNNUUUUMMMM is generated if _m_o_d_e is not one of GGGGLLLL____FFFFUUUUNNNNCCCC____AAAADDDDDDDD____EEEEXXXXTTTT,
  114.      GGGGLLLL____FFFFUUUUNNNNCCCC____SSSSUUUUBBBBTTTTRRRRAAAACCCCTTTT____EEEEXXXXTTTT, GGGGLLLL____FFFFUUUUNNNNCCCC____RRRREEEEVVVVEEEERRRRSSSSEEEE____SSSSUUUUBBBBTTTTRRRRAAAACCCCTTTT____EEEEXXXXTTTT, GGGGLLLL____MMMMAAAAXXXX____EEEEXXXXTTTT,
  115.      GGGGLLLL____MMMMIIIINNNN____EEEEXXXXTTTT, or GGGGLLLL____LLLLOOOOGGGGIIIICCCC____OOOOPPPP.
  116.  
  117.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN is generated if ggggllllBBBBlllleeeennnnddddEEEEqqqquuuuaaaattttiiiioooonnnnEEEEXXXXTTTT is executed
  118.      between the execution of ggggllllBBBBeeeeggggiiiinnnn and the corresponding execution of
  119.      ggggllllEEEEnnnndddd.
  120.  
  121. AAAASSSSSSSSOOOOCCCCIIIIAAAATTTTEEEEDDDD GGGGEEEETTTTSSSS
  122.      ggggllllGGGGeeeetttt with an argument of GGGGLLLL____BBBBLLLLEEEENNNNDDDD____EEEEQQQQUUUUAAAATTTTIIIIOOOONNNN____EEEEXXXXTTTT.
  123.  
  124.  
  125.  
  126.  
  127.  
  128.  
  129.                                                                         PPPPaaaaggggeeee 2222
  130.  
  131.  
  132.  
  133.  
  134.  
  135.  
  136. ggggllllBBBBlllleeeennnnddddEEEEqqqquuuuaaaattttiiiioooonnnnEEEEXXXXTTTT((((3333GGGG))))         OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee         ggggllllBBBBlllleeeennnnddddEEEEqqqquuuuaaaattttiiiioooonnnnEEEEXXXXTTTT((((3333GGGG))))
  137.  
  138.  
  139.  
  140.      ggggllllGGGGeeeettttSSSSttttrrrriiiinnnngggg with an argument of GGGGLLLL____EEEEXXXXTTTTEEEENNNNSSSSIIIIOOOONNNNSSSS.
  141.           This feature is not part of standard GL. The extensions string of
  142.           ggggllllGGGGeeeettttSSSSttttrrrriiiinnnngggg will contain the name bbbblllleeeennnndddd____mmmmiiiinnnnmmmmaaaaxxxx if GGGGLLLL____MMMMIIIINNNN____EEEEXXXXTTTT and
  143.           GGGGLLLL____MMMMAAAAXXXX____EEEEXXXXTTTT are supported.  It will contain the name bbbblllleeeennnndddd____llllooooggggiiiicccc____oooopppp
  144.           if GGGGLLLL____LLLLOOOOGGGGIIIICCCC____OOOOPPPP is supported in RGB mode. It will contain the name
  145.           bbbblllleeeennnndddd____ssssuuuubbbbttttrrrraaaacccctttt if GGGGLLLL____FFFFUUUUNNNNCCCC____SSSSUUUUBBBBTTTTRRRRAAAACCCCTTTT____EEEEXXXXTTTT and
  146.           GGGGLLLL____FFFFUUUUNNNNCCCC____RRRREEEEVVVVEEEERRRRSSSSEEEE____SSSSUUUUBBBBTTTTRRRRAAAACCCCTTTT____EEEEXXXXTTTT are supported.
  147.  
  148.  
  149. MMMMAAAACCCCHHHHIIIINNNNEEEE DDDDEEEEPPPPEEEENNNNDDDDEEEENNNNCCCCIIIIEEEESSSS
  150.      RealityEngine, RealityEngine2, and VTX systems do not support the use of
  151.      blend factor GGGGLLLL____SSSSRRRRCCCC____AAAALLLLPPPPHHHHAAAA____SSSSAAAATTTTUUUURRRRAAAATTTTEEEE with blend equation
  152.      GGGGLLLL____FFFFUUUUNNNNCCCC____RRRREEEEVVVVEEEERRRRSSSSEEEE____SSSSUUUUBBBBTTTTRRRRAAAACCCCTTTT____EEEEXXXXTTTT; this combination produces incorrect
  153.      results.
  154.  
  155.  
  156. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  157.      ggggllllGGGGeeeettttSSSSttttrrrriiiinnnngggg, ggggllllBBBBlllleeeennnnddddCCCCoooolllloooorrrrEEEEXXXXTTTT, ggggllllBBBBlllleeeennnnddddFFFFuuuunnnncccc.
  158.  
  159.  
  160.  
  161.  
  162.  
  163.  
  164.  
  165.  
  166.  
  167.  
  168.  
  169.  
  170.  
  171.  
  172.  
  173.  
  174.  
  175.  
  176.  
  177.  
  178.  
  179.  
  180.  
  181.  
  182.  
  183.  
  184.  
  185.  
  186.  
  187.  
  188.  
  189.  
  190.  
  191.  
  192.  
  193.  
  194.  
  195.                                                                         PPPPaaaaggggeeee 3333
  196.  
  197.  
  198.  
  199.