home *** CD-ROM | disk | FTP | other *** search
/ IRIX Base Documentation 2001 May / SGI IRIX Base Documentation 2001 May.iso / usr / share / catman / g_man / cat3 / OpenGL-ftn / fglpointsize.z / fglpointsize
Encoding:
Text File  |  2001-04-17  |  9.0 KB  |  136 lines
  1.  
  2.  
  3.  
  4. ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee((((3333GGGG))))               OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee               ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee((((3333GGGG))))
  5.  
  6.  
  7.  
  8. NNNNAAAAMMMMEEEE
  9.      ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee - specify the diameter of rasterized points
  10.  
  11.  
  12. FFFFOOOORRRRTTTTRRRRAAAANNNN SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  13.      SUBROUTINE ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee( REAL*4 _s_i_z_e )
  14.  
  15.  
  16. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  17.      _s_i_z_e  Specifies the diameter of rasterized points.  The initial value is
  18.            1.
  19.  
  20. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  21.      ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee specifies the rasterized diameter of aliased, antialiased,
  22.      and multisampled points.  Using a point size other than 1 has different
  23.      effects depending on whether point antialiasing is enabled.  Both point
  24.      antialiasing and multisampling may affect the actual point size.  To
  25.      enable and disable point antialiasing, call ffffggggllllEEEEnnnnaaaabbbblllleeee and ffffggggllllDDDDiiiissssaaaabbbblllleeee with
  26.      argument GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSMMMMOOOOOOOOTTTTHHHH.
  27.  
  28.      If point antialiasing and multisampling are both disabled, the actual
  29.      size is determined by rounding the supplied size to the nearest integer.
  30.      (If the rounding results in the value 0, it is as if the point size were
  31.      1.)  If the rounded size is odd, then the center point (x, y) of the
  32.      pixel fragment that represents the point is computed as
  33.  
  34.                             ( | x  | + .5, | y  | + .5)
  35.                                  w            w
  36.  
  37.      where w subscripts indicate window coordinates.  All pixels that lie
  38.      within the square grid of the rounded size centered at (x, y) make up the
  39.      fragment.  If the size is even, the center point is
  40.  
  41.                             ( | x  + .5 |, | y  + .5 |)
  42.                                  w            w
  43.  
  44.      and the rasterized fragment's centers are the half-integer window
  45.      coordinates within the square of the rounded size centered at (x, y).
  46.      All pixel fragments produced in rasterizing a nonantialiased point are
  47.      assigned the same associated data, that of the vertex corresponding to
  48.      the point.
  49.  
  50.      If antialiasing is enabled, then point rasterization produces a fragment
  51.      for each pixel square that intersects the region lying within the circle
  52.      having diameter equal to the current point size and centered at the
  53.      point's (x , y ).  The coverage value for each fragment is the window
  54.                w   w
  55.      coordinate area of the intersection of the circular region with the
  56.      corresponding pixel square.  This value is saved and used in the final
  57.      rasterization step. The data associated with each fragment is the data
  58.      associated with the point being rasterized.
  59.  
  60.      Not all sizes are supported when point antialiasing is enabled. If an
  61.      unsupported size is requested, the nearest supported size is used.  Only
  62.      size 1 is guaranteed to be supported; others depend on the
  63.  
  64.  
  65.  
  66.                                                                         PPPPaaaaggggeeee 1111
  67.  
  68.  
  69.  
  70.  
  71.  
  72.  
  73. ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee((((3333GGGG))))               OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee               ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee((((3333GGGG))))
  74.  
  75.  
  76.  
  77.      implementation.  To query the range of supported sizes and the size
  78.      difference between supported sizes within the range, call ffffggggllllGGGGeeeetttt with
  79.      arguments GGGGLLLL____SSSSMMMMOOOOOOOOTTTTHHHH____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____RRRRAAAANNNNGGGGEEEE and
  80.      GGGGLLLL____SSSSMMMMOOOOOOOOTTTTHHHH____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____GGGGRRRRAAAANNNNUUUULLLLAAAARRRRIIIITTTTYYYY.  For aliased points, query the
  81.      supported ranges and granularity with ffffggggllllGGGGeeeetttt with arguments
  82.      GGGGLLLL____AAAALLLLIIIIAAAASSSSEEEEDDDD____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____RRRRAAAANNNNGGGGEEEE and GGGGLLLL____AAAALLLLIIIIAAAASSSSEEEEDDDD____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____GGGGRRRRAAAANNNNUUUULLLLAAAARRRRIIIITTTTYYYY.
  83.  
  84. NNNNOOOOTTTTEEEESSSS
  85.      The point size specified by ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee is always returned when
  86.      GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE is queried.  Clamping and rounding for aliased and
  87.      antialiased points have no effect on the specified value.
  88.  
  89.      A non-antialiased point size may be clamped to an implementation-
  90.      dependent maximum.  Although this maximum cannot be queried, it must be
  91.      no less than the maximum value for antialiased points, rounded to the
  92.      nearest integer value.
  93.  
  94.      GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____RRRRAAAANNNNGGGGEEEE and GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____GGGGRRRRAAAANNNNUUUULLLLAAAARRRRIIIITTTTYYYY are deprecated in GL
  95.      versions 1.2 and greater.  Their functionality has been replaced by
  96.      GGGGLLLL____SSSSMMMMOOOOOOOOTTTTHHHH____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____RRRRAAAANNNNGGGGEEEE and GGGGLLLL____SSSSMMMMOOOOOOOOTTTTHHHH____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____GGGGRRRRAAAANNNNUUUULLLLAAAARRRRIIIITTTTYYYY.
  97.  
  98. EEEERRRRRRRROOOORRRRSSSS
  99.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____VVVVAAAALLLLUUUUEEEE is generated if _s_i_z_e is less than or equal to 0.
  100.  
  101.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN is generated if ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee is executed between the
  102.      execution of ffffggggllllBBBBeeeeggggiiiinnnn and the corresponding execution of ffffggggllllEEEEnnnndddd.
  103.  
  104. AAAASSSSSSSSOOOOCCCCIIIIAAAATTTTEEEEDDDD GGGGEEEETTTTSSSS
  105.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE
  106.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____AAAALLLLIIIIAAAASSSSEEEEDDDD____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____RRRRAAAANNNNGGGGEEEE
  107.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____AAAALLLLIIIIAAAASSSSEEEEDDDD____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____GGGGRRRRAAAANNNNUUUULLLLAAAARRRRIIIITTTTYYYY
  108.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____SSSSMMMMOOOOOOOOTTTTHHHH____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____RRRRAAAANNNNGGGGEEEE
  109.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____SSSSMMMMOOOOOOOOTTTTHHHH____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____GGGGRRRRAAAANNNNUUUULLLLAAAARRRRIIIITTTTYYYY
  110.      ffffggggllllIIIIssssEEEEnnnnaaaabbbblllleeeedddd with argument GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSMMMMOOOOOOOOTTTTHHHH
  111.  
  112.  
  113.  
  114. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  115.      ffffggggllllEEEEnnnnaaaabbbblllleeee
  116.  
  117.  
  118.  
  119.  
  120.  
  121.  
  122.  
  123.  
  124.  
  125.  
  126.  
  127.  
  128.  
  129.  
  130.  
  131.  
  132.                                                                         PPPPaaaaggggeeee 2222
  133.  
  134.  
  135.  
  136.