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/ IRIX Base Documentation 1998 November / IRIX 6.5.2 Base Documentation November 1998.img / usr / share / catman / g_man / cat3 / OpenGL-ftn / fgllinewidth.z / fgllinewidth
Text File  |  1998-10-20  |  7KB  |  133 lines
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  4. ffffggggllllLLLLiiiinnnneeeeWWWWiiiiddddtttthhhh((((3333GGGG))))               OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee               ffffggggllllLLLLiiiinnnneeeeWWWWiiiiddddtttthhhh((((3333GGGG))))
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  8. NNNNAAAAMMMMEEEE
  9.      ffffggggllllLLLLiiiinnnneeeeWWWWiiiiddddtttthhhh - specify the width of rasterized lines
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  12. FFFFOOOORRRRTTTTRRRRAAAANNNN SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  13.      SUBROUTINE ffffggggllllLLLLiiiinnnneeeeWWWWiiiiddddtttthhhh( REAL*4 _w_i_d_t_h )
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  16. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  17.      _w_i_d_t_h  Specifies the width of rasterized lines.  The initial value is 1.
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  19. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  20.      ffffggggllllLLLLiiiinnnneeeeWWWWiiiiddddtttthhhh specifies the rasterized width of both aliased and
  21.      antialiased lines.  Using a line width other than 1 has different
  22.      effects, depending on whether line antialiasing is enabled.  To enable
  23.      and disable line antialiasing, call ffffggggllllEEEEnnnnaaaabbbblllleeee and ffffggggllllDDDDiiiissssaaaabbbblllleeee with
  24.      argument GGGGLLLL____LLLLIIIINNNNEEEE____SSSSMMMMOOOOOOOOTTTTHHHH. Line antialiasing is initially disabled.
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  26.      If line antialiasing is disabled, the actual width is determined by
  27.      rounding the supplied width to the nearest integer.  (If the rounding
  28.      results in the value 0, it is as if the line width were 1.)  If
  29.      | DELTA x | >= | DELTA y |,
  30.      _i pixels are filled in each column that is rasterized, where _i is the
  31.      rounded value of _w_i_d_t_h.  Otherwise, _i pixels are filled in each row that
  32.      is rasterized.
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  34.      If antialiasing is enabled, line rasterization produces a fragment for
  35.      each pixel square that intersects the region lying within the rectangle
  36.      having width equal to the current line width, length equal to the actual
  37.      length of the line, and centered on the mathematical line segment.  The
  38.      coverage value for each fragment is the window coordinate area of the
  39.      intersection of the rectangular region with the corresponding pixel
  40.      square.  This value is saved and used in the final rasterization step.
  41.  
  42.      Not all widths can be supported when line antialiasing is enabled. If an
  43.      unsupported width is requested, the nearest supported width is used.
  44.      Only width 1 is guaranteed to be supported; others depend on the
  45.      implementation.  To query the range of supported widths and the size
  46.      difference between supported widths within the range, call ffffggggllllGGGGeeeetttt with
  47.      arguments GGGGLLLL____LLLLIIIINNNNEEEE____WWWWIIIIDDDDTTTTHHHH____RRRRAAAANNNNGGGGEEEE and GGGGLLLL____LLLLIIIINNNNEEEE____WWWWIIIIDDDDTTTTHHHH____GGGGRRRRAAAANNNNUUUULLLLAAAARRRRIIIITTTTYYYY.
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  49. NNNNOOOOTTTTEEEESSSS
  50.      The line width specified by ffffggggllllLLLLiiiinnnneeeeWWWWiiiiddddtttthhhh is always returned when
  51.      GGGGLLLL____LLLLIIIINNNNEEEE____WWWWIIIIDDDDTTTTHHHH is queried.  Clamping and rounding for aliased and
  52.      antialiased lines have no effect on the specified value.
  53.  
  54.      Nonantialiased line width may be clamped to an implementation-dependent
  55.      maximum.  Although this maximum cannot be queried, it must be no less
  56.      than the maximum value for antialiased lines, rounded to the nearest
  57.      integer value.
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  63.                                                                         PPPPaaaaggggeeee 1111
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  70. ffffggggllllLLLLiiiinnnneeeeWWWWiiiiddddtttthhhh((((3333GGGG))))               OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee               ffffggggllllLLLLiiiinnnneeeeWWWWiiiiddddtttthhhh((((3333GGGG))))
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  74. EEEERRRRRRRROOOORRRRSSSS
  75.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____VVVVAAAALLLLUUUUEEEE is generated if _w_i_d_t_h is less than or equal to 0.
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  77.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN is generated if ffffggggllllLLLLiiiinnnneeeeWWWWiiiiddddtttthhhh is executed between the
  78.      execution of ffffggggllllBBBBeeeeggggiiiinnnn and the corresponding execution of ffffggggllllEEEEnnnndddd.
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  80. AAAASSSSSSSSOOOOCCCCIIIIAAAATTTTEEEEDDDD GGGGEEEETTTTSSSS
  81.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____LLLLIIIINNNNEEEE____WWWWIIIIDDDDTTTTHHHH
  82.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____LLLLIIIINNNNEEEE____WWWWIIIIDDDDTTTTHHHH____RRRRAAAANNNNGGGGEEEE
  83.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____LLLLIIIINNNNEEEE____WWWWIIIIDDDDTTTTHHHH____GGGGRRRRAAAANNNNUUUULLLLAAAARRRRIIIITTTTYYYY
  84.      ffffggggllllIIIIssssEEEEnnnnaaaabbbblllleeeedddd with argument GGGGLLLL____LLLLIIIINNNNEEEE____SSSSMMMMOOOOOOOOTTTTHHHH
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  87. MMMMAAAACCCCHHHHIIIINNNNEEEE DDDDEEEEPPPPEEEENNNNDDDDEEEENNNNCCCCIIIIEEEESSSS
  88.      InfiniteReality systems do not support antialiased lines in color-index
  89.      rendering contexts.  (They are rendered as ordinary lines instead.)
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  92. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  93.      ffffggggllllBBBBlllleeeennnnddddFFFFuuuunnnncccc, ffffggggllllEEEEnnnnaaaabbbblllleeee, ffffggggllllHHHHiiiinnnntttt
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  129.                                                                         PPPPaaaaggggeeee 2222
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