- specify the width of rasterized lines



C SPECIFICATION


PARAMETERS

       _param1  Specifies  the  width  of  rasterized lines.  The
                initial value is 1.


DESCRIPTION

       glLineWidth specifies the rasterized width of both aliased
       and  antialiased  lines.   Using a line width other than 1
       has  different  effects,   depending   on   whether   line
       antialiasing  is  enabled.   To  enable  and  disable line
       antialiasing, call glEnable and  glDisable  with  argument
       GL_LINE_SMOOTH. Line antialiasing is initially disabled.

       If  line  antialiasing  is  disabled,  the actual width is
       determined by rounding the supplied width to  the  nearest
       integer.   (If  the rounding results in the value 0, it is
       as if the line width were 1.)  If |/\x|>=|/\y|,  i  pixels
       are  filled  in each column that is rasterized, where i is
       the rounded value of _param1.   Otherwise,  i  pixels  are
       filled in each row that is rasterized.

       If  antialiasing is enabled, line rasterization produces a
       fragment for each pixel square that intersects the  region
       lying  within the rectangle having width equal to the cur-
       rent line width, length equal to the actual length of  the
       line,  and centered on the mathematical line segment.  The
       coverage value for each fragment is the window  coordinate
       area  of  the  intersection of the rectangular region with
       the corresponding pixel square.  This value is  saved  and
       used in the final rasterization step.

       Not  all widths can be supported when line antialiasing is
       enabled. If an unsupported width is requested, the nearest
       supported width is used.  Only width 1 is guaranteed to be
       supported; others depend on the implementation.  Likewise,
       there  is  a  range  for  aliased line widths as well.  To
       query the range of supported widths and the  size  differ-
       ence between supported widths within the range, call glGet
       with        arguments         GL_ALIASED_LINE_WIDTH_RANGE,
       GL_SMOOTH_LINE_WIDTH_RANGE,
       GL_SMOOTH_LINE_WIDTH_GRANULARITY.


NOTES

       The line width specified by glLineWidth is always returned
       when  GL_LINE_WIDTH is queried.  Clamping and rounding for
       aliased and antialiased lines have no effect on the speci-
       fied value.

       Nonantialiased line width may be clamped to an implementa-
       glGet with argument GL_ALIASED_LINE_WIDTH_RANGE
       glGet with argument GL_SMOOTH_LINE_WIDTH_RANGE
       glGet with argument GL_SMOOTH_LINE_WIDTH_GRANULARITY
       glIsEnabled with argument GL_LINE_SMOOTH


SEE ALSO

       glEnable



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