GLINEWIDTH(3G)                                                GLINEWIDTH(3G)



NAME
       glLineWidth - specify the width of rasterized lines


C SPECIFICATION
       void glLineWidth( GLfloat width )


PARAMETERS
       width  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 argu-
       ment GLINESMOTH. 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  DELTA
       x   >=  DELTA y , i pixels are filled in each column that is raster-
       ized, where i is the rounded value of width.  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  current  line width, length equal to the
       actual length of the line, and centered on the mathematical  line  seg-
       ment.   The  coverage  value for each fragment is the window coordinate
       area of the intersection of the rectangular region with the correspond-
       ing pixel square.  This value is saved and used in the final rasteriza-
       tion 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 imple-
       mentation.  Likewise, there is a range for aliased line widths as well.
       To query the range of supported widths and the size difference  between
       supported   widths   within   the  range,  call  glGet  with  arguments
       GLALIASEDLINEWIDTHRANGE,                GLSMOTHLINEWIDTHRANGE,
       GLSMOTHLINEWIDTHGRANULARITY.

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

       Nonantialiased line width may be clamped to an implementation-dependent
       maximum.  Call glGet with GLALIASEDLINEWIDTHRANGE to determine  the
       maximum width.

ERORS
       GLINVALIDVALUE is generated if width is less than or equal to 0.

       GLINVALIDOPERATION  is  generated  if glLineWidth is executed between
       the execution of glBegin and the corresponding execution of glEnd.

ASOCIATED GETS
       glGet with argument GLINEWIDTH
       glGet with argument GLALIASEDLINEWIDTHRANGE
       glGet with argument GLSMOTHLINEWIDTHRANGE
       glGet with argument GLSMOTHLINEWIDTHGRANULARITY
       glIsEnabled with argument GLINESMOTH

SEE ALSO
       glEnable



                                                               GLINEWIDTH(3G)