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GLLINEWIDTH(3G)                                                                              GLLINEWIDTH(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 argument GL_LINE_SMOOTH. Line antialias-ing antialiasing
       ing 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 rasterized, 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 inter-sects intersects
       sects 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 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 difference 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 specified value.

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

ERRORS
       GL_INVALID_VALUE is generated if width is less than or equal to 0.

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

ASSOCIATED GETS
       glGet with argument GL_LINE_WIDTH
       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(3G)




                                                                                             GLLINEWIDTH(3G)