- select a polygon rasterization mode



C SPECIFICATION


PARAMETERS

       _param1  Specifies  the  polygons that _param2 applies to.
                Must  be  GL_FRONT  for  front-facing   polygons,
                GL_BACK     for    back-facing    polygons,    or
                GL_FRONT_AND_BACK  for  front-  and   back-facing
                polygons.

       _param2  Specifies   how   polygons  will  be  rasterized.
                Accepted  values  are  GL_POINT,   GL_LINE,   and
                GL_FILL.   The  initial value is GL_FILL for both
                front- and back-facing polygons.


DESCRIPTION

       glPolygonMode controls the interpretation of polygons  for
       rasterization.   _param1  describes which polygons _param2
       applies to: front-facing polygons (GL_FRONT),  back-facing
       polygons  (GL_BACK),  or  both  (GL_FRONT_AND_BACK).   The
       polygon mode affects only the final rasterization of poly-
       gons.  In particular, a polygon's vertices are lit and the
       polygon is clipped and possibly culled before these  modes
       are applied.

       Three modes are defined and can be specified in _param2:

       GL_POINT      Polygon  vertices  that  are  marked  as the
                     start  of  a  boundary  edge  are  drawn  as
                     points.     Point    attributes    such   as
                     GL_POINT_SIZE  and  GL_POINT_SMOOTH  control
                     the  rasterization  of  the points.  Polygon
                     rasterization    attributes    other    than
                     GL_POLYGON_MODE have no effect.

       GL_LINE       Boundary  edges  of the polygon are drawn as
                     line segments.  They  are  treated  as  con-
                     nected line segments for line stippling; the
                     line stipple counter  and  pattern  are  not
                     reset  between segments (see glLineStipple).
                     Line attributes such  as  GL_LINE_WIDTH  and
                     GL_LINE_SMOOTH  control the rasterization of
                     the lines.  Polygon rasterization attributes
                     other than GL_POLYGON_MODE have no effect.

       GL_FILL       The  interior  of  the  polygon  is  filled.
                     Polygon       attributes       such       as
                     GL_POLYGON_STIPPLE   and   GL_POLYGON_SMOOTH
                     control the rasterization of the polygon.


EXAMPLES

       GL_INVALID_OPERATION is generated if glPolygonMode is exe-
       cuted between the execution of glBegin and the correspond-
       ing execution of glEnd.


ASSOCIATED GETS

       glGet with argument GL_POLYGON_MODE


SEE ALSO

       glBegin,    glEdgeFlag,    glLineStipple,     glLineWidth,
       glPointSize, glPolygonStipple



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