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GLPOLYGONMODE()                                                GLPOLYGONMODE()


NAME

       glPolygonMode - select a polygon rasterization mode


C SPECIFICATION

       void glPolygonMode( GLenum face,
                           GLenum mode )


PARAMETERS

       face  Specifies the polygons that mode 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.

       mode  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.  face describes which polygons mode 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 polygons.  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 mode:

       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 connected 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

       To draw a surface with filled back-facing polygons and outlined front-
       facing polygons, call glPolygonMode(GL_FRONT, GL_LINE);


NOTES

       Vertices are marked as boundary or nonboundary with an edge flag.  Edge
       flags are generated internally by the GL when it decomposes polygons;
       they can be set explicitly using glEdgeFlag.


ERRORS

       GL_INVALID_ENUM is generated if either face or mode is not an accepted
       value.

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


ASSOCIATED GETS

       glGet with argument GL_POLYGON_MODE


SEE ALSO

       glBegin, glEdgeFlag, glLineStipple, glLineWidth, glPointSize,
       glPolygonStipple

                                                               GLPOLYGONMODE()

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