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<STRONG>NAME</STRONG>
<STRONG>glPolygonMode</STRONG> - select a polygon rasterization mode
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glPolygonMode</STRONG>( GLenum <EM>face</EM>,
GLenum <EM>mode</EM> )
<STRONG>PARAMETERS</STRONG>
<EM>face</EM> Specifies the polygons that <EM>mode</EM> applies to. Must be
<STRONG>GL_FRONT</STRONG> for front-facing polygons, <STRONG>GL_BACK</STRONG> for back-
facing polygons, or <STRONG>GL_FRONT_AND_BACK</STRONG> for front- and
back-facing polygons.
<EM>mode</EM> Specifies how polygons will be rasterized. Accepted
values are <STRONG>GL_POINT</STRONG>, <STRONG>GL_LINE</STRONG>, and <STRONG>GL_FILL</STRONG>. The
initial value is <STRONG>GL_FILL</STRONG> for both front- and back-
facing polygons.
<STRONG>DESCRIPTION</STRONG>
<STRONG>glPolygonMode</STRONG> controls the interpretation of polygons for
rasterization. <EM>face</EM> describes which polygons <EM>mode</EM> applies
to: front-facing polygons (<STRONG>GL_FRONT</STRONG>), back-facing polygons
(<STRONG>GL_BACK</STRONG>), or both (<STRONG>GL_FRONT_AND_BACK</STRONG>). 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 <EM>mode</EM>:
<STRONG>GL_POINT</STRONG> Polygon vertices that are marked as the start
of a boundary edge are drawn as points. Point
attributes such as <STRONG>GL_POINT_SIZE</STRONG> and
<STRONG>GL_POINT_SMOOTH</STRONG> control the rasterization of
the points. Polygon rasterization attributes
other than <STRONG>GL_POLYGON_MODE</STRONG> have no effect.
<STRONG>GL_LINE</STRONG> 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 <STRONG>glLineStipple</STRONG>). Line
attributes such as <STRONG>GL_LINE_WIDTH</STRONG> and
<STRONG>GL_LINE_SMOOTH</STRONG> control the rasterization of
the lines. Polygon rasterization attributes
other than <STRONG>GL_POLYGON_MODE</STRONG> have no effect.
<STRONG>GL_FILL</STRONG> The interior of the polygon is filled.
Polygon attributes such as <STRONG>GL_POLYGON_STIPPLE</STRONG>
and <STRONG>GL_POLYGON_SMOOTH</STRONG> control the
rasterization of the polygon.
<STRONG>EXAMPLES</STRONG>
To draw a surface with filled back-facing polygons and
outlined front-facing polygons, call glPolygonMode(<STRONG>GL_FRONT</STRONG>,
<STRONG>GL_LINE</STRONG>);
<STRONG>NOTES</STRONG>
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
<STRONG>glEdgeFlag</STRONG>.
<STRONG>ERRORS</STRONG>
<STRONG>GL_INVALID_ENUM</STRONG> is generated if either <EM>face</EM> or <EM>mode</EM> is not
an accepted value.
<STRONG>GL_INVALID_OPERATION</STRONG> is generated if <STRONG>glPolygonMode</STRONG> is
executed between the execution of <STRONG>glBegin</STRONG> and the
corresponding execution of <STRONG>glEnd</STRONG>.
<STRONG>ASSOCIATED</STRONG> <STRONG>GETS</STRONG>
<STRONG>glGet</STRONG> with argument <STRONG>GL_POLYGON_MODE</STRONG>
<STRONG>SEE</STRONG> <STRONG>ALSO</STRONG>
<STRONG>glBegin</STRONG>, <STRONG>glEdgeFlag</STRONG>, <STRONG>glLineStipple</STRONG>, <STRONG>glLineWidth</STRONG>,
<STRONG>glPointSize</STRONG>, <STRONG>glPolygonStipple</STRONG>
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