- 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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