glPolygonMode — select a polygon rasterization mode
void glPolygonMode( | GLenum face, |
GLenum mode) ; |
face
Specifies the polygons that mode
applies to.
Must be 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.
glPolygonMode
controls the interpretation of polygons for rasterization.
face
describes which polygons mode
applies to:
both front and back-facing polygons (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.
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_SMOOTH
control the rasterization of the polygon.
Vertices are marked as boundary or nonboundary with an edge flag. Edge flags are generated internally by the GL when it decomposes triangle stips and fans.
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