glPolygonMode(3G)glPolygonMode(3G)NAMEglPolygonMode - select a polygon rasterization mode
SYNOPSIS
void glPolygonMode(
GLenum face,
GLenum mode );
PARAMETERS
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. 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.
DESCRIPTIONglPolygonMode() controls the interpretation of polygons for rasteriza‐
tion. 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 rasteriza‐
tion 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: 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. 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. The interior of the polygon is filled. Polygon attributes
such as GL_POLYGON_STIPPLE and GL_POLYGON_SMOOTH control the rasteriza‐
tion of the polygon.
NOTES
Vertices are marked as boundary or nonboundary with an edge option.
Edge options 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 GETSglGet() with argument GL_POLYGON_MODE
EXAMPLES
To draw a surface with filled back-facing polygons and outlined front-
facing polygons, call glPolygonMode(GL_FRONT, GL_LINE);
SEE ALSOglBegin(3), glEdgeFlag(3), glLineStipple(3), glLineWidth(3), glPoint‐
Size(3), glPolygonStipple(3)glPolygonMode(3G)