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.
To draw a surface with outlined polygons, call
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
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.
GL_INVALID_ENUM is generated if either face or mode is not an accepted value.
glGet with argument GL_POLYGON_MODE
| OpenGL Version | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Function / Feature Name | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5 |
glPolygonMode | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
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