glFrontFace — define front- and back-facing polygons
| ||GLenum mode |
Specifies the orientation of front-facing polygons.
GL_CCW are accepted. The initial value is
In a scene composed entirely of opaque closed surfaces, back-facing polygons are never visible. Eliminating these invisible polygons has the obvious benefit of speeding up the rendering of the image. To enable and disable elimination of back-facing polygons, call glEnable and glDisable with argument
The projection of a polygon to window coordinates is said to have clockwise winding if an imaginary object following the path from its first vertex, its second vertex, and so on, to its last vertex, and finally back to its first vertex, moves in a clockwise direction about the interior of the polygon. The polygon's winding is said to be counterclockwise if the imaginary object following the same path moves in a counterclockwise direction about the interior of the polygon.
glFrontFace specifies whether polygons with clockwise winding in window coordinates, or counterclockwise winding in window coordinates, are taken to be front-facing. Passing
mode selects counterclockwise polygons as front-facing;
GL_CW selects clockwise polygons as front-facing. By default, counterclockwise polygons are taken to be front-facing.
GL_INVALID_ENUM is generated if
mode is not an accepted value.
glGet with argument
|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|
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