_glCullFace: specify whether front- or back-facing facets can be culled
- SUB _glCullFace (BYVAL mode AS _UNSIGNED LONG)
- void _glCullFace(GLenum mode);
- Specifies whether front- or back-facing facets are candidates for culling. Symbolic constants _GL_FRONT, _GL_BACK, and _GL_FRONT_AND_BACK are accepted. The initial value is _GL_BACK.
_glCullFace specifies whether front- or back-facing facets are culled (as specified by mode) when facet culling is enabled. Facet culling is initially disabled. To enable and disable facet culling, call the _glEnable and _glDisable commands with the argument _GL_CULL_FACE. Facets include triangles, quadrilaterals, polygons, and rectangles.
If mode is _GL_FRONT_AND_BACK, no facets are drawn, but other primitives such as points and lines are drawn.
_GL_INVALID_ENUM is generated if mode is not an accepted value.