OpenGL extension EXT.cull_vertex
This module customises the behaviour of the OpenGL.raw.GL.EXT.cull_vertex to provide a more Python-friendly API
Overview (from the spec)
This extension introduces a method for culling vertexes in object space based on the value of the dot product between the normal at the vertex and a culling eye direction.
Culling a polygon by examining its vertexes in object space can be more efficient than screen space polygon culling since the transformation to screen space (which may include a division by w) can be avoided for culled vertexes. Also, vertex culling can be computed before vertexes are assembled into primitives. This is a useful property when drawing meshes with shared vertexes, since a vertex can be culled once, and the resulting state can be used for all primitives which share the vertex.
The official definition of this extension is available here: