OpenGL extension EXT.polygon_offset
This module customises the behaviour of the OpenGL.raw.GL.EXT.polygon_offset to provide a more Python-friendly API
Overview (from the spec)
The depth values of fragments generated by rendering polygons are displaced by an amount that is proportional to the maximum absolute value of the depth slope of the polygon, measured and applied in window coordinates. This displacement allows lines (or points) and polygons in the same plane to be rendered without interaction -- the lines rendered either completely in front of or behind the polygons (depending on the sign of the offset factor). It also allows multiple coplanar polygons to be rendered without interaction, if different offset factors are used for each polygon. Applications include rendering hidden-line images, rendering solids with highlighted edges, and applying `decals' to surfaces.
The official definition of this extension is available here: