GL_EXT_polygon_offset http://www.opengl.org/registry/specs/EXT/polygon_offset.txt GL_EXT_polygon_offset GL_POLYGON_OFFSET_EXT 0x8037 GL_POLYGON_OFFSET_FACTOR_EXT 0x8038 GL_POLYGON_OFFSET_BIAS_EXT 0x8039 void glPolygonOffsetEXT (GLfloat factor, GLfloat bias)