GL_NV_geometry_program4 http://developer.download.nvidia.com/opengl/specs/GL_NV_geometry_program4.txt GL_NV_gpu_program4 GL_GEOMETRY_PROGRAM_NV 0x8C26 GL_MAX_PROGRAM_OUTPUT_VERTICES_NV 0x8C27 GL_MAX_PROGRAM_TOTAL_OUTPUT_COMPONENTS_NV 0x8C28 void glProgramVertexLimitNV (GLenum target, GLint limit)