GL_SGIS_detail_texture
http://www.opengl.org/registry/specs/SGIS/detail_texture.txt
GL_SGIS_detail_texture
	void glDetailTexFuncSGIS (GLenum target, GLsizei n, const GLfloat* points)
	void glGetDetailTexFuncSGIS (GLenum target, GLfloat* points)
