GL_NV_texture_rectangle
http://oss.sgi.com/projects/ogl-sample/registry/NV/texture_rectangle.txt
	GL_TEXTURE_RECTANGLE_NV 0x84F5
	GL_TEXTURE_BINDING_RECTANGLE_NV 0x84F6
	GL_PROXY_TEXTURE_RECTANGLE_NV 0x84F7
	GL_MAX_RECTANGLE_TEXTURE_SIZE_NV 0x84F8