func GetClipPlane(plane uint32, equation *float64) {
	C.glowGetClipPlane(gpGetClipPlane, (C.GLenum)(plane), (*C.GLdouble)(unsafe.Pointer(equation)))
}
func GetClipPlane(plane uint32, equation *float64) {
	C.glowGetClipPlane(gpGetClipPlane, (C.GLenum)(plane), (*C.GLdouble)(unsafe.Pointer(equation)))
}
// return the coefficients of the specified clipping plane