func StencilOp(fail uint32, zfail uint32, zpass uint32) {
	C.glowStencilOp(gpStencilOp, (C.GLenum)(fail), (C.GLenum)(zfail), (C.GLenum)(zpass))
}
func StencilOp(fail uint32, zfail uint32, zpass uint32) {
	C.glowStencilOp(gpStencilOp, (C.GLenum)(fail), (C.GLenum)(zfail), (C.GLenum)(zpass))
}
// set front and back stencil test actions