func StencilOpSeparate(face uint32, sfail uint32, dpfail uint32, dppass uint32) {
	syscall.Syscall6(gpStencilOpSeparate, 4, uintptr(face), uintptr(sfail), uintptr(dpfail), uintptr(dppass), 0, 0)
}
func StencilOpSeparate(face uint32, sfail uint32, dpfail uint32, dppass uint32) {
	syscall.Syscall6(gpStencilOpSeparate, 4, uintptr(face), uintptr(sfail), uintptr(dpfail), uintptr(dppass), 0, 0)
}
// set front and/or back stencil test actions