func BindTextureUnit(unit uint32, texture uint32) {
	syscall.Syscall(gpBindTextureUnit, 2, uintptr(unit), uintptr(texture), 0)
}
func BindTextureUnit(unit uint32, texture uint32) {
	syscall.Syscall(gpBindTextureUnit, 2, uintptr(unit), uintptr(texture), 0)
}
// bind an existing texture object to the specified texture unit