func (u *UserInterface) currentMonitor() *glfw.Monitor {
	w := u.window
	if m := w.GetMonitor(); m != nil {
		return m
	}
	// Get the monitor which the current window belongs to. This requires OS API.
	return u.currentMonitorFromPosition()
}
func (u *UserInterface) currentMonitor() *glfw.Monitor {
	w := u.window
	if m := w.GetMonitor(); m != nil {
		return m
	}
	// Get the monitor which the current window belongs to. This requires OS API.
	return u.currentMonitorFromPosition()
}
// currentMonitor returns the monitor most suitable with the current window.
//
// currentMonitor must be called on the main thread.