internal/uidriver/glfw/ui.go
func (u *UserInterface) actualScreenScale() float64 {
	// Avoid calling monitor.GetPos if we have the monitor position cached already.
	if cm, ok := getCachedMonitor(u.window.GetPos()); ok {
		return u.getScale() * devicescale.GetAt(cm.x, cm.y)
	}
	return u.getScale() * devicescale.GetAt(u.currentMonitor().GetPos())
}
func (u *UserInterface) actualScreenScale() float64 {
	// Avoid calling monitor.GetPos if we have the monitor position cached already.
	if cm, ok := getCachedMonitor(u.window.GetPos()); ok {
		return u.getScale() * devicescale.GetAt(cm.x, cm.y)
	}
	return u.getScale() * devicescale.GetAt(u.currentMonitor().GetPos())
}
// actualScreenScale must be called from the main thread.