inpututil/inpututil.go
func TouchPressDuration(id int) int {
	theInputState.m.RLock()
	s := theInputState.touchDurations[id]
	theInputState.m.RUnlock()
	return s
}
func TouchPressDuration(id int) int {
	theInputState.m.RLock()
	s := theInputState.touchDurations[id]
	theInputState.m.RUnlock()
	return s
}
// TouchPressDuration returns how long the touch remains in frames.
//
// TouchPressDuration is concurrent safe.