dual.html

<html><body>
<script src="virtualjoystick.js"></script>
<script>
	console.log("touchscreen is", VirtualJoystick.touchScreenAvailable() ? "available" : "not available");

	// 
	var joystick	= new VirtualJoystick({
		container	: document.body,
		strokeStyle	: 'cyan'
	});
	joystick.addEventListener('touchStartValidation', function(event){
		var touch	= event.changedTouches[0];
		if( touch.pageX < window.innerWidth/2 )	return false;
		return true
	});

	// one on the right of the screen
	var joystick	= new VirtualJoystick({
		container	: document.body,
		strokeStyle	: 'orange'
	});
	joystick.addEventListener('touchStartValidation', function(event){
		var touch	= event.changedTouches[0];
		if( touch.pageX >= window.innerWidth/2 )	return false;
		return true
	});
</script></body>
</html>