[Flash 11]

Novembre 2012

A simple test to create a multitouch joystick for Starling.
It’s not easy to test on a regular desktop ^^
But you you can move the knob with your mouse and use your keyboard.
Key SPACE to open fire
Key A to realease a trail of stars

Download the Android test-joystick.apk

*** update
Converted my jpg background (500Ko) to ATF (71ko) texture !
And added an infinite scrolling background :)

Creating the ATF texture

var ba:ByteArray = new starfieldClass();
var texture:Texture = Texture.fromAtfData(ba as ByteArray);
texture.repeat = true;
starfield = new Image(texture);
addChild( starfield );

How to convert texture to ATF

adding an infinite scrolling

if (!joy.NONE)
{				
	var p:Point;
	for (var i:int = 0; i < 4; i++)
	{
		p = starfield.getTexCoords(i);
		p.x += (v * Math.cos(joy.angle) * .001);
		p.y += (v * Math.sin(joy.angle) * .001);
		starfield.setTexCoords(i, p);
	}			
}
&#91;/as3&#93;

<br />
<p>And the source code of my virtualjoystick</p>
[as3]
package
{
	import starling.display.Image;
	import starling.display.Sprite;
	import starling.events.Event;
	import starling.events.Touch;
	import starling.events.TouchEvent;
	import starling.events.TouchPhase;
	import starling.textures.Texture;

	public class VirtualJoystick extends Sprite
	{
		// -- conf
		private var DISTANCE_MIN:int = 50;
		private var DISTANCE_MAX:int = 100;		
		
		// -- DIRS
		public var UP:Boolean 	= false;
		public var DW:Boolean 	= false;
		public var LF:Boolean 	= false;
		public var RG:Boolean 	= false;
		public var NONE:Boolean = true;		
		
		public var speed_factor:Number	= .0;
		public var angle:Number	= .0;
		
		// --
		private var _knobX:int = 0;
		private var _knobY:int = 0;
		
		// --
		private var _knob:Image;
		private var _joystick:Image;
		
		public function VirtualJoystick(x:int, y:int, scale:Number = 1) {
			this.x = x;
			this.y = y;
			this.scaleX = this.scaleY =  scale;
			addEventListener(Event.ADDED_TO_STAGE, _onAddedToStage );			
		}
		
		private function _onAddedToStage(event:Event):void
		{
			removeEventListener(Event.ADDED_TO_STAGE, _onAddedToStage );	

			/*
                        var joy:Shape = new Shape();
			joy.graphics.beginFill(0x333333);
			joy.graphics.drawRect(0, 0, 150, 150);
			joy.graphics.endFill();
			var dat:BitmapData = new BitmapData(150, 150, true, 0x0);
			dat.draw( joy );
			
			var knob:Shape = new Shape();
			knob.graphics.beginFill(0xCC0000);
			knob.graphics.drawCircle(40,40,40)
			knob.graphics.endFill();
			var dat2:BitmapData = new BitmapData(80, 80, true, 0x0);
			dat2.draw(knob);
			*/

			_joystick = new Image( Texture.fromBitmapData( new Border ) ); // dat
			_joystick.pivotX = _joystick.width >> 1;
			_joystick.pivotY = _joystick.height >> 1;
			_joystick.addEventListener(TouchEvent.TOUCH, _onTouch);
			addChild( _joystick );
			
			_knob = new Image( Texture.fromBitmapData( new Knob ) ); // dat2
			_knob.pivotX = _knob.width >> 1;
			_knob.pivotY = _knob.height >> 1;
			_knob.touchable = false;
			addChild( _knob );
		}
		
		private function _onTouch(e:TouchEvent):void
		{
			e.stopImmediatePropagation();
			var touch:Touch = e.getTouch(this);
			
			if (touch)
			{
				switch (touch.phase)
				{
					
					case TouchPhase.ENDED: 
						_knobX = 0;
						_knobY = 0;
						LF = false;
						RG = false;
						UP = false;
						DW = false;
						NONE = true;
						_update();
						break;
					
					case TouchPhase.BEGAN: 
					case TouchPhase.MOVED: 
						NONE = false;
						_onTouchMove(touch);
						break;
					
					default: 
					// --
				}
				
			}
		}		
		
		private function _onTouchMove(touch:Touch):void
		{
			var dx:int = (touch.globalX / SB.ratioX - x); // default SB.ratioX = 1
			var dy:int = (touch.globalY / SB.ratioY - y); // default SB.ratioY = 1
			angle = Math.atan2(dy, dx);
			var dist:int = Math.sqrt(dx * dx + dy * dy);			
			if (dist < DISTANCE_MAX) {
				_knobX = dx;
				_knobY = dy;
			} else {
				_knobX = (Math.cos(angle) * DISTANCE_MAX);
				_knobY = (Math.sin(angle) * DISTANCE_MAX);
				dist = DISTANCE_MAX;
			}
			// --
			LF = (dx < -DISTANCE_MIN);
			RG = (dx > DISTANCE_MIN);
			UP = (dy < -DISTANCE_MIN);
			DW = (dy > DISTANCE_MIN);		
			// --
			speed_factor = dist / DISTANCE_MAX;
                        _update();
		}		
		
		private function _update():void
		{
			if(this.stage != null){
				_knob.x = _knobX;
				_knob.y = _knobY;
			}
		}			


		// ================================================================
		
		public function destroy():void
		{
			_joystick.removeEventListener(TouchEvent.TOUCH, _onTouch);
			removeChildren();
		}
	}
}