manewcActionscript Snippets

Trails Animation

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This code was submitted to me via email who requested some assistance to get this trailing animation to be bound by any newly created object. I edited the code slightly and added a Rect class to build my rectangle object (which could be replaced by an image if so desired). I added a timer to reproduce the object, here is the resulting code/movie:

The Main.as:

package
{
	import flash.display.MovieClip;
	import flash.events.Event;
	import flash.utils.Timer;
	import flash.events.TimerEvent;

	 public class Main extends MovieClip
	 {
		private var clip_arr:Array; // an array of clips
		private var clip_ct:Number = 0;

		private var clip_mc:Rect;

		private const RADIUS:int=30;
		private const FRICTION:Number=.95;

		public function Main()
		{
			init();
		}

		private function init():void
		{
			stage.frameRate=31;

			clip_arr = new Array();

			var myTimer:Timer = new Timer(500, 50);
            myTimer.addEventListener("timer", createClip);
            myTimer.start();
		}

		private function createClip(e:TimerEvent):void
		{
			var randXOffset = Math.random() * stage.stageWidth;
			var randYOffset = Math.random() * stage.stageHeight;

			clip_arr.push ( new Rect() );
			clip_arr[clip_ct].x=Math.cos(clip_arr[clip_ct].angle*1)*RADIUS + randXOffset;
			clip_arr[clip_ct].y=Math.sin(clip_arr[clip_ct].angle*2)*RADIUS + randYOffset;
			clip_arr[clip_ct].offsetX = randXOffset;
			clip_arr[clip_ct].offsetY = randYOffset;
			clip_arr[clip_ct].angle=0;
			addChild(clip_arr[clip_ct]);
			clip_arr[clip_ct].addEventListener(Event.ENTER_FRAME,go);

			clip_ct++;
		}

		private function go(evt:Event):void
		{
  			evt.target.x=Math.cos(evt.target.angle*2)*RADIUS + evt.target.offsetX;
  			evt.target.y=Math.sin(evt.target.angle*3)*RADIUS + evt.target.offsetY;
  			evt.target.angle+=.05;

  			var copy_mc:MovieClip=new Rect();
  			addChild(copy_mc);

  			copy_mc.x=evt.target.x;
  			copy_mc.y=evt.target.y;
 			copy_mc.addEventListener(Event.ENTER_FRAME,goCopy);
		}

		private function goCopy(evt:Event):void
		{
			evt.target.alpha*=FRICTION;
			evt.target.scaleY=evt.target.alpha;
			if(evt.target.alpha<=.3)
			{
				evt.target.removeEventListener(Event.ENTER_FRAME,goCopy);
				var m:MovieClip=evt.target as MovieClip;
				removeChild(m);
			}
		}
	}
}

The rect class:

package
{
	import flash.display.MovieClip;

	public class Rect extends MovieClip
	{
		private var xPos:Number;
		private var yPos:Number;
		private var rWidth:Number;
		private var rHeight:Number;
		private var color:uint;

		public var angle = Number;
		public var offsetX = Number;
		public var offsetY = Number;

		public function Rect(xPos:Number=0,yPos:Number=0,rWidth:Number=10,rHeight:Number=10,color:uint=0x336699)
		{
			this.graphics.beginFill(color);
			this.graphics.drawRect(xPos,yPos,rWidth,rHeight);
			this.graphics.endFill();

			this.angle = 0;
		}
	}
}

Thursday, August 21st, 2008 at 8:53 am and is filed under Actionscript 3, Animation Transitions, Arrays. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.