manewcActionscript Snippets

APE Vectors, Built-In Collision Detection, User Control

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This movie demonstrates the ability to move one object that collides with another object. You have control over the white ball by simply using your arrow keys. I modified the classes slightly and added some more configuration to the circle classes.

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import org.cove.ape.APEngine;
	import org.cove.ape.Vector;
	import org.cove.ape.CircleParticle;
	import org.cove.ape.Group;
	import flash.events.KeyboardEvent;
	import flash.ui.Keyboard;
	import flash.text.TextField;

	public class Main extends Sprite
	{
		private	var cp:Circle = new Circle( stage.stageWidth / 2, stage.stageHeight / 2, 30 );
		private var walls:Walls = new Walls( stage.stageWidth, stage.stageHeight );
		private var ball:Circle = new Circle( stage.stageWidth / 2, stage.stageHeight / 2, 50, 0xb84777 );

		public function Main()
		{
			APEngine.init(1/4);

			// set up the default diplay container
			APEngine.container = this;
			APEngine.addMasslessForce(new Vector(0,0));

			APEngine.addGroup(cp);
			APEngine.addGroup(ball);
			APEngine.addGroup(walls);

			cp.addCollidable ( ball );
			cp.addCollidable ( walls );
			ball.addCollidable ( walls );

			// make the ball move
			ball.cp.velocity = (new Vector(Math.random() * 5, Math.random() * 5));

			stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownHandler);
            addEventListener(Event.ENTER_FRAME, run);
		}

		private function run(e:Event):void
		{
			APEngine.step();
			APEngine.paint();
		}

		private function keyDownHandler(k:KeyboardEvent):void
		{
			if (k.keyCode == Keyboard.UP) {
				cp.cp.velocity = (new Vector(0, -10));
			} else if (k.keyCode == Keyboard.DOWN) {
				cp.cp.velocity = (new Vector(0, 10));
			} else if (k.keyCode == Keyboard.RIGHT) {
				cp.cp.velocity = (new Vector(10, 0));
			} else if (k.keyCode == Keyboard.LEFT) {
				cp.cp.velocity = (new Vector(-10, 0));
			}
		}
	}
}

The Walls class

package
{
	import org.cove.ape.Group;
	import org.cove.ape.RectangleParticle;  

	public class Walls extends Group
	{

		public function Walls(bw:Number, bh:Number)
		{
			// top
			var t:RectangleParticle = new RectangleParticle(bw/2, -50, bw, 100, 0, true);
			addParticle(t);

			// this is the bottom
			var b:RectangleParticle = new RectangleParticle(bw/2, bh + 50, bw, 100, 0, true);
			addParticle(b);

			// left
			var l:RectangleParticle = new RectangleParticle(-50, bh / 2, 100, bh, 0, true);
			addParticle(l);  

			// right
			var r:RectangleParticle = new RectangleParticle(bw + 50, bh / 2, 100, bh, 0, true);
			addParticle(r);
		}
	}
}

The Circle Class

package
{
	import org.cove.ape.Group;
	import org.cove.ape.CircleParticle;
	import org.cove.ape.Vector;

	public class Circle extends Group
	{
		public var cp:CircleParticle;

		public function Circle(x:uint, y:uint, r:Number=5, c:uint = 0xffffff)
		{
			cp = new CircleParticle(x, y, r, false, 3, .8);
			cp.setStyle(0, 0, 0, c);
			addParticle(cp);
		}
	}
}

Wednesday, August 20th, 2008 at 9:24 am and is filed under APE - Actionscript Physics Engine, Actionscript 3. 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.