Acceleration

by crossisland 07 Nov 2011

Embed

/**
 * Copyright crossisland ( http://wonderfl.net/user/crossisland )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/9RNd
 */

package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    import flash.ui.Keyboard;
    
    public class Acceleration extends Sprite {
        private var ball:Ball;
        private var vx:Number = 0;
        private var vy:Number = 0;
        private var ax:Number = 0;
        private var ay:Number = 0;
        
        public function Acceleration() {
            init();
        }
        
        private function init():void {
            ball = new Ball();
            addChild(ball);
            ball.x = 50;
            ball.y = 100;
            addEventListener(Event.ENTER_FRAME, onEnterFrame);
            stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
            stage.addEventListener(KeyboardEvent.KEY_UP, onKeyUp);
        }
        
        private function onKeyDown(event:KeyboardEvent):void {
            switch (event.keyCode) {
                case Keyboard.LEFT:
                    ax = -0.2;
                    break;
                case Keyboard.RIGHT:
                    ax = 0.2;
                    break;
                case Keyboard.UP:
                    ay = -0.2;
                    break;
                case Keyboard.DOWN:
                    ay = 0.2;
                    break;
                default:
                    break;
            }
        }
        
        private function onKeyUp(event:KeyboardEvent):void {
            ax = 0;
            ay = 0;
        }
        
        private function onEnterFrame(event:Event):void {
            vx += ax;
            vy += ay;
            ball.x += vx;
            ball.y += vy;
        }
    }
}

import flash.display.Sprite;

class Ball extends Sprite {
    public var radius:Number;
    private var color:uint;
    
    public function Ball(radius:Number=40, color:uint=0x000000) {
        this.radius = radius;
        this.color = color;
        init();
    }
    
    public function init():void {
        graphics.beginFill(color);
        graphics.drawCircle(0, 0, radius);
        graphics.endFill();
    }
}