円をvx,vyで動かす

/**
 * Copyright hacker_szoe51ih ( http://wonderfl.net/user/hacker_szoe51ih )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/46lr
 */

// forked from hacker_szoe51ih's forked from: forked from: flash on 2010-5-2
// forked from hacker_szoe51ih's forked from: flash on 2010-5-2
// forked from hacker_szoe51ih's flash on 2010-5-2
package {
    import flash.display.*;
    import flash.events.*;
    
    [SWF(backgroundColor="#ffffff", width="465", height="465", frameRate="30")]
    
    public class MyFirstAnimation extends Sprite {
    	
    	private var _circle:Circle;
    	
    	public function MyFirstAnimation(){
    		_circle= new Circle(30,0xdd3366);
    		_circle.alpha=1;
    		
    		//移動スピードを設定
    		_circle.vx=4;
    		_circle.vy=2;
    		
    		//最初の表示位置を設定
    		_circle.x=465/2;
    		_circle.y=465/2;
    		
    		addChild(_circle);
    		
    		addEventListener(Event.EXIT_FRAME,enterFrameHandler);
    	}
    	
    	private function enterFrameHandler(e:Event):void{
    		_circle.move();
    	}

        
    }
}

//円を描画するクラス
import flash.display.Sprite;
import flash.display.Sprite;
import flash.ui.ContextMenuItem;

class Circle extends Sprite{
	
	public var vx:Number;
	public var vy:Number;
	public var radius:Number;
	
	public function Circle(_radius:Number,_fillColor:uint=0x000000){
		graphics.beginFill(_fillColor);
		graphics.drawCircle(0,0,_radius);
		graphics.endFill();
		radius=_radius;
	}
	
	public function move():void{
		x+=vx;
		y+=vy;
	}
}