AS本をベースに練習中

れんしゅう

addChild(new Stats());

public class ShipSim extends Sprite{
private var ship:Ship;
private var vr:Number = 0;
private var thrust:Number =0;
private var vx:Number = 0;
private var vy:Number = 0;
public function ShipSim(){
init();
}

public function init():void{
graphics.beginFill(0);
graphics.drawRect(0,0,stage.stageWidth,stage.stageHeight);
graphics.endFill();
ship = new Ship();
addChild(ship);
ship.x = stage.stageWidth / 2;
ship.y = stage.stageHeight / 2;
addEventListener(Event.ENTER_FRAME, onEnterFrame);
stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
stage.addEventListener(KeyboardEvent.KEY_UP, onKeyUp);
}
private function onKeyDown(e:KeyboardEvent):void{
switch(e.keyCode){
case Keyboard.LEFT:
vr = -5;
break;

case Keyboard.RIGHT:
vr = 5;
break;

case Keyboard.UP:
thrust =0.2;
ship.draw(true);
break;

default:
break;
}

}
private function onKeyUp(e:KeyboardEvent):void{
vr = 0;
thrust =0;
ship.draw(false);
}
private function onEnterFrame(e:Event):void{
ship.rotatio