package {
 
    import flash.display.Sprite;
    import flash.display.StageAlign;
    import flash.display.StageScaleMode;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.text.TextField;
     
    public class PursueEvadeTest extends Sprite {
 
        private var _pursuer:SteeredVehicle;
        private var _evader:SteeredVehicle;
        private var _target:SteeredVehicle;
        private var _seeker:SteeredVehicle;
        private var _fleer:SteeredVehicle;
        private var _pursuer2:SteeredVehicle;
        private var _evader2:SteeredVehicle;
        private var _text:TextField;
        private var _isRun:Boolean = false;
 
        public function PursueEvadeTest() {
            stage.align=StageAlign.TOP_LEFT;
            stage.scaleMode=StageScaleMode.NO_SCALE;
 
            _pursuer=new SteeredVehicle(0xff0000);
            addChild(_pursuer);
 
            _evader=new SteeredVehicle(0x00ff00);           
            addChild(_evader);
             
            _target=new SteeredVehicle(0x000000);
            _target.velocity.length=15;         
            addChild(_target);
 
            _seeker=new SteeredVehicle(0xff00ff);
            addChild(_seeker);
 
            _fleer=new SteeredVehicle(0xffff00);            
            addChild(_fleer);
 
 
            _pursuer2 = new SteeredVehicle();
            addChild(_pursuer2);
 
            _evader2 = new SteeredVehicle();            
            addChild(_evader2);
 
            _evader2.edgeBehavior = _pursuer2.edgeBehavior = _target.edgeBehavior = _evader.edgeBehavior = _pursuer.edgeBehavior = _fleer.edgeBehavior = _seeker.edgeBehavior = Vehicle.BOUNCE
            ;
            _text = new TextField();
            _text.text="点击鼠标开始演示";
            _text.height=20;
            _text.width=100;
            _text.x=stage.stageWidth/2-_text.width/2;
            _text.y=stage.stageHeight/2-_text.height/2;
            addChild(_text);
            stage.addEventListener(MouseEvent.CLICK,stageClick);
        }
 
 
        private function stageClick(e:MouseEvent):void {
            if (! _isRun) {
                _target.position=new Vector2D(stage.stageWidth/2,stage.stageHeight/2);
                _fleer.position=new Vector2D(400,300);
                _evader2.position=new Vector2D(400,200);
                _evader.position=new Vector2D(400,100);
                addEventListener(Event.ENTER_FRAME, onEnterFrame);
                _isRun=true;
                removeChild(_text);
            } else {
                _pursuer2.position =_evader2.position = _evader.position = _pursuer.position = _target.position=_seeker.position=_pursuer.position= new Vector2D(0,0);
                removeEventListener(Event.ENTER_FRAME, onEnterFrame);
                _isRun=false;               
                addChild(_text);
                _text.text="点击鼠标重新开始";
            }
        }
 
 
        private function onEnterFrame(event:Event):void {
            _seeker.seek(_target.position);
            _fleer.flee(_target.position);
            _pursuer.pursue(_target);
            _evader.evade(_target);
 
            _pursuer2.pursue(_evader2);
            _evader2.evade(_pursuer2);
 
            _target.update();
            _seeker.update();
            _pursuer.update();
            _fleer.update();
            _evader.update();
 
            _pursuer2.update();
            _evader2.update();
        }
    }
}