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 FleeEvadeWanderTest extends Sprite {
 
        private var _pursuer:SteeredVehicle;
        private var _evader:SteeredVehicle;
        private var _target:SteeredVehicle;
        private var _seeker:SteeredVehicle;
        private var _fleer:SteeredVehicle;      
        private var _text:TextField;
        private var _isRun:Boolean = false;
 
        public function FleeEvadeWanderTest() {
            stage.align=StageAlign.TOP_LEFT;
            stage.scaleMode=StageScaleMode.NO_SCALE;            
 
            _evader=new SteeredVehicle(0x00ff00);//躲避者(绿色)          
            addChild(_evader);
             
            _target=new SteeredVehicle(0x000000);//目标(黑色)           
            _target.velocity.length = 20;
            addChild(_target);      
 
            _fleer=new SteeredVehicle(0xffff00);//避开者(黄色)           
            addChild(_fleer);
 
            _target.edgeBehavior =  _evader.edgeBehavior =  _fleer.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(50,50);
                _evader.position = _fleer.position=new Vector2D(stage.stageWidth/2,stage.stageHeight/2);                
                addEventListener(Event.ENTER_FRAME, onEnterFrame);
                _isRun=true;
                removeChild(_text);
            } else {
                _evader.position = _target.position=_fleer.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 {
            _target.wander();           
            _fleer.flee(_target.position);          
            _evader.evade(_target);
            _target.update();           
            _fleer.update();
            _evader.update();
 
             
        }
    }
}