複数のインスタンスに同時に、絵を描くアプリ

複数のインスタンスに、同時に絵を描くアプリを作りたいおですが、どこがおかしいのか、わからないまま、つまずいてしまっています。どなたか、回答を、お願いします。

package {

import flash.display.Graphics;
import flash.display.Sprite;
import flash.display.Shape;
import flash.events.MouseEvent;
import flash.events.Event;
import flash.geom.Point;

public class draw_lines_001 extends Sprite {
    
    private static const INIT_SEGMENTS:uint=10;
    private static const THICKNESS:uint=5;
    private static const COLOR:uint=0xffcccc;
    private static const ALPHA:Number=0.1;
    private static const ROTATION_RATE:uint=1;
    private var _shapeHolder:Sprite;
    private var _shapes:Vector.<Shape>;
    
    public function draw_lines_001():void {
        init();
    }
    
    public function init():void{
        _shapeHolder=new Sprite();
        _shapeHolder.x=50;
        _shapeHolder.y=50;
        addChild(_shapeHolder);
        for(var i:uint=0;i<INIT_SEGMENTS;i++){
            addSegment();
        }
        positionSegments();
        stage.addEventListener(MouseEvent.MOUSE_DOWN,mouse_down);
        stage.addEventListener(MouseEvent.MOUSE_UP,mouse_up);
    }
    
    private function addSegment():void{
        var shape:Shape=new Shape();
        if(_shapes.length>0){
            shape.graphics.copyFrom(_shapes[0].graphics);
        }else{
            shape.graphics.lineStyle(THICKNESS,COLOR,ALPHA);
        }
        _shapes.push(shape);
        _shapeHolder.addChild(shape);
    }

// private function remooveSegment():void{
// var shape:Shape=_shapes.pop();
// _shapeHolder.removeChild(shape);
// }

    private function positionSegments():void{
        var segments:uint=_shapeHolder.numChildren;
        var angle:Number=360/segments;
        for(var i:uint=1;i<segments;i++){
            _shapes[i].rotation=angle*i;
        }
    }
    
    private function mouse_down(event:MouseEvent):void{
        var shape:Shape=_shapes[0];
        shape.graphics.moveTo(shape.mouseX,shape.mouseY);
        addEventListener(Event.ENTER_FRAME,onThisEnterFrame);
    }
    
    private function mouse_up(event:MouseEvent):void{
        removeEventListener(Event.ENTER_FRAME,onThisEnterFrame);
    }
    
    private function onThisEnterFrame(event:Event):void{
        _shapeHolder.rotation+=ROTATION_RATE;
        draw();
    }

    private function draw():void{
        var shape:Shape=_shapes[0];
        shape.graphics.lineTo(shape.mouseX,shape.mouseY);
        var segments:uint=_shapeHolder.numChildren;
        for(var i:uint=1;i<segments;i++){
            _shapes[i].graphics.copyFrom(shape.graphics);
        }

    }
    
}

}