纯AS实现水平移动的幻影

var speed:Number = 10;// 粒子速度
var shadow_arr:Array = new Array();// 粒子数组
var shadow_num:Number = 10;// 影子数量
var shadow_step:Number = 2;// 影子步长
var shadow_scale:Number = 40;// 影子缩放比例
var id:Number = 0;
//////////////////////////////////////////////////
//             绘制主体                                                                                                 //
/////////////////////////////////////////////////
var body = _root.createEmptyMovieClip("body", 0);
shadow_arr.push(body);
function drawBody():Void {
   body._x = 0;
   body._y = Stage.height/2;
   body.lineStyle(5, 0xffffff, 100);
   body.moveTo(0, 0);
   body.lineTo(-5, 0);
}
drawBody();
///////////////////////////////////////////////
//    使移动
body.onEnterFrame = function() {
   this._x += speed;
   if (isOut(this)) {             //是否出台
      this._x = 0;
   }
   updateAfterEvent();
};
function isOut(b:MovieClip):Boolean {
   return (b._x>Stage.width);
}
function copyBody() {
   var cBody = body.duplicateMovieClip("body" add id, id+10);
   shadow_arr.push(cBody);
   cBody._x = shadow_arr[id]._x-shadow_step;    // 比前一个影子的坐标少步长大小
   cBody.onEnterFrame = body.onEnterFrame;    // 按body的规律运动
   id++;
   shadow_arr[id]._alpha -= (80/shadow_num)*id;
   
   shadow_arr[id]._yscale -= (shadow_scale/shadow_num)*id;
   if (id == shadow_num) {          // 复制出足够的影子了
      clearInterval(copyShadowid);
   }
}
var copyShadowid = setInterval(copyBody, speed);