创建粒子拖尾效果

import flash.events.Event;
import flash.filters.BlurFilter;
import flash.filters.GlowFilter;
import crawlingtosea.utils.MathUtil;
import flash.display.Shape;
//@author mengtianwxs
var arr:Array = [];
var angle:Number = 0;
var radius:Number = 150;
var len:int = 0;
function p(radius:int,color:uint):Shape
{
  var c:Shape=new Shape();
  c.graphics.beginFill(color);
  c.graphics.drawCircle(0,0,radius);
  c.graphics.endFill();
  return c;
}

for (var i:uint=0; i<60; i++)
{

  this["p" + i] = p(2,0xff0000);
  this.addChild(this["p"+i]);
  arr.push(this["p"+i]);

}
len = arr.length - 1;

for (var j:int=0; j<len; j++)
{

  arr[j].filters = [new BlurFilter(2,2,1),new GlowFilter(16711680,.6,2,2,4)];
  arr[j + 1].alpha = arr[j].alpha - .02;
}
//排列粒子坐标
function queue():void
{


  for (var i:uint =len; i > 0; i--)
  {
    arr[i].x = arr[i - 1].x;
    arr[i].y = arr[i - 1].y;
  }
}

this.addEventListener(Event.ENTER_FRAME,update);
//绕圆形运动
function update(e:Event)
{
  queue();

  //arr[0].x = this.mouseX;
  //arr[0].y = this.mouseY;
  arr[0].x = Math.cos(MathUtil.r2d(angle)) * radius + 225;
  arr[0].y = Math.sin(MathUtil.r2d(angle)) * radius + 200;
  angle +=  0.0004;
}

*各种运动效果需要自己调节相应参数实现。