flash 代码 雪花飘落

var frameTime = 4;

var sceneWidth = 400;　　//屏幕宽度

var sceneHeight = 400;　　//屏幕高度

var removeSnow = 100;　　//雪花数量

var speed = 40;　　//雪花速度

var distance = -0.3;

this.onEnterFrame = function () {
 if (random (frameTime) == 0) {
  mc = this.snow.duplicateMovieClip ("snow"+i, i+100);     //snow为雪花。
  mc._x = random (sceneWidth);
  mc._xscale = mc._yscale=random (50)+50;
  mc._alpha = mc._xscale;
  mc._y = 0;
  mc.s = random (100);
  mc.onEnterFrame = function () {
   this._y += this._xscale/speed;
   this._x += random (2)-0.5+distance;
   if (targetMc.hitTest (this._x, this._y, true)) {        //targetMc为物体，雪花会放置与该物体上，然后溶化，消失。
    mc = _root.snow.duplicateMovieClip ("dusnow"+j, j);
    mc._x = this._x;
    mc._y = this._y;
    mc._alpha = this._alpha;
    mc._xscale = mc._yscale=this._xscale;
    mc.onEnterFrame = function () {
     if (this.t++>removeSnow) {
      this._alpha -= 5;
      if (this._alpha<0) {
       this.removeMovieClip ();
      }
     }
    };
    j++;
    this.removeMovieClip ();
   }
   if (this._x<0 || this._x>sceneWidth || this._y>sceneHeight) {
    this.removeMovieClip ();
   }
  };
  i++;
 }
};

var frameTime = 10;

var sceneWidth = 400;

var sceneHeight = 400;

var speed = 40;

var vibration = 20;

this.onEnterFrame = function () {
 if (random (frameTime) == 0) {
  mc = this.snowMc.duplicateMovieClip ("snowMc"+i, i+100);
  mc._x = random (sceneWidth);
  mc._xscale = mc._yscale=random (50)+50;
  mc._alpha = mc._xscale;
  mc._y = 0;
  mc.s = random (100);
  mc.onEnterFrame = function () {
   this._y += this._xscale/speed;
   this._x += Math.sin (this.s++/vibration);
   if (this._y>sceneHeight) {
    this.removeMovieClip ();
   }
  };
  i++;
 }
};