动画创作-下雪的动画脚本

package

{

import flash.display.*;

import flash.events.*;

public class SnowFlake extends MovieClip

{

var radians = 0;//radians

var speed = 0;

var radius = 5;

var stageHeight;

public function SnowFlake (h:Number)

{

speed =.01+.5*Math.random();

radius =.1+2*Math.random();

stageHeight = h;

this.addEventListener (Event.ENTER_FRAME,Snowing);

//这个this是库中的SnowFlake影片剪辑

}

function Snowing (e:Event):void

{

radians += speed;

this.x += Math.round(Math.cos(radians));

this.y += 2;

if (this.y > stageHeight)

{

this.y = -20;

}

}

}

}

import SnowFlake;

function DisplaySnow ()

{

for (var i:int=0; i

//最多产生30个雪花

var _SnowFlake:SnowFlake = new SnowFlake(300);

this.addChild (_SnowFlake);

_SnowFlake.x =Math.random()*600;

_SnowFlake.y =Math.random()*400;

//在600×400范围内随机产生雪花

_SnowFlake.alpha = .2+Math.random()*5;

//设置雪花随机透明度

var scale:Number = .3+Math.random()*2;

//设置雪花随机大小

_SnowFlake.scaleX =_SnowFlake.scaleY =scale;

//按随机比例放大雪花。

}

}

DisplaySnow();