[ActionScript 3.0] 喷泉效果

pall为水珠影片剪辑

var count:int = 500;
var zl:Number = 0.5;
var balls:Array;
balls = new Array();
for (var i:int = 0; i < count; i++)
{
    var ball:pall = new pall();
    ball.x = 260;
    ball.y = 300;
    ball["vx"] = Math.random() * 2 - 1;
    ball["vy"] = Math.random() * -10 - 10;
    addChild(ball);
    balls.push(ball);
}
addEventListener(Event.ENTER_FRAME, onEnterFrame);
function onEnterFrame(event:Event):void
{
    for (var i:Number = 0; i < balls.length; i++)
    {
        var ball:pall = pall(balls[i]);
        ball["vy"] +=  zl;
        ball.x +=  ball["vx"];
        ball.y +=  ball["vy"];
        if (ball.x - ball.width/2> stage.stageWidth ||
        ball.x + ball.width/2 < 0 ||
        ball.y - ball.width/2 > stage.stageHeight ||
        ball.y + ball.width/2 < 0)
        {
            ball.x = 260;
            ball.y = 300;
            ball["vx"] = Math.random() * 2 - 1;
            ball["vy"] = Math.random() * -10 - 10;
        }
    }
}