Flash利用材质和遮照创建真实的小球动画

Flash利用材质和遮照创建真实的小球动画(3) yspeed = 0;
xspeed = 0;
friction = 0.95;
_root.attachMovie("ball", "ball", 1, {_x:250, _y:175});
ball.texture.setMask(ball.ball_itself);
ball.onEnterFrame = function() {
    if (Key.isDown(Key.LEFT)) {
        xspeed -= power;
    }
    if (Key.isDown(Key.RIGHT)) {
        xspeed += power;
    }
    if (Key.isDown(Key.UP)) {
        yspeed -= power;
    }
    if (Key.isDown(Key.DOWN)) {
        yspeed += power;
    }
    xspeed *= friction;
    yspeed *= friction;
    this._y += yspeed;
    this._x += xspeed;
    this.texture._y += yspeed;
    this.texture._x += xspeed;
    if (this.texture._x>158) {
        this.texture._x -= 188;
    }
    if (this.texture._x<-158) {
        this.texture._x += 188;
    }
    if (this.texture._y>158) {
        this.texture._y -= 188;
    }
    if (this.texture._y<-158) {
        this.texture._y += 188;
    }
};

　　效果如下：