js动画(animate)简单引擎代码示例(2)

this.timmer = setInterval(function() {
            if (that.complete()) {
                that.stop();
                that.running = false;
                if (callback) {
                    callback.call(that);
                }
                return;
            }
            that.curframe++;
            that.enterFrame.call(that);
        },
 / this.fps);

return this;
    },
    // 停止动画
    stop: function() {
        //console.log('结束动画！');
        if (this.timmer) {
            clearInterval(this.timmer);
            // 清除掉timmer id
            this.timmer = undefined;
        }

},
    go: function(props, duration, tween) {
        var that = this;
        //console.log(tween)
        this.ms.push(function() {
            that.init.call(that, props, duration, tween);
            that.play.call(that, that.start);
        });
        return this;
    },
    //向后一帧
    next: function() {
        this.stop();
        this.curframe++;
        this.curframe = this.curframe > this.frames ? this.frames: this.curframe;
        this.enterFrame.call(this);
    },
    //向前一帧
    prev: function() {
        this.stop();
        this.curframe--;
        this.curframe = this.curframe < 0 ? 0 : this.curframe;
        this.enterFrame.call(this);
    },
    //跳跃到指定帧并播放
    gotoAndPlay: function(frame) {
        this.stop();
        this.curframe = frame;
        this.play.call(this);
    },
    //跳到指定帧停止播放
    gotoAndStop: function(frame) {
        this.stop();
        this.curframe = frame;
        this.enterFrame.call(this);
    },
    //进入帧动作
    enterFrame: function() {
        //console.log('进入帧：' + this.curframe)
        var ds;
        for (var prop in this.initstate) {
            //console.log('from: ' + this.initstate[prop]['from'])
            ds = this.tween(this.curframe, this.initstate[prop]['from'], this.initstate[prop]['to'] - this.initstate[prop]['from'], this.frames).toFixed(2);
            //console.log(prop + ':' + ds)
            $util.dom.setStyle(this.obj, prop, ds)
        }
    },
    //动画结束
    complete: function() {
        return this.curframe >= this.frames;
    },
    hasNext: function() {
        return this.ms.length > 0;
    }
}

下面是一个简单的工具,其中有所用到的缓动公式：

util.js

复制代码 代码如下: