js学习总结----简单的动画库封装tween.js

具体代码如下：

~function(){
    var myEffect = {
        Linear:function(t,b,c,d){
            return c*t/d+b
        },
        Quad: {//二次方的缓动（t^2）；
            easeIn: function(t,b,c,d){
                return c*(t/=d)*t + b;
            },
            easeOut: function(t,b,c,d){
                return -c *(t/=d)*(t-2) + b;
            },
            easeInOut: function(t,b,c,d){
                if ((t/=d/2) < 1) return c/2*t*t + b;
                return -c/2 * ((--t)*(t-2) - 1) + b;
            }
        },
        Cubic: {//三次方的缓动（t^3）
            easeIn: function(t,b,c,d){
                return c*(t/=d)*t*t + b;
            },
            easeOut: function(t,b,c,d){
                return c*((t=t/d-1)*t*t + 1) + b;
            },
            easeInOut: function(t,b,c,d){
                if ((t/=d/2) < 1) return c/2*t*t*t + b;
                return c/2*((t-=2)*t*t + 2) + b;
            }
        },
        Quart: {//四次方的缓动（t^4）；
            easeIn: function(t,b,c,d){
                return c*(t/=d)*t*t*t + b;
            },
            easeOut: function(t,b,c,d){
                return -c * ((t=t/d-1)*t*t*t - 1) + b;
            },
            easeInOut: function(t,b,c,d){
                if ((t/=d/2) < 1) return c/2*t*t*t*t + b;
                return -c/2 * ((t-=2)*t*t*t - 2) + b;
            }
        },
        Quint: {//5次方的缓动（t^5）；
            easeIn: function(t,b,c,d){
                return c*(t/=d)*t*t*t*t + b;
            },
            easeOut: function(t,b,c,d){
                return c*((t=t/d-1)*t*t*t*t + 1) + b;
            },
            easeInOut: function(t,b,c,d){
                if ((t/=d/2) < 1) return c/2*t*t*t*t*t + b;
                return c/2*((t-=2)*t*t*t*t + 2) + b;
            }
        },
        Sine: {//正弦曲线的缓动（sin(t)）
            easeIn: function(t,b,c,d){
                return -c * Math.cos(t/d * (Math.PI/2)) + c + b;
            },
            easeOut: function(t,b,c,d){
                return c * Math.sin(t/d * (Math.PI/2)) + b;
            },
            easeInOut: function(t,b,c,d){
                return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b;
            }
        },
        Expo: {//指数曲线的缓动（2^t）；
            easeIn: function(t,b,c,d){
                return (t==0) ? b : c * Math.pow(2, 10 * (t/d - 1)) + b;
            },
            easeOut: function(t,b,c,d){
                return (t==d) ? b+c : c * (-Math.pow(2, -10 * t/d) + 1) + b;
            },
            easeInOut: function(t,b,c,d){
                if (t==0) return b;
                if (t==d) return b+c;
                if ((t/=d/2) < 1) return c/2 * Math.pow(2, 10 * (t - 1)) + b;
                return c/2 * (-Math.pow(2, -10 * --t) + 2) + b;
            }
        },
        Circ: {//圆形曲线的缓动（sqrt(1-t^2)）；
            easeIn: function(t,b,c,d){
                return -c * (Math.sqrt(1 - (t/=d)*t) - 1) + b;
            },
            easeOut: function(t,b,c,d){
                return c * Math.sqrt(1 - (t=t/d-1)*t) + b;
            },
            easeInOut: function(t,b,c,d){
                if ((t/=d/2) < 1) return -c/2 * (Math.sqrt(1 - t*t) - 1) + b;
                return c/2 * (Math.sqrt(1 - (t-=2)*t) + 1) + b;
            }
        },
        Elastic: {//指数衰减的正弦曲线缓动；
            easeIn: function(t,b,c,d,a,p){
                if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*.3;
                if (!a || a < Math.abs(c)) { a=c; var s=p/4; }
                else var s = p/(2*Math.PI) * Math.asin (c/a);
                return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
            },
            easeOut: function(t,b,c,d,a,p){
                if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*.3;
                if (!a || a < Math.abs(c)) { a=c; var s=p/4; }
                else var s = p/(2*Math.PI) * Math.asin (c/a);
                return (a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b);
            },
            easeInOut: function(t,b,c,d,a,p){
                if (t==0) return b;  if ((t/=d/2)==2) return b+c;  if (!p) p=d*(.3*1.5);
                if (!a || a < Math.abs(c)) { a=c; var s=p/4; }
                else var s = p/(2*Math.PI) * Math.asin (c/a);
                if (t < 1) return -.5*(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
                return a*Math.pow(2,-10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )*.5 + c + b;
            }
        },
        Back: {//超过范围的三次方缓动（(s+1)*t^3 - s*t^2）；
            easeIn: function(t,b,c,d,s){
                if (s == undefined) s = 1.70158;
                return c*(t/=d)*t*((s+1)*t - s) + b;
            },
            easeOut: function(t,b,c,d,s){
                if (s == undefined) s = 1.70158;
                return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
            },
            easeInOut: function(t,b,c,d,s){
                if (s == undefined) s = 1.70158; 
                if ((t/=d/2) < 1) return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b;
                return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b;
            }
        },
        zfBounce: {//指数衰减的反弹缓动。
            easeIn: function(t,b,c,d){
                return c - zhufengEffect.zfBounce.easeOut(d-t, 0, c, d) + b;
            },
            easeOut: function(t,b,c,d){
                if ((t/=d) < (1/2.75)) {
                    return c*(7.5625*t*t) + b;
                } else if (t < (2/2.75)) {
                    return c*(7.5625*(t-=(1.5/2.75))*t + .75) + b;
                } else if (t < (2.5/2.75)) {
                    return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b;
                } else {
                    return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b;
                }
            },
            easeInOut: function(t,b,c,d){
                if (t < d/2) return zhufengEffect.zfBounce.easeIn(t*2, 0, c, d) * .5 + b;
                else return zhufengEffect.zfBounce.easeOut(t*2-d, 0, c, d) * .5 + c*.5 + b;
            }
        }
    };
    //move:实现多方向的运动动画
    /*
        curEle:当前要运动的元素
        target:当前动画的目标位置,存储的是每一个方向的目标位置{left:xxx,top:xxx...}
        duration:当前动画的总时间
    */
    //effect支持以下的情况
    /*
        
    */
    function move(curEle,target,duration,effect,callback){
        //处理我们需要的动画效果
        var tempEffect = myEffect.Linear;
        if(typeof effect === "number"){
            switch(effect){
                case 0:
                    tempEffect = myEffect.Linear;
                    break;
                case 1:
                    tempEffect = myEffect.Circ.easeInOut;
                    break;
                case 2:
                    tempEffect = myEffect.Elastic.easeOut;
                    break;
                case 3:
                    tempEffect = myEffect.Back.easeOut;
                    break;
                case 4:
                    tempEffect = myEffect.Bounce.easeOut;
                    break;
                case 5:
                    tempEffect = myEffect.Expo.easeIn;
            }
        }else if(effect instanceof Array){
            tempEffect = effect.length>=2 ? myEffect[effect[0]][effect[1]] : myEffect[effect[0]]
        }else if(typeof effect === "function"){
            //我们的实际意义应该是:effect是不传递值的，传递进来的函数应该是回调函数的值
            callback = effect;
        }

        //在每一次执行方法之前，首先把当前元素之前正在运行的动画结束掉
        window.clearInterval(curEle.timer);
        //根据target获取每一个方向的起始值begin和总距离change
        var begin = {},change = {};
        for(var key in target){
            if(target.hasOwnProperty(key)){
                begin[key] = utils.css(curEle,key)
                change[key] = target[key] - begin[key];

            }
        }
        //实现多方向的运动动画
        var time = 0;
        curEle.timer = window.setInterval(function(){
            time+=10;
            //到达目标：结束动画，让当前元素的样式值等于目标样式值
            if(time>=duration){
                utils.css(curEle,target);
                window.clearInterval(curEle.timer);
                //在动画结束的时候，如果用户把回调函数传递给我了，我就把用户传递的回调函数执行,不仅执行还把this的指向改为当前操作的元素

                typeof callback === "function" ? callback.call(curEle) : null;
                //或者callback && callback()
                return;
            }
            //没到达目标:分别获取每一个方向的当前位置，给当前位置设置样式即可。
            for(var key in target){
                if(target.hasOwnProperty(key)){
                    var curPos = tempEffect(time,begin[key],change[key],duration);
                    utils.css(curEle,key,curPos);
                }
            }
        },10)
    }

    window.myAnimate = move;
}()