原生JS实现翻书翻页动画效果

<!doctype html>
<html>
 
    <head>
        <meta charset="utf-8">
        <title>原生JS实现翻书特效</title>
        <style type="text/css">
            * {
                margin: 0;
                padding: 0;
                list-style: none;
            }
 
            #btn {
                width: 50px;
                height: 40px;
                line-height: 40px;
                position: relative;
                left: 50%;
                margin-left: -25px;
                top: 100px;
            }
 
            #book {
                width: 600px;
                height: 400px;
                position: absolute;
                left: 50%;
                top: 50%;
                margin: -200px 0 0 -300px;
                border: 1px solid black;
                /* 第一个封面 */
                background: url(images/0.jpg);
            }
 
            #rightPage {
                width: 50%;
                height: 100%;
                position: absolute;
                left: 50%;
                z-index: 2;
                transition: 0.5s;
                transform: perspective(800px) rotateY(0px);
                transform-origin: left center;
                background: black;
                transform-style: preserve-3d;
            }
 
            #rightPage #topNode {
                position: absolute;
                width: 100%;
                height: 100%;
                /* 第一个封面 */
                background: url(images/0.jpg) 300px 0;
                transform: translateZ(1px);
            }
 
            #rightPage #bottomNode {
                position: absolute;
                width: 100%;
                height: 100%;
                /* 第三个封面 */
                background: url(images/2.jpg) 0 0;
                /*scaleX将翻书镜像后的图像还原镜像*/
                transform: translateZ(-1px) scaleX(-1);
            }
 
            #rightOtherPage {
                position: absolute;
                left: 50%;
                height: 100%;
                width: 50%;
                /* 第三个封面 */
                background: url(images/2.jpg) 300px 0;
                z-index: 1;
            }
        </style>
    </head>
 
    <body>
        <input type='button' value='下一页' id='btn'>
        <div id='book'>
            <div id='rightPage'>
                <div id='topNode'></div>
                <div id='bottomNode'></div>
            </div>
            <div id='rightOtherPage'></div>
        </div>
        <script type="text/javascript">
            var index = 0;
            var flag = false;
 
            btn.onclick = function () {
                if (flag) return;
                flag = true;
                index++;
                rightPage.style.transition = '0.5s';
                rightPage.style.transform = 'perspective(800px) rotateY(-180deg)';
 
                setTimeout(function () {
                    // 翻页后瞬间更换下一页的背景
                    book.style.backgroundImage = 'url(images/' + (index % 2 + 1) + '.jpg)';
                    // 让翻页瞬间回去
                    rightPage.style.transition = '0s';
                    rightPage.style.transform = 'perspective(800px) rotateY(0deg)';
 
                    // 更换翻页纸正面背景
                    topNode.style.backgroundImage = 'url(images/' + (index % 2 + 1) + '.jpg)';
                    // 更换翻页纸背面背景
                    bottomNode.style.backgroundImage = 'url(images/' + ((index + 1) % 2 + 1) + '.jpg)';
 
                    // 更换翻页后的纸背景
                    rightOtherPage.style.backgroundImage = 'url(images/' + ((index + 1) % 2 + 1) + '.jpg)';
                    flag = false;
 
                }, 500);
 
            };
        </script>
    </body>
 
</html>