本文实例为大家分享了js实现商品抛物线加入购物车动画代码，供大家参考，具体内容如下
parapola.js
/*! * by zhangxinxu(.com) 2012-12-27 * you can visit http://www.zhangxinxu.com/wordpress/?p=3855 to get more infomation * under MIT license*/var funParabola = function(element, target, options) { /* * 网页模拟现实需要一个比例尺 * 如果按照1像素就是1米来算，显然不合适，因为页面动不动就几百像素 * 页面上，我们放两个物体，200~800像素之间，我们可以映射为现实世界的2米到8米，也就是100:1 * 不过，本方法没有对此有所体现，因此不必在意 */ var defaults = { speed: 166.67, // 每帧移动的像素大小，每帧（对于大部分显示屏）大约16~17毫秒 curvature: 0.001, // 实际指焦点到准线的距离，你可以抽象成曲率，这里模拟扔物体的抛物线，因此是开口向下的 progress: function() {}, complete: function() {} }; var params = {}; options = options || {}; for (var key in defaults) { params[key] = options[key] || defaults[key]; } var exports = { mark: function() { return this; }, position: function() { return this; }, move: function() { return this; }, init: function() { return this; } }; /* 确定移动的方式 * IE6-IE8 是margin位移 * IE9+使用transform */ var moveStyle = "margin", testDiv = document.createElement("div"); if ("oninput" in testDiv) { ["", "ms", "webkit"].forEach(function(prefix) { var transform = prefix + (prefix? "T": "t") + "ransform"; if (transform in testDiv.style) { moveStyle = transform; } }); } // 根据两点坐标以及曲率确定运动曲线函数（也就是确定a, b的值） /* 公式： y = a*x*x + b*x + c; */ var a = params.curvature, b = 0, c = 0; // 是否执行运动的标志量 var flagMove = true; if (element && target && element.nodeType == 1 && target.nodeType == 1) { var rectElement = {}, rectTarget = {}; // 移动元素的中心点位置，目标元素的中心点位置 var centerElement = {}, centerTarget = {}; // 目标元素的坐标位置 var coordElement = {}, coordTarget = {}; // 标注当前元素的坐标 exports.mark = function() { if (flagMove == false) return this; if (typeof coordElement.x == "undefined") this.position(); element.setAttribute("data-center", [coordElement.x, coordElement.y].join()); target.setAttribute("data-center", [coordTarget.x, coordTarget.y].join()); return this; } exports.position = function() { if (flagMove == false) return this; var scrollLeft = document.documentElement.scrollLeft || document.body.scrollLeft, scrollTop = document.documentElement.scrollTop || document.body.scrollTop; // 初始位置 if (moveStyle == "margin") { element.style.marginLeft = element.style.marginTop = "0px"; } else { element.style[moveStyle] = "translate(0, 0)"; } // 四边缘的坐标 rectElement = element.getBoundingClientRect(); rectTarget = target.getBoundingClientRect(); // 移动元素的中心点坐标 centerElement = { x: rectElement.left + (rectElement.right - rectElement.left) / 2 + scrollLeft, y: rectElement.top + (rectElement.bottom - rectElement.top) / 2 + scrollTop }; // 目标元素的中心点位置 centerTarget = { x: rectTarget.left + (rectTarget.right - rectTarget.left) / 2 + scrollLeft, y: rectTarget.top + (rectTarget.bottom - rectTarget.top) / 2 + scrollTop }; // 转换成相对坐标位置 coordElement = { x: 0, y: 0 }; coordTarget = { x: -1 * (centerElement.x - centerTarget.x), y: -1 * (centerElement.y - centerTarget.y) }; /* * 因为经过(0, 0), 因此c = 0 * 于是： * y = a * x*x + b*x; * y1 = a * x1*x1 + b*x1; * y2 = a * x2*x2 + b*x2; * 利用第二个坐标： * b = (y2+ a*x2*x2) / x2 */ // 于是 b = (coordTarget.y - a * coordTarget.x * coordTarget.x) / coordTarget.x; return this; }; // 按照这个曲线运动 exports.move = function() { // 如果曲线运动还没有结束，不再执行新的运动 if (flagMove == false) return this; var startx = 0, rate = coordTarget.x > 0? 1: -1; var step = function() { // 切线 y'=2ax+b var tangent = 2 * a * startx + b; // = y / x // y*y + x*x = speed // (tangent * x)^2 + x*x = speed // x = Math.sqr(speed / (tangent * tangent + 1)); startx = startx + rate * Math.sqrt(params.speed / (tangent * tangent + 1)); // 防止过界 if ((rate == 1 && startx > coordTarget.x) || (rate == -1 && startx < coordTarget.x)) { startx = coordTarget.x; } var x = startx, y = a * x * x + b * x; // 标记当前位置，这里有测试使用的嫌疑，实际使用可以将这一行注释 element.setAttribute("data-center", [Math.round(x), Math.round(y)].join()); // x, y目前是坐标，需要转换成定位的像素值 if (moveStyle == "margin") { element.style.marginLeft = x + "px"; element.style.marginTop = y + "px"; } else { element.style[moveStyle] = "translate("+ [x + "px", y + "px"].join() +")"; } if (startx !== coordTarget.x) { params.progress(x, y); window.requestAnimationFrame(step); } else { // 运动结束，回调执行 params.complete(); flagMove = true; } }; window.requestAnimationFrame(step); flagMove = false; return this; }; // 初始化方法 exports.init = function() { this.position().mark().move(); }; } return exports;};/*! requestAnimationFrame.js * by zhangxinxu 2013-09-30*/(function() { var lastTime = 0; var vendors = ['webkit', 'moz']; for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) { window.requestAnimationFrame = window[vendors[x] + 'RequestAnimationFrame']; window.cancelAnimationFrame = window[vendors[x] + 'CancelAnimationFrame'] || // name has changed in Webkit window[vendors[x] + 'CancelRequestAnimationFrame']; } if (!window.requestAnimationFrame) { window.requestAnimationFrame = function(callback, element) { var currTime = new Date().getTime(); var timeToCall = Math.max(0, 16.7 - (currTime - lastTime)); var id = window.setTimeout(function() { callback(currTime + timeToCall); }, timeToCall); lastTime = currTime + timeToCall; return id; }; } if (!window.cancelAnimationFrame) { window.cancelAnimationFrame = function(id) { clearTimeout(id); }; }}());使用：
/* 元素 */var element = document.getElementById("element"), target = document.getElementById("target");// 抛物线元素的的位置标记var parabola = funParabola(element, target).mark();// 抛物线运动的触发document.body.onclick = function() { element.style.marginLeft = "0px"; element.style.marginTop = "0px"; parabola.init();};加入购物车实战：
/* 本demo演示脚本基于ieBetter.js, 项目地址：https://github.com/zhangxinxu/ieBetter.js */// 元素以及其他一些变量var eleFlyElement = document.querySelector("#flyItem"), eleShopCart = document.querySelector("#shopCart");var numberItem = 0;// 抛物线运动var myParabola = funParabola(eleFlyElement, eleShopCart, { speed: 400, curvature: 0.002, complete: function() { eleFlyElement.style.visibility = "hidden"; eleShopCart.querySelector("span").innerHTML = ++numberItem; }});// 绑定点击事件if (eleFlyElement && eleShopCart) { [].slice.call(document.getElementsByClassName("btnCart")).forEach(function(button) { button.addEventListener("click", function() { // 滚动大小 var scrollLeft = document.documentElement.scrollLeft || document.body.scrollLeft || 0, scrollTop = document.documentElement.scrollTop || document.body.scrollTop || 0; eleFlyElement.style.left = event.clientX + scrollLeft + "px"; eleFlyElement.style.top = event.clientY + scrollTop + "px"; eleFlyElement.style.visibility = "visible"; // 需要重定位 myParabola.position().move(); }); });}以上就是本文的全部内容，希望对大家的学习有所帮助。