网页樱花飘落特效
在博客侧边栏公告（支持HTML代码） （支持 JS 代码）加入下面1行代码便可以拥有同博主的樱花特效解读
//樱花 Quaint 修改版 var stop, staticx; var img = new Image(); img.src = "这里原js作者高明操作,请看源码,如何进制转成樱花"; // 樱花数量 (添加) var sakuraNum = 21; // 樱花越界限制次数, -1不做限制,无限循环 (添加) var limitTimes = 2; // 定义限制数组 (添加) var limitArray = new Array(sakuraNum); for(var index = 0;index < sakuraNum;index++){ limitArray = limitTimes; } // 定义樱花, idx 是修改添加的 function Sakura(x, y, s, r, fn, idx) { this.x = x; this.y = y; this.s = s; this.r = r; this.fn = fn; this.idx = idx; } // 绘制樱花 Sakura.prototype.draw = function(cxt) { cxt.save(); var xc = 40 * this.s / 4; cxt.translate(this.x, this.y); cxt.rotate(this.r); cxt.drawImage(img, 0, 0, 40 * this.s, 40 * this.s) cxt.restore(); } // 修改樱花位置,模拟飘落. Sakura.prototype.update = function() { this.x = this.fn.x(this.x, this.y); this.y = this.fn.y(this.y, this.y); this.r = this.fn.r(this.r); // 如果樱花越界, 重新调整位置 if(this.x > window.innerWidth || this.x < 0 || this.y > window.innerHeight || this.y < 0) { // 如果樱花不做限制 if (limitArray == -1) { this.r = getRandom('fnr'); if(Math.random() > 0.4) { this.x = getRandom('x'); this.y = 0; this.s = getRandom('s'); this.r = getRandom('r'); } else { this.x = window.innerWidth; this.y = getRandom('y'); this.s = getRandom('s'); this.r = getRandom('r'); } } // 否则樱花有限制 else { if (limitArray > 0) { this.r = getRandom('fnr'); if(Math.random() > 0.4) { this.x = getRandom('x'); this.y = 0; this.s = getRandom('s'); this.r = getRandom('r'); } else { this.x = window.innerWidth; this.y = getRandom('y'); this.s = getRandom('s'); this.r = getRandom('r'); } // 该越界的樱花限制数减一 limitArray--; } } } } SakuraList = function() { this.list = []; } SakuraList.prototype.push = function(sakura) { this.list.push(sakura); } // list update 方法 SakuraList.prototype.update = function() { for(var i = 0, len = this.list.length; i < len; i++) { this.list.update(); } } // list draw 方法 SakuraList.prototype.draw = function(cxt) { for(var i = 0, len = this.list.length; i < len; i++) { this.list.draw(cxt); } } SakuraList.prototype.get = function(i) { return this.list; } SakuraList.prototype.size = function() { return this.list.length; } // 位置随机策略 function getRandom(option) { var ret, random; switch(option) { case 'x': ret = Math.random() * window.innerWidth; break; case 'y': ret = Math.random() * window.innerHeight; break; case 's': ret = Math.random(); break; case 'r': ret = Math.random() * 6; break; case 'fnx': random = -0.5 + Math.random() * 1; ret = function(x, y) { return x + 0.5 * random - 1.7; }; break; case 'fny': random = 1.5 + Math.random() * 0.7 ret = function(x, y) { return y + random; }; break; case 'fnr': random = Math.random() * 0.03; ret = function(r) { return r + random; }; break; } return ret; } // 樱花入口 function startSakura() { requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame || window.oRequestAnimationFrame; var canvas = document.createElement('canvas'), cxt; staticx = true; canvas.height = window.innerHeight; canvas.width = window.innerWidth; canvas.setAttribute('style', 'position: fixed;left: 0;top: 0;pointer-events: none;'); canvas.setAttribute('id', 'canvas_sakura'); document.getElementsByTagName('body').appendChild(canvas); cxt = canvas.getContext('2d'); var sakuraList = new SakuraList(); // sakuraNum 樱花个数 (原版为50个) for(var i = 0; i < sakuraNum; i++) { var sakura, randomX, randomY, randomS, randomR, randomFnx, randomFny; randomX = getRandom('x'); randomY = getRandom('y'); randomR = getRandom('r'); randomS = getRandom('s'); randomFnx = getRandom('fnx'); randomFny = getRandom('fny'); randomFnR = getRandom('fnr'); sakura = new Sakura(randomX, randomY, randomS, randomR, { x: randomFnx, y: randomFny, r: randomFnR }, i); sakura.draw(cxt); sakuraList.push(sakura); } stop = requestAnimationFrame(function() { cxt.clearRect(0, 0, canvas.width, canvas.height); // 修改樱花位置逻辑 sakuraList.update(); // 画出修改后的樱花 sakuraList.draw(cxt); // 递归 修改位置, 画出修改后的樱花 stop = requestAnimationFrame(arguments.callee); }) } window.onresize = function() { var canvasSnow = document.getElementById('canvas_snow'); // canvasSnow 在改变浏览器大小的时候会为null (修改空指针异常), 不过在改变大小时体验稍差 if (canvasSnow) { canvasSnow.width = window.innerWidth; canvasSnow.height = window.innerHeight; } } img.onload = function() { startSakura(); } // 没看懂哪里调用了, 应该是关闭樱花特效的方法. 还请大佬们解释自己是怎么使用的. function stopp() { if(staticx) { var child = document.getElementById("canvas_sakura"); child.parentNode.removeChild(child); window.cancelAnimationFrame(stop); staticx = false; } else { startSakura(); } }
虽然不知道原版代码是谁写的, 不过还是感谢制作该特效的大佬
致谢
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