下雪特效代码 一、下雪特效代码①<script type="text/javascript"> /* 控制下雪 */ function snowFall(snow) { /* 可配置属性 */ snow = snow || {}; this.maxFlake = snow.maxFlake || 520; /* 最多片数 */ this.flakeSize = snow.flakeSize || 10; /* 雪花形状 */ this.fallSpeed = snow.fallSpeed || 1; /* 坠落速度 */ } /* 兼容写法 */ requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame || window.oRequestAnimationFrame || function(callback) { setTimeout(callback, 1000 / 60); }; cancelAnimationFrame = window.cancelAnimationFrame || window.mozCancelAnimationFrame || window.webkitCancelAnimationFrame || window.msCancelAnimationFrame || window.oCancelAnimationFrame; /* 开始下雪 */ snowFall.prototype.start = function(){ /* 创建画布 */ snowCanvas.apply(this); /* 创建雪花形状 */ createFlakes.apply(this); /* 画雪 */ drawSnow.apply(this) } /* 创建画布 */ function snowCanvas() { /* 添加Dom结点 */ var snowcanvas = document.createElement("canvas"); snowcanvas.id = "snowfall"; snowcanvas.width = window.innerWidth; snowcanvas.height = document.body.clientHeight; snowcanvas.setAttribute("style", "position:absolute; top: 0; left: 0; z-index: 1; pointer-events: none;"); document.getElementsByTagName("body")[0].appendChild(snowcanvas); this.canvas = snowcanvas; this.ctx = snowcanvas.getContext("2d"); /* 窗口大小改变的处理 */ window.onresize = function() { snowcanvas.width = window.innerWidth; /* snowcanvas.height = window.innerHeight */ } } /* 雪运动对象 */ function flakeMove(canvasWidth, canvasHeight, flakeSize, fallSpeed) { this.x = Math.floor(Math.random() * canvasWidth); /* x坐标 */ this.y = Math.floor(Math.random() * canvasHeight); /* y坐标 */ this.size = Math.random() * flakeSize + 2; /* 形状 */ this.maxSize = flakeSize; /* 最大形状 */ this.speed = Math.random() * 1 + fallSpeed; /* 坠落速度 */ this.fallSpeed = fallSpeed; /* 坠落速度 */ this.velY = this.speed; /* Y方向速度 */ this.velX = 0; /* X方向速度 */ this.stepSize = Math.random() / 30; /* 步长 */ this.step = 0 /* 步数 */ } flakeMove.prototype.update = function() { var x = this.x, y = this.y; /* 左右摆动(余弦) */ this.velX *= 0.98; if (this.velY <= this.speed) { this.velY = this.speed } this.velX += Math.cos(this.step += .05) * this.stepSize; this.y += this.velY; this.x += this.velX; /* 飞出边界的处理 */ if (this.x >= canvas.width || this.x <= 0 || this.y >= canvas.height || this.y <= 0) { this.reset(canvas.width, canvas.height) } }; /* 飞出边界-放置最顶端继续坠落 */ flakeMove.prototype.reset = function(width, height) { this.x = Math.floor(Math.random() * width); this.y = 0; this.size = Math.random() * this.maxSize + 2; this.speed = Math.random() * 1 + this.fallSpeed; this.velY = this.speed; this.velX = 0; }; // 渲染雪花-随机形状（此处可修改雪花颜色！！！） flakeMove.prototype.render = function(ctx) { var snowFlake = ctx.createRadialGradient(this.x, this.y, 0, this.x, this.y, this.size); snowFlake.addColorStop(0, "rgba(255, 255, 255, 0.9)"); /* 此处是雪花颜色，默认是白色 */ snowFlake.addColorStop(.5, "rgba(255, 255, 255, 0.5)"); /* 若要改为其他颜色，请自行查 */ snowFlake.addColorStop(1, "rgba(255, 255, 255, 0)"); /* 找16进制的RGB 颜色代码。 */ ctx.save(); ctx.fillStyle = snowFlake; ctx.beginPath(); ctx.arc(this.x, this.y, this.size, 0, Math.PI * 2); ctx.fill(); ctx.restore(); }; /* 创建雪花-定义形状 */ function createFlakes() { var maxFlake = this.maxFlake, flakes = this.flakes = [], canvas = this.canvas; for (var i = 0; i < maxFlake; i++) { flakes.push(new flakeMove(canvas.width, canvas.height, this.flakeSize, this.fallSpeed)) } } /* 画雪 */ function drawSnow() { var maxFlake = this.maxFlake, flakes = this.flakes; ctx = this.ctx, canvas = this.canvas, that = this; /* 清空雪花 */ ctx.clearRect(0, 0, canvas.width, canvas.height); for (var e = 0; e < maxFlake; e++) { flakes[e].update(); flakes[e].render(ctx); } /* 一帧一帧的画 */ this.loop = requestAnimationFrame(function() { drawSnow.apply(that); }); } /* 调用及控制方法 */ var snow = new snowFall({maxFlake:60}); snow.start(); </script>二、下雪特效代码② 　 <script type="text/javascript"> (function($){ $.fn.snow = function(options){ var $flake = $('<div id="snowbox" />').css({'position': 'absolute','z-index':'9999', 'top': '-50px', 'cursor': 'pointer'}).html('❄'), documentHeight = $(document).height(), documentWidth = $(document).width(), defaults = { minSize : 10, maxSize : 20, newOn : 1000, flakeColor : "#AFDAEF" /* 此处可以定义雪花颜色，若要白色可以改为#FFFFFF */ }, options = $.extend({}, defaults, options); var interval= setInterval( function(){ var startPositionLeft = Math.random() * documentWidth - 100, startOpacity = 0.5 + Math.random(), sizeFlake = options.minSize + Math.random() * options.maxSize, endPositionTop = documentHeight - 200, endPositionLeft = startPositionLeft - 500 + Math.random() * 500, durationFall = documentHeight * 10 + Math.random() * 5000; $flake.clone().appendTo('body').css({ left: startPositionLeft, opacity: startOpacity, 'font-size': sizeFlake, color: options.flakeColor }).animate({ top: endPositionTop, left: endPositionLeft, opacity: 0.2 },durationFall,'linear',function(){ $(this).remove() }); }, options.newOn); }; })(jQuery); $(function(){ $.fn.snow({ minSize: 5, /* 定义雪花最小尺寸 */ maxSize: 50,/* 定义雪花最大尺寸 */ newOn: 300 /* 定义密集程度，数字越小越密集 */ }); }); </script> 三、下雪特效代码③<script type="text/javascript"> window.onload = function () { var minSize = 5; //最小字体 var maxSize = 50;//最大字体 var newOne = 100; //生成雪花间隔 var flakColor = "#fff"; //雪花颜色 var flak = $("<div></div>").css({position:"absolute","top":"0px"}).html("❉");//定义一个雪花 var dhight = $(window).height(); //定义视图高度 var dw =$(window).width()-80; //定义视图宽度 setInterval(function(){ var sizeflak = minSize+Math.random()*maxSize; //产生大小不等的雪花 var startLeft = Math.random()*dw; //雪花生成是随机的left值 var startOpacity = 0.7+Math.random()*0.3; //随机透明度 var endTop= dhight-100; //雪花停止top的位置 var endLeft= Math.random()*dw; //雪花停止的left位置 var durationfull = 5000+Math.random()*5000; //雪花飘落速度不同 flak.clone().appendTo($("body")).css({ "left":startLeft , "opacity":startOpacity, "font-size":sizeflak, "color":flakColor }).animate({ "top":endTop, "left":endLeft, "apacity":0.1 },durationfull,function(){ $(this).remove() }); },newOne); } </script>