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- 2024-11-23
 
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- <script type="text/javascript">
- /* 控制下雪 */
- function snowFall(snow) {
- /* 可配置属性 */
- snow = snow || {};
- this.maxFlake = snow.maxFlake || 200; /* 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:500});
- snow.start();
- </script>
这个也可以哈哈，不过不如版主的样式多，测试结果：测试雪花 |
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