<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>雪花特效</title>
<style>
* {
padding: 0;
margin: 0;
}
.content {
width: 100vw;
height: 100vh;
background: url(https://xn--xu0a.cn/api/dn/) center center no-repeat;
background-size: cover;
}
#snowfall {
position: fixed;
top: 0;
left: 0;
width: 100vw;
height: 100vh;
pointer-events: none;
z-index: 1;
}
.snow {
position: absolute;
width: 2px;
height: 50px;
background: linear-gradient(rgba(255, 255, 255, .3), rgba(255, 255, 255, .6));
}
</style>
<style type="text/css">
@font-face {
font-family: TencentSans;
src: url("chrome-extension://lkjkfecdnfjopaeaibboihfkmhdjmanm/static/fonts/TencentSans.woff2");
}
</style>
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
</head>
<body>
<div class="content">
<canvas id="snowfall"></canvas>
<div id="rainBox"></div>
</div>
<script>
/* 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 = window.innerHeight;
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>
</body>
</html>
