前言
又到了白色相簿的季节，给博客加上雪花效果是再好不过的了。
这个效果是在jad大佬的博客看到的，然后就扒过来了。
插件特点:
- 较低的 CPU 消耗，移动端效果良好
- 原生 JavaScript 实现，不依赖其他类库
- 丰富的自定义项，可自定义多种选项
教程
1. 创建画布
在方便的地方插入以下代码：
1 | <canvas id="Snow"></canvas> |
2. 引入JS
重要的数值已在注释中给出
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 | (function() {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
window.requestAnimationFrame = requestAnimationFrame;
})();
(function() {
var flakes = [],
canvas = document.getElementById("Snow"), //画布ID，与上一步创建的画布对应
ctx = canvas.getContext("2d"),
flakeCount = 200, //雪花数量，数值越大雪花数量越多
mX = -100,
mY = -100;
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
function snow() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
for (var i = 0; i < flakeCount; i++) {
var flake = flakes[i],
x = mX,
y = mY,
minDist = 150, //雪花距离鼠标指针的最小值，小于这个距离的雪花将受到鼠标的排斥
x2 = flake.x,
y2 = flake.y;
var dist = Math.sqrt((x2 - x) * (x2 - x) + (y2 - y) * (y2 - y)),
dx = x2 - x,
dy = y2 - y;
if (dist < minDist) {
var force = minDist / (dist * dist),
xcomp = (x - x2) / dist,
ycomp = (y - y2) / dist,
deltaV = force / 2;
flake.velX -= deltaV * xcomp;
flake.velY -= deltaV * ycomp;
} else {
flake.velX *= .98;
if (flake.velY <= flake.speed) {
flake.velY = flake.speed
}
flake.velX += Math.cos(flake.step += .05) * flake.stepSize;
}
ctx.fillStyle = "rgba(255,255,255," + flake.opacity + ")"; //雪花颜色
flake.y += flake.velY;
flake.x += flake.velX;
if (flake.y >= canvas.height || flake.y <= 0) {
reset(flake);
}
if (flake.x >= canvas.width || flake.x <= 0) {
reset(flake);
}
ctx.beginPath();
ctx.arc(flake.x, flake.y, flake.size, 0, Math.PI * 2);
ctx.fill();
}
requestAnimationFrame(snow);
};
function reset(flake) {
flake.x = Math.floor(Math.random() * canvas.width);
flake.y = 0;
flake.size = (Math.random() * 3) + 2; //加号后面的值，雪花大小，为基准值，数值越大雪花越大
flake.speed = (Math.random() * 1) + 0.5; //加号后面的值，雪花速度，为基准值，数值越大雪花速度越快
flake.velY = flake.speed;
flake.velX = 0;
flake.opacity = (Math.random() * 0.5) + 0.3; //加号后面的值，为基准值，范围0~1
}
function init() {
for (var i = 0; i < flakeCount; i++) {
var x = Math.floor(Math.random() * canvas.width),
y = Math.floor(Math.random() * canvas.height),
size = (Math.random() * 3) + 2, //加号后面的值，雪花大小，为基准值，数值越大雪花越大
speed = (Math.random() * 1) + 0.5, //加号后面的值，雪花速度，为基准值，数值越大雪花速度越快
opacity = (Math.random() * 0.5) + 0.3; //加号后面的值，为基准值，范围0~1
flakes.push({
speed: speed,
velY: speed,
velX: 0,
x: x,
y: y,
size: size,
stepSize: (Math.random()) / 30 * 1, //乘号后面的值，雪花横移幅度，为基准值，数值越大雪花横移幅度越大，0为竖直下落
step: 0,
angle: 180,
opacity: opacity
});
}
snow();
};
document.addEventListener("mousemove", function(e) {
mX = e.clientX,
mY = e.clientY
});
window.addEventListener("resize", function() {
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
});
init();
})(); |
3. 引入CSS
背景颜色可根据自身需要改变
1 2 3 4 5 6 7 8 9 10 | #Snow{
position: fixed;
top: 0;
left: 0;
width: 100%;
height: 100%;
z-index: 99999;
background: rgba(125,137,95,0.1);
pointer-events: none;
} |