博客雪花特效
0
悬赏园豆：180
[已解决问题]
解决于 2023-02-28 19:39
大佬我想请教一下这个博客的雪花飘落特效是怎么做的，我查了网上的资料，照着做，但是雪花上半部分会被背景挡住，怎么让它在背景图层顶部出现
最佳答案
1
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<style type="text/css">
body {
width: 100%;
height: 100%;
padding:0px;
margin:0px;
}
</style>
</head>
<body>
<canvas id="Snow" style="width:100%;height:100%;"></canvas>
<script type="text/javascript">
(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 = 30, //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(0,255,255," + 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) + 8; //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) + 1; //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) + 8, //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) + 1, //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();
})();
</script>
</body>
</html>
收获园豆：120
我試了一下是可以的 可能是你沒有調好畫布的大小
可是画布不是直接用 canvas.width = window.innerWidth;
canvas.height = window.innerHeight;获取吗，该怎么调
@jesion_wang: 是的 那是設置畫布大小 <canvas id="Snow"></canvas> 直接這樣就可以了
其他回答(1)
0
z-index:100000;
收获园豆：60
不行
@jesion_wang:
搜一下那个背景，查看它的z-index是多少，比它多1就行，哈哈。
@jesion_wang:
你看我博客的飘叶效果，在最前端啊，就是设置的z-index。。。
@lzhdim: 不知道是不是窗口设置的问题。。
https://files.cnblogs.com/files/blogs/784441/snow.js?t=1677246190