Javascript 使用HTML5和JS创建雪花
我参观了公园,我喜欢下雪!我的问题是,我如何才能重现一个类似的效果,看起来也一样好。我试图对代码进行反向工程,看看是否能找到它,但遗憾的是,没有运气。JS在我头上。我在谷歌上搜索了一下,发现了一些,但它们没有SE网站那么优雅,或者看起来不太好 有没有人能提供一些关于如何复制SE Winter Bash站点创建的内容的说明,或者提供一个我可以学习如何进行复制的地方Javascript 使用HTML5和JS创建雪花,javascript,html,canvas,Javascript,Html,Canvas,我参观了公园,我喜欢下雪!我的问题是,我如何才能重现一个类似的效果,看起来也一样好。我试图对代码进行反向工程,看看是否能找到它,但遗憾的是,没有运气。JS在我头上。我在谷歌上搜索了一下,发现了一些,但它们没有SE网站那么优雅,或者看起来不太好 有没有人能提供一些关于如何复制SE Winter Bash站点创建的内容的说明,或者提供一个我可以学习如何进行复制的地方 编辑:我希望尽可能近距离地复制效果,即:雪花飘落,能够移动鼠标并使雪随着鼠标移动或旋转 降雪很简单:创建画布,创建一束雪花,然后绘制它
编辑:我希望尽可能近距离地复制效果,即:雪花飘落,能够移动鼠标并使雪随着鼠标移动或旋转 降雪很简单:创建画布,创建一束雪花,然后绘制它们 您可以这样创建雪花类:
function Snowflake() {
this.x = Math.random()*canvas.width;
this.y = -16;
this.speed = Math.random()*3+1;
this.direction = Math.random()*360;
this.maxSpeed = 4;
}
或者类似的。然后,你有一个计时器,每一步,调整每个雪花的方向一小部分,然后计算其新的X和Y的因素在速度和方向
这很难解释,但实际上非常基本。很好的问题,我不久前写了一个snow插件,我不断更新它 我注意到你给问题html5和canvas加了标签,但是你可以不使用它们,只使用带有图像或不同背景颜色的标准元素 这里有两个非常简单的问题,我刚才把它们放在一起,让你来处理。在我看来,关键是使用sin在雪花落下时获得良好的波浪效果。第一个使用canvas元素,第二个使用常规dom元素 因为我完全沉迷于画布,在我看来,这是一个画布版本,它的表现相当不错
(function() {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
window.requestAnimationFrame = requestAnimationFrame;
})();
var flakes = [],
canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d"),
flakeCount = 200,
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,
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 + ")";
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;
flake.speed = (Math.random() * 1) + 0.5;
flake.velY = flake.speed;
flake.velX = 0;
flake.opacity = (Math.random() * 0.5) + 0.3;
}
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,
speed = (Math.random() * 1) + 0.5,
opacity = (Math.random() * 0.5) + 0.3;
flakes.push({
speed: speed,
velY: speed,
velX: 0,
x: x,
y: y,
size: size,
stepSize: (Math.random()) / 30,
step: 0,
angle: 180,
opacity: opacity
});
}
snow();
};
canvas.addEventListener("mousemove", function(e) {
mX = e.clientX,
mY = e.clientY
});
init();
var flakes = [],
bodyHeight = getDocHeight(),
bodyWidth = document.body.offsetWidth;
function snow() {
for (var i = 0; i < 50; i++) {
var flake = flakes[i];
flake.y += flake.velY;
if (flake.y > bodyHeight - (flake.size + 6)) {
flake.y = 0;
}
flake.el.style.top = flake.y + 'px';
flake.el.style.left = ~~flake.x + 'px';
flake.step += flake.stepSize;
flake.velX = Math.cos(flake.step);
flake.x += flake.velX;
if (flake.x > bodyWidth - 40 || flake.x < 30) {
flake.y = 0;
}
}
setTimeout(snow, 10);
};
function init() {
var docFrag = document.createDocumentFragment();
for (var i = 0; i < 50; i++) {
var flake = document.createElement("div"),
x = Math.floor(Math.random() * bodyWidth),
y = Math.floor(Math.random() * bodyHeight),
size = (Math.random() * 5) + 2,
speed = (Math.random() * 1) + 0.5;
flake.style.width = size + 'px';
flake.style.height = size + 'px';
flake.style.background = "#fff";
flake.style.left = x + 'px';
flake.style.top = y;
flake.classList.add("flake");
flakes.push({
el: flake,
speed: speed,
velY: speed,
velX: 0,
x: x,
y: y,
size: 2,
stepSize: (Math.random() * 5) / 100,
step: 0
});
docFrag.appendChild(flake);
}
document.body.appendChild(docFrag);
snow();
};
document.addEventListener("mousemove", function(e) {
var x = e.clientX,
y = e.clientY,
minDist = 150;
for (var i = 0; i < flakes.length; i++) {
var x2 = flakes[i].x,
y2 = flakes[i].y;
var dist = Math.sqrt((x2 - x) * (x2 - x) + (y2 - y) * (y2 - y));
if (dist < minDist) {
rad = Math.atan2(y2, x2), angle = rad / Math.PI * 180;
flakes[i].velX = (x2 / dist) * 0.2;
flakes[i].velY = (y2 / dist) * 0.2;
flakes[i].x += flakes[i].velX;
flakes[i].y += flakes[i].velY;
} else {
flakes[i].velY *= 0.9;
flakes[i].velX
if (flakes[i].velY <= flakes[i].speed) {
flakes[i].velY = flakes[i].speed;
}
}
}
});
init();
function getDocHeight() {
return Math.max(
Math.max(document.body.scrollHeight, document.documentElement.scrollHeight), Math.max(document.body.offsetHeight, document.documentElement.offsetHeight), Math.max(document.body.clientHeight, document.documentElement.clientHeight));
}
(function() {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
window.requestAnimationFrame = requestAnimationFrame;
})();
var flakes = [],
canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d"),
flakeCount = 200,
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,
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 + ")";
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;
flake.speed = (Math.random() * 1) + 0.5;
flake.velY = flake.speed;
flake.velX = 0;
flake.opacity = (Math.random() * 0.5) + 0.3;
}
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,
speed = (Math.random() * 1) + 0.5,
opacity = (Math.random() * 0.5) + 0.3;
flakes.push({
speed: speed,
velY: speed,
velX: 0,
x: x,
y: y,
size: size,
stepSize: (Math.random()) / 30,
step: 0,
angle: 180,
opacity: opacity
});
}
snow();
};
canvas.addEventListener("mousemove", function(e) {
mX = e.clientX,
mY = e.clientY
});
init();
var flakes = [],
bodyHeight = getDocHeight(),
bodyWidth = document.body.offsetWidth;
function snow() {
for (var i = 0; i < 50; i++) {
var flake = flakes[i];
flake.y += flake.velY;
if (flake.y > bodyHeight - (flake.size + 6)) {
flake.y = 0;
}
flake.el.style.top = flake.y + 'px';
flake.el.style.left = ~~flake.x + 'px';
flake.step += flake.stepSize;
flake.velX = Math.cos(flake.step);
flake.x += flake.velX;
if (flake.x > bodyWidth - 40 || flake.x < 30) {
flake.y = 0;
}
}
setTimeout(snow, 10);
};
function init() {
var docFrag = document.createDocumentFragment();
for (var i = 0; i < 50; i++) {
var flake = document.createElement("div"),
x = Math.floor(Math.random() * bodyWidth),
y = Math.floor(Math.random() * bodyHeight),
size = (Math.random() * 5) + 2,
speed = (Math.random() * 1) + 0.5;
flake.style.width = size + 'px';
flake.style.height = size + 'px';
flake.style.background = "#fff";
flake.style.left = x + 'px';
flake.style.top = y;
flake.classList.add("flake");
flakes.push({
el: flake,
speed: speed,
velY: speed,
velX: 0,
x: x,
y: y,
size: 2,
stepSize: (Math.random() * 5) / 100,
step: 0
});
docFrag.appendChild(flake);
}
document.body.appendChild(docFrag);
snow();
};
document.addEventListener("mousemove", function(e) {
var x = e.clientX,
y = e.clientY,
minDist = 150;
for (var i = 0; i < flakes.length; i++) {
var x2 = flakes[i].x,
y2 = flakes[i].y;
var dist = Math.sqrt((x2 - x) * (x2 - x) + (y2 - y) * (y2 - y));
if (dist < minDist) {
rad = Math.atan2(y2, x2), angle = rad / Math.PI * 180;
flakes[i].velX = (x2 / dist) * 0.2;
flakes[i].velY = (y2 / dist) * 0.2;
flakes[i].x += flakes[i].velX;
flakes[i].y += flakes[i].velY;
} else {
flakes[i].velY *= 0.9;
flakes[i].velX
if (flakes[i].velY <= flakes[i].speed) {
flakes[i].velY = flakes[i].speed;
}
}
}
});
init();
function getDocHeight() {
return Math.max(
Math.max(document.body.scrollHeight, document.documentElement.scrollHeight), Math.max(document.body.offsetHeight, document.documentElement.offsetHeight), Math.max(document.body.clientHeight, document.documentElement.clientHeight));
}
(函数(){
var requestAnimationFrame=window.requestAnimationFrame | | window.mozRequestAnimationFrame | | window.webkitRequestAnimationFrame | | window.msRequestAnimationFrame||
函数(回调){
设置超时(回调,1000/60);
};
window.requestAnimationFrame=requestAnimationFrame;
})();
var flakes=[],
canvas=document.getElementById(“canvas”),
ctx=canvas.getContext(“2d”),
片数=200,
mX=-100,
mY=-100
canvas.width=window.innerWidth;
canvas.height=window.innerHeight;
函数snow(){
clearRect(0,0,canvas.width,canvas.height);
对于(变量i=0;i车身宽度-40 | |片状x<30){
薄片y=0;
}
}
设置超时(雪,10);
};
函数init(){
var docFrag=document.createDocumentFragment();
对于(变量i=0;i<50;i++){
var flake=document.createElement(“div”),
x=数学地板(数学随机()*车身宽度),
y=数学地板(数学随机()*车身高度),
大小=(Math.random()*5)+2,
速度=(Math.random()*1)+0.5;
flake.style.width=尺寸+px;
flake.style.height=尺寸+px;
flake.style.background=“#fff”;
flake.style.left=x+'px';
flake.style.top=y;
flake.classList.add(“flake”);
推({
艾尔:弗莱克,
速度:速度,,
速度,,
velX:0,
x:x,
y:y,
尺寸:2,
步长:(Math.random()*5)/100,
步骤:0
});
文件附件(薄片);
}
文件.正文.附件(docFrag);
雪();
};
文档.添加的事件列表器(“mousemove”,函数(e){
var x=e.clientX,
y=e.clientY,
正念派=150;
对于(变量i=0;i 如果(flakes[i].velY看起来像是在接受错误的答案:P@j08691-继续并发布他们是如何做到的。如果你想添加一些提示和一些自己动手的想法,就去做吧。=>@Bergi-我说我从其他代码中剔除了snow代码,但我从来没有说过我能理解它或缩小它。这可能需要几天时间!)@j08691:将其作为wiki答案发布,让我们看看我们能做些什么:-)仅供参考,我计划将winterba.sh snow发布为开源。我会在发布后更新。谢谢您提供的信息!不过小提琴中没有降雪!我看到雪花在顶部移动,但没有降雪。真的吗?您使用的浏览器是什么?它在Chrome中工作,尽管我没有与任何其他浏览器进行测试。嘿,它正在下雪!现在您可以使用吗雪落下来,形成了一个雪人?…哈,