Skip to content

Instantly share code, notes, and snippets.

@CodeMyUI
Last active Jul 28, 2020
Embed
What would you like to do?
Raining with Lightning
<html><head>
<title>Raining with Thunder</title>
</head><body onresize='_pexresize()'>
<canvas id='canvas' width='1280' height='720'></canvas>
</body></html>
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
var stgw = 1280;
var stgh = 720;
var loffset = 0;
var toffset = 0;
function _pexresize() {
var cw = window.innerWidth;
var ch = window.innerHeight;
if (cw<=ch*stgw/stgh) {
loffset = 0;
toffset = Math.floor(ch-(cw*stgh/stgw))/2;
canvas.style.width = cw + "px";
canvas.style.height = Math.floor(cw*stgh/stgw) + "px";
} else {
loffset = Math.floor(cw-(ch*stgw/stgh))/2;
toffset = 0;
canvas.style.height = ch + "px";
canvas.style.width = Math.floor(ch*stgw/stgh) + "px";
}
canvas.style.marginLeft = loffset +"px";
canvas.style.marginTop = toffset +"px";
}
_pexresize();
var count = 100;
var lcount = 6;
var layer = [];
var layery = [];
ctx.fillStyle = "rgba(255,255,255,0.5)";
for (var l=0;l<lcount;l++) {
ctx.clearRect(0,0,stgw,stgh);
for (var i=0;i<count*(lcount-l)/1.5;i++) {
var myx = Math.floor(Math.random()*stgw);
var myy = Math.floor(Math.random()*stgh);
var myh = l*6+8;
var myw = myh/10;
ctx.beginPath();
ctx.moveTo(myx,myy);
ctx.lineTo(myx+myw,myy+myh);
ctx.arc(myx, myy+myh, myw, 0, 1 * Math.PI);
ctx.lineTo(myx-myw,myy+myh);
ctx.closePath();
ctx.fill();
}
layer[l] = new Image();
layer[l].src = canvas.toDataURL("image/png");
layery[l] = 0;
}
var stt = 0;
var str = Date.now()+Math.random()*4000;
var stact = false;
function animate() {
ctx.clearRect(0,0,stgw,stgh);
for (var l=0;l<lcount;l++) {
layery[l] += (l+1.5)*5;
if (layery[l]>stgh) {
layery[l] =layery[l]-stgh;
}
ctx.drawImage(layer[l],0,layery[l]);
ctx.drawImage(layer[l],0,layery[l]-stgh);
}
if (Date.now()>str) {
stact = true;
}
if (stact) {
stt++;
if (stt<5+Math.random()*10) {
var ex = stt/30;
} else {
var ex = (stt-10)/30;
}
if (stt>20) {
stt = 0;
stact = false;
str = Date.now()+Math.random()*8000+2000;
}
ctx.fillStyle = "rgba(255,255,255,"+ex+")";
ctx.fillRect(0,0,stgw,stgh);
}
window.requestAnimationFrame(animate);
}
animate();
body {
margin:0;
background: #000;
}
canvas {
background:url('https://i.postimg.cc/6q3KG8Hw/maxresdefault.jpg');
background-size: cover;
background-repeat: no-repeat;
background-position: center center;
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment