JavaScript preprocessors can help make authoring JavaScript easier and more convenient. For instance, CoffeeScript can help prevent easy-to-make mistakes and offer a cleaner syntax and Babel can bring ECMAScript 6 features to browsers that only support ECMAScript 5.

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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

` ````
<canvas id=c></canvas>
```

` ````
canvas {
position: absolute;
top: 0;
left: 0;
}
```

` ````
let w = c.width = window.innerWidth;
let h = c.height = window.innerHeight;
const ctx = c.getContext('2d');
const opts = {
hexLength: 30,
lenFn: ({ len, t }) =>
len + Math.sin(t),
radFn: ({ rad, len, t, excitement }) =>
rad + (excitement + opts.propFn({ len, t }))*2 / 4,
propFn: ({ len, t }) =>
len / opts.hexLength / 10 - t,
excitementFn: ({ len, t }) =>
Math.sin(opts.propFn({ len, t }))**2,
colorFn: ({ rad, excitement, t }) =>
`hsl(${rad / Math.TAU * 360 + t}, ${excitement * 100}%, ${20 + excitement * 50}%)`,
timeStep: .01,
randomJig: 8,
repaintColor: 'rgba(0,0,0,.1)'
};
let tick = 0;
Math.TAU = 6.28318530717958647692;
const vertices = [];
class Vertex {
constructor({ x, y }) {
this.len = Math.sqrt(x*x + y*y);
this.rad = Math.acos(x / this.len) * (y > 0 ? 1 : -1) + .13;
this.prevPoint = { x, y };
}
step() {
const excitement = opts.excitementFn({ len: this.len, t: tick });
const param = {
len: this.len,
rad: this.rad,
t: tick,
excitement
};
const nextLen = opts.lenFn(param);
const nextRad = opts.radFn(param);
const color = opts.colorFn(param);
ctx.strokeStyle = color;
ctx.lineWidth = excitement + .2;
ctx.beginPath();
ctx.moveTo(this.prevPoint.x, this.prevPoint.y);
this.prevPoint.x = nextLen * Math.cos(nextRad) +
Math.random() * (1-excitement)**2 * opts.randomJig * 2 - opts.randomJig;
this.prevPoint.y = nextLen * Math.sin(nextRad) +
Math.random() * (1-excitement)**2 * opts.randomJig * 2 - opts.randomJig;
ctx.lineTo(this.prevPoint.x, this.prevPoint.y);
ctx.stroke();
}
static gen() {
vertices.length = 0;
const hexCos = Math.cos(Math.TAU / 12) * opts.hexLength;
const hexSin = Math.sin(Math.TAU / 12) * opts.hexLength;
let alternanceX = false;
for(let x = 0; x < w; x += hexCos) {
let alternance = alternanceX = !alternanceX;
for(let y = 0; y < h; y += hexSin + opts.hexLength) {
alternance = !alternance;
vertices.push(new Vertex({
x: x - w / 2,
y: y + alternance * hexSin - h / 2
}))
}
}
}
}
Vertex.gen();
ctx.fillStyle = '#222';
ctx.fillRect(0, 0, w, h);
const anim = () => {
window.requestAnimationFrame(anim);
tick += opts.timeStep;
ctx.fillStyle = opts.repaintColor;
ctx.fillRect(0, 0, w, h);
ctx.translate(w/2, h/2);
vertices.forEach((vertex) => vertex.step());
ctx.translate(-w/2, -h/2);
}
anim();
window.addEventListener('resize', () => {
w = c.width = window.innerWidth;
h = c.height = window.innerHeight;
Vertex.gen();
tick = 0;
ctx.fillStyle = '#222';
ctx.fillRect(0, 0, w, h);
})
```

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