console.log(0b1010 & 0b0010)

// 2

const hsl2rgb = (h, s, l, o) => {

  if (h > 1 || s > 1 || l > 1) {

      h /= 360;

      s /= 100;

      l /= 100;

  }

  h *= 360;

  let R, G, B, X, C;

  h = (h % 360) / 60;

  C = 2 * s * (l < .5 ? l : 1 - l);

  X = C * (1 - Math.abs(h % 2 - 1));

  R = G = B = l - C / 2;

  h = ~~h;

  R += [C, X, 0, 0, X, C][h];

  G += [X, C, C, X, 0, 0][h];

  B += [0, 0, X, C, C, X][h];

  return `rgba(${~~(R * 255)}, ${~~(G * 255)}, ${~~(B * 255)}, ${o})`;

};

console.log(hsl2rgb(122, 50, 50, .5));

const FOUR_PI = 4 * Math.PI;

const { cos, sin } = Math;

const canvas = document.body.appendChild(

  document.createElement('canvas')

);

const c = canvas.getContext('2d');

function resize() {

  canvas.width = window.innerWidth;

  canvas.height = window.innerHeight;

}

let inc = 0;

function draw() {

  c.clearRect(0, 0, canvas.width, canvas.height);

  c.fillStyle = 'blue';

  const halfWidth = window.innerWidth / 2;

  const halfHeight = window.innerHeight / 2;

  let theta = 0,

    a = 20 * Math.min(window.innerWidth, window.innerHeight) * 0.005,

    x,

    y;

  c.save();

  c.translate(halfWidth, halfHeight)

  // Freeth's Nephroid

  // https://mathshistory.st-andrews.ac.uk/Curves/Freeths/

  // r = a(1 + 2sin(θ / 2))

  let b = 2 * cos(inc);

  inc += .01;

  for (let i = 0; theta < FOUR_PI; i++) {

    let rad = a * (b + 2 * sin(theta / 2))

    x = rad * cos(theta);

    y = rad * sin(theta);

    c.fillRect(x, y, 2, 2);

    theta += 0.05;

  }

  c.restore();

  requestAnimationFrame(draw)

}

resize();

window.addEventListener('resize', resize);

draw()

const TWO_PI = Math.PI * 2;

const THREE_PI = 3 * Math.PI;

const canvas = document.body.appendChild(

  document.createElement('canvas')

);

const c = canvas.getContext('2d');

const halfWidth = (canvas.width = 250) / 2;

const halfHeight = (canvas.height = 250) / 2;

const scale = 10;

c.fillStyle = '#f0e195';

c.strokeStyle = '#c2a272';

c.beginPath();

for (let theta = 0; theta <= TWO_PI; theta += 0.02) {

  const x = (TWO_PI - Math.sin(theta)) * Math.cos(theta);

  const y = THREE_PI * Math.sin(theta);

  c.lineTo(halfWidth + x * scale, halfHeight - y * scale);

}

c.fill();

c.stroke();

const fs = require('fs');

function writeNextFile(file, content, files, done) {

  fs.writeFile(file, content + '\n', () => {

    const next = files.shift();

    if (!next && done != null) {

      done();

      return;

    }

    writeNextFile(next.file, next.content, files, done);

  });

}

function writeFiles(files, cb) {

  const curr = files.shift();

  writeNextFile(curr.file, curr.content, files, cb);

}

writeFiles(

  [

    {

      file: 'zevan1.txt',

      content: 'hello world'

    },

    {

      file: 'zevan2.txt',

      content: 'goodbye world'

    },

    {

      file: 'confusing.txt',

      content: 'greetings world'

    }

  ],

  () => {

    console.log('done');

  }

);