pure-color/convert/hsl2rgb.js

Pure functions for color conversion and parsing

function hsl2rgb(hsl) {
  var h = hsl[0] / 360,
      s = hsl[1] / 100,
      l = hsl[2] / 100,
      t1, t2, t3, rgb, val;

  if (s == 0) {
    val = l * 255;
    return [val, val, val];
  }

  if (l < 0.5)
    t2 = l * (1 + s);
  else
    t2 = l + s - l * s;
  t1 = 2 * l - t2;

  rgb = [0, 0, 0];
  for (var i = 0; i < 3; i++) {
    t3 = h + 1 / 3 * - (i - 1);
    t3 < 0 && t3++;
    t3 > 1 && t3--;

    if (6 * t3 < 1)
      val = t1 + (t2 - t1) * 6 * t3;
    else if (2 * t3 < 1)
      val = t2;
    else if (3 * t3 < 2)
      val = t1 + (t2 - t1) * (2 / 3 - t3) * 6;
    else
      val = t1;

    rgb[i] = val * 255;
  }

  return rgb;
}

module.exports = hsl2rgb;