kasa-smart-hub/lib/util/colors/rgb-to-hsb.js

Virtual Smart Hub for TP-Link Kasa Smart Home

export default (r, g, b) => {
  const max = Math.max(r, g, b);
  const min = Math.min(r, g, b);
  const delta = max - min;

  // hue
  let h;
  if (delta === 0) {
    h = 0;
  } else if (r === max) {
    h = ((g - b) / delta) % 6;
  } else if (g === max) {
    h = (b - r) / delta + 2;
  } else if (b === max) {
    h = (r - g) / delta + 4;
  }
  h = Math.round(h * 60);
  if (h < 0) {
    h += 360;
  }
  // saturation
  const s = Math.round((max === 0 ? 0 : (delta / max)) * 100);
  // value
  const v = Math.round((max / 255) * 100);

  return [h, s, v];
};