polished/lib/internalHelpers/_rgbToHsl.js

A lightweight toolset for writing styles in Javascript.

"use strict";

exports.__esModule = true;
exports["default"] = void 0;
function rgbToHsl(color) {
  // make sure rgb are contained in a set of [0, 255]
  var red = color.red / 255;
  var green = color.green / 255;
  var blue = color.blue / 255;
  var max = Math.max(red, green, blue);
  var min = Math.min(red, green, blue);
  var lightness = (max + min) / 2;
  if (max === min) {
    // achromatic
    if (color.alpha !== undefined) {
      return {
        hue: 0,
        saturation: 0,
        lightness: lightness,
        alpha: color.alpha
      };
    } else {
      return {
        hue: 0,
        saturation: 0,
        lightness: lightness
      };
    }
  }
  var hue;
  var delta = max - min;
  var saturation = lightness > 0.5 ? delta / (2 - max - min) : delta / (max + min);
  switch (max) {
    case red:
      hue = (green - blue) / delta + (green < blue ? 6 : 0);
      break;
    case green:
      hue = (blue - red) / delta + 2;
      break;
    default:
      // blue case
      hue = (red - green) / delta + 4;
      break;
  }
  hue *= 60;
  if (color.alpha !== undefined) {
    return {
      hue: hue,
      saturation: saturation,
      lightness: lightness,
      alpha: color.alpha
    };
  }
  return {
    hue: hue,
    saturation: saturation,
    lightness: lightness
  };
}
var _default = exports["default"] = rgbToHsl;
module.exports = exports.default;