@kcuf/mere-color/dist/cjs/util/compute-contrast.js

Mere color utils for generating, manipulation, a11y purposes.

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault").default;
Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = computeContrast;
var _round2 = _interopRequireDefault(require("lodash/round"));
/**
 * Compute contrast according to two luminance values.
 */
function computeContrast(fgcLuminance, bgcLuminance) {
  if (fgcLuminance < 0 || bgcLuminance < 0) {
    return -1;
  }
  return (0, _round2.default)(fgcLuminance > bgcLuminance ? (fgcLuminance + 0.05) / (bgcLuminance + 0.05) : (bgcLuminance + 0.05) / (fgcLuminance + 0.05), 3);
}