culori/src/hwb/convertHwbToRgb.js

A general-purpose color library for JavaScript

/*
	HWB to RGB converter
	--------------------

	References:
		* https://drafts.csswg.org/css-color/#hwb-to-rgb
		* https://en.wikipedia.org/wiki/HWB_color_model
		* http://alvyray.com/Papers/CG/HWB_JGTv208.pdf
 */

import convertHsvToRgb from '../hsv/convertHsvToRgb.js';

export default function convertHwbToRgb({ h, w, b, alpha }) {
	if (w === undefined) w = 0;
	if (b === undefined) b = 0;
	// normalize w + b to 1
	if (w + b > 1) {
		let s = w + b;
		w /= s;
		b /= s;
	}
	return convertHsvToRgb({
		h: h,
		s: b === 1 ? 1 : 1 - w / (1 - b),
		v: 1 - b,
		alpha: alpha
	});
}