soccer-jersey-fixed/lib/utils/lighten-darken-color.js

Generate soccer jerseys in SVG format. Fork of the original soccer-jersey package, so that @svgdotjs/svg.js dependency is retrieved from npmjs rather than github

/**
 * Lighten or Darken a color
 * @param {string} color HEX color value
 * @param {number} amount Amount of color shift.
 *  For example a value of -10 to darken or 10 to lighten
 * @return {string} a HEX color string
 */
const lightenDarkenColor = (color, amount) => {
    color = color.replace(/^#/, '');
    if (color.length === 3) {
        color = color[0] + color[0] + color[1] + color[1] + color[2] + color[2];
    }
    const letterMatch = color.match(/.{2}/g);
    if (!letterMatch) {
        return color;
    }
    const [or, og, ob] = letterMatch;
    const [pr, pg, pb] = [
        parseInt(or, 16) + amount,
        parseInt(og, 16) + amount,
        parseInt(ob, 16) + amount,
    ];
    const r = Math.max(Math.min(255, pr), 0).toString(16);
    const g = Math.max(Math.min(255, pg), 0).toString(16);
    const b = Math.max(Math.min(255, pb), 0).toString(16);
    const rr = (r.length < 2 ? '0' : '') + r;
    const gg = (g.length < 2 ? '0' : '') + g;
    const bb = (b.length < 2 ? '0' : '') + b;
    return `#${rr}${gg}${bb}`;
};
export default lightenDarkenColor;