pex-color
Version:
Color utilities (css, p3, hex, hsl, hsv, hwb, lab, lch, xyz, okhsl, okhsv, oklab, oklch, hpluv, hsluv, lchuv, bytes) for PEX.
58 lines (48 loc) • 1.45 kB
JavaScript
/**
* @typedef {string} hex hexadecimal string (RGB[A] or RRGGBB[AA]).
*/
/**
* Updates a color based on a hexadecimal string.
* @alias module:pex-color.fromHex
* @param {import("./color.js").color} color
* @param {hex} hex Leading '#' is optional.
* @returns {import("./color.js").color}
*/
export function fromHex(color, hex) {
hex = hex.replace(/^#/, "");
let a = 1;
if (hex.length === 8) {
a = parseInt(hex.slice(6, 8), 16) / 255;
hex = hex.slice(0, 6);
} else if (hex.length === 4) {
a = parseInt(hex.slice(3, 4).repeat(2), 16) / 255;
hex = hex.slice(0, 3);
}
if (hex.length === 3) {
hex = hex[0] + hex[0] + hex[1] + hex[1] + hex[2] + hex[2];
}
const num = parseInt(hex, 16);
color[0] = ((num >> 16) & 255) / 255;
color[1] = ((num >> 8) & 255) / 255;
color[2] = (num & 255) / 255;
if (color[3] !== undefined) color[3] = a;
return color;
}
/**
* Returns a hexadecimal string representation of a given color.
* @alias module:pex-color.toHex
* @param {import("./color.js").color} color
* @param {boolean} alpha Handle alpha
* @returns {hex}
*/
export function toHex(color, alpha = true) {
const c = color.map((val) => Math.round(val * 255));
return `#${(c[2] | (c[1] << 8) | (c[0] << 16) | (1 << 24))
.toString(16)
.slice(1)
.toUpperCase()}${
alpha && color[3] !== undefined && color[3] !== 1
? (c[3] | (1 << 8)).toString(16).slice(1)
: ""
}`;
}