LCH(uv)

import { registerColorFunction } from "saturon/utils";

/**
 * @see {@link http://www.brucelindbloom.com/index.html?Eqn_LCH_to_Luv.html|LCH(uv) to Luv}
 * @see {@link http://www.brucelindbloom.com/index.html?Eqn_Luv_to_LCH.html|Luv to LCH(uv)}
 */
registerColorFunction("lchuv", {
    components: {
        l: { index: 0, value: "percentage", precision: 5 },
        c: { index: 1, value: "percentage", precision: 5 },
        h: { index: 2, value: "angle", precision: 5 },
    },
    targetGamut: null,
    bridge: "luv",
    toBridge: ([L, C, H]) => {
        const hRad = (H * Math.PI) / 180;
        const u = C * Math.cos(hRad);
        const v = C * Math.sin(hRad);
        return [L, u, v];
    },
    fromBridge: ([L, u, v]) => {
        const C = Math.sqrt(u * u + v * v);
        let H = Math.atan2(v, u) * (180 / Math.PI);
        if (H < 0) H += 360;
        return [L, C, H];
    },
});