hsla-rgba.ts

import { clamp01 } from "@thi.ng/math";
import { setC3 } from "@thi.ng/vectors";
import type { ColorOp } from "./api";
import { hueRgba } from "./hue-rgba";
import { ensureAlpha } from "./internal/ensure-alpha";

export const hslaRgba: ColorOp = (out, src) => {
    const s = clamp01(src[1]);
    const l = clamp01(src[2]);
    out = hueRgba(out || src, src[0], ensureAlpha(src[3]));
    const c = (1 - Math.abs(2 * l - 1)) * s;
    return setC3(
        out,
        (out[0] - 0.5) * c + l,
        (out[1] - 0.5) * c + l,
        (out[2] - 0.5) * c + l
    );
};