tempToHSL.js

const numChecker = (num, min, max) => (num < min ? min : num > max ? max : num);

const rgb2hsv = (r, g, b) => {
    let rabs, gabs, babs, rr, gg, bb, h, s, v, diff, diffc, percentRoundFn;
    rabs = r / 255;
    gabs = g / 255;
    babs = b / 255;
    (v = Math.max(rabs, gabs, babs)), (diff = v - Math.min(rabs, gabs, babs));
    diffc = (c) => (v - c) / 6 / diff + 1 / 2;
    percentRoundFn = (num) => Math.round(num * 100) / 100;
    if (diff == 0) {
        h = s = 0;
    } else {
        s = diff / v;
        rr = diffc(rabs);
        gg = diffc(gabs);
        bb = diffc(babs);

        if (rabs === v) {
            h = bb - gg;
        } else if (gabs === v) {
            h = 1 / 3 + rr - bb;
        } else if (babs === v) {
            h = 2 / 3 + gg - rr;
        }
        if (h < 0) {
            h += 1;
        } else if (h > 1) {
            h -= 1;
        }
    }
    return {
        h: Math.round(h * 360),
        s: percentRoundFn(s * 100),
        v: percentRoundFn(v * 100),
    };
};

const tempToHSL = (tmpKelvin) => {
    tmpKelvin = numChecker(tmpKelvin, 1000, 40000) / 100;

    const hash = {
        r:
            tmpKelvin <= 66
                ? 255
                : Math.round(
                      numChecker(
                          329.698727446 *
                              Math.pow(tmpKelvin - 60, -0.1332047592),
                          0,
                          255
                      )
                  ),

        g:
            tmpKelvin <= 66
                ? Math.round(
                      numChecker(
                          99.4708025861 * Math.log(tmpKelvin) - 161.1195681661,
                          0,
                          255
                      )
                  )
                : Math.round(
                      numChecker(
                          288.1221695283 *
                              Math.pow(tmpKelvin - 60, -0.0755148492),
                          0,
                          255
                      )
                  ),

        b:
            tmpKelvin >= 66
                ? 255
                : tmpKelvin <= 19
                ? 0
                : Math.round(
                      numChecker(
                          138.5177312231 * Math.log(tmpKelvin - 10) -
                              305.0447927307,
                          0,
                          255
                      )
                  ),
    };
    return rgb2hsv(hash.r, hash.g, hash.b);
};