Conversion algorithms for converting HSL to RGB and RGB to HSL vice versa in C

hsl2rgb_rgb2hsl.c

#include <stdio.h>

static void hueToRgb(unsigned int *c, float p, float q, float t) {
    if (t < 0.0f)
        t += 1.0f;
    if (t > 1.0f)
        t -= 1.0f;
    if (t < 0.166666)
        *c = (unsigned int) ((q + (p - q) * 6 * t) * 100);
    else if (t < 0.5)
        *c = (unsigned int) (p * 100);
    else if (t < 0.666666)
        *c = (unsigned int) ((q + (p - q) * (.666666 - t) * 6) * 100);
    else
        *c = (unsigned int) (q * 100);
}

/*
 * Converts an RGB color value to HSL.
 */
void RGBToHSL(unsigned int r, unsigned int g, unsigned int b, float hsl[]) {

    float red, green, blue;
    float max, min, delta;
    float H, S, L;

    red = (float) r / 255.0f;
    green = (float) g / 255.0f;
    blue = (float) b / 255.0f;

    max = red > (green > blue ? green : blue) ? red : green > blue ? green : blue;
    min = red < (green < blue ? green : blue) ? red : green < blue ? green : blue;

    H = S = L = 0;
    L = (max + min) / 2;

    if (max != min) {
        delta = max - min;

        S = delta / (L < .50 ? max + min : 2 - max - min);

        if (max == red) {
            H = (green - blue) / (delta);
        } else if (max == green) {
            H = 2 + (blue - red) / delta;
        } else if (max == blue) {
            H = 4 + (red - green) / delta;
        }
        H /= 6;
    }

    hsl[0] = H;
    hsl[1] = S;
    hsl[2] = L;
}

void HSLToRGB(float H, float S, float L, int rgb[]) {

    unsigned int red, green, blue;
    float p, q;

    if (S == 0) {
        red = green = blue = (unsigned int) (L * 100);
    } else {
        p = L < .50 ? L * (1 + S) : L + S - (L * S);
        q = 2 * L - p;


        hueToRgb(&red, p, q, H + .33333f);

        hueToRgb(&green, p, q, H);

        hueToRgb(&blue, p, q, H - .33333f);


    }
    red = (unsigned int) (((((float) red) / 100) * 255) + 0.5);
    green = (unsigned int) (((((float) green) / 100) * 255) + 0.5);
    blue = (unsigned int) (((((float) blue) / 100) * 255) + 0.5);

    rgb[0] = red;
    rgb[1] = green;
    rgb[2] = blue;
}

int main() {
    const int red = 0x80, green = 0x80, blue = 0x80;
    float hsl[3];
    int rgb[3];

    RGBToHSL(red, green, blue, hsl);

    printf("HSL(%f,%f,%f)\n", hsl[0], hsl[1], hsl[2]);

    HSLToRGB(hsl[0], hsl[1], hsl[2], rgb);

    printf("RGB(%d,%d,%d)\n", rgb[0], rgb[1], rgb[2]);
}