HSV to RGB

hsv2rgb.c

#include <math.h>

void hsv2rgb(float h, float s, float v, float *rgb) {
    float c = v * s;
    float hh = h * 6.0;
    float x = c * (1.0 - fabsf(fmodf(hh, 2) - 1.));
    float m = v - c;

    int i = (int)hh % 6;
    rgb[(1 + 2*i)%3] = x + m;
    rgb[((i+1)/2)%3] = c + m;
    rgb[(2+(i/2))%3] = 0.0 + m;
}

#include <stdio.h>

int main() {
    int steps = 24;

    for(int i = 0; i <= steps; ++i) {
        float h = i / (float)steps;
        float rgb[3];

        hsv2rgb(h, 1.0, 1.0, rgb);

        printf("%d\t%2.2f\t%2.2f\t%2.2f\n", i*(360/steps), rgb[0], rgb[1], rgb[2]);
    }
}