/*
 * input: 
 * 0 <= h <= 360    (hue)
 * 0 <= v <= 1.0    (brightness)
 * 0 <= s <= 1.0    (saturation)
 *
 * output: 0 <= ir,ig,ib <= 255
 */
#include <math.h>

void hsvrgb(float h, float s, float v, int *ir, int *ig, int *ib)

{
  float pqvt[4], f;
  int i, irpnt[6]={2,1,0,0,3,2}, igpnt[6]={3,2,2,1,0,0},
         ibpnt[6]={0,0,3,2,2,1};
  if (s == 0.0) {
    *ir = 255.0*v;
    *ig = *ir;
    *ib = *ir;
    return;
  }
  if (h == 360.0) h=0.0;
  h = h / 60.0;
  i = floor(h);
  f = h-i;
  pqvt[2] = 255.0*v;
  pqvt[0] = pqvt[2]*(1.0-s);
  pqvt[1] = pqvt[2]*(1.0-s*f);
  pqvt[3] = pqvt[2]*(1.0-s*(1.0-f));
  *ir = pqvt[irpnt[i]];
  *ig = pqvt[igpnt[i]];
  *ib = pqvt[ibpnt[i]];
  return;
}