NeoPixels.c

/*
 * NeoPixels.c
 *
 *  Created on: Aug 15, 2018
 *      Author: hunter
 */

#include "NeoPixels.h"


/*
 * h in range [0.0,360)
 * s in range [0.0,1.0]
 * v in range [0.0,1.0]
 */
rgb hsv2rgb(hsv in)
{
  double      hh, p, q, t, ff;
  long        i;
  rgb         out;

  if(in.s <= 0.0) {       // < is bogus, just shuts up warnings
      out.r = in.v;
      out.g = in.v;
      out.b = in.v;
      return out;
  }
  hh = in.h;
  if(hh >= 360.0)
    hh = 0.0;
  hh /= 60.0;
  i = (long)hh;
  ff = hh - i;
  p = in.v * (1.0 - in.s);
  q = in.v * (1.0 - (in.s * ff));
  t = in.v * (1.0 - (in.s * (1.0 - ff)));

  switch(i) {
  case 0:
      out.r = in.v;
      out.g = t;
      out.b = p;
      break;
  case 1:
      out.r = q;
      out.g = in.v;
      out.b = p;
      break;
  case 2:
      out.r = p;
      out.g = in.v;
      out.b = t;
      break;

  case 3:
      out.r = p;
      out.g = q;
      out.b = in.v;
      break;
  case 4:
      out.r = t;
      out.g = p;
      out.b = in.v;
      break;
  case 5:
  default:
      out.r = in.v;
      out.g = p;
      out.b = q;
      break;
  }

  return out;

}