gistfile1.c

void rgb_to_hsv_doubles(double *out, double *in)
  34 {
  35         assert_rgb(in);
  36         double r, g, b, h, s, v, M, m;
  37         r = in[0]; g = in[1]; b = in[2];
  38 
  39         //printf("rgb %g,%g,%g...\n", r, g, b);
  40 
  41         if (g >= r && g >= b) {
  42                 M = g;
  43                 m = BAD_MIN(r, b);
  44                 h = M == m ? 0 : 60*(b-r)/(M-m)+120;
  45         }
  46         else if (b >= g && b >= r) {
  47                 M = b;
  48                 m = BAD_MIN(r, b);
  49                 h = M == m ? 0 : 60*(r-g)/(M-m)+240;
  50         }
  51         else {
  52                 assert(r >= g && r >= b);
  53                 M = r;
  54                 if (g >= b) {
  55                         m = b;
  56                         h = M == m ? 0 : 60*(g-b)/(M-m)+0;
  57                 } else {
  58                         m = g;
  59                         h = M == m ? 0 : 60*(g-b)/(M-m)+360;
  60                 }
  61         }
  62 
  63         s = M == 0 ? 0 : (M - m)/M;
  64         v = M;
  65         h = fmod(h, 360);
  66 
  67         //printf("\thsv %g,%g,%g\n", h, s, v);
  68         out[0] = h; out[1] = s; out[2] = v;
  69         assert_hsv(out);
  70 }
  71