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+// io-hub - Modular Input/Output. {{{
+//
+// Copyright (C) 2013 Maxime Hadjinlian
+//
+// APBTeam:
+// Web: http://apbteam.org/
+// Email: team AT apbteam DOT org
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+//
+// }}}
+#include "rgb.hh"
+
+int
+Rgb::rgb_to_hue (int r, int g, int b)
+{
+ uint8_t min = 255, max = 0, hue;
+
+ // find minimal between r, g and b
+ if (r < min)
+ min = r;
+ if (g < min)
+ min = g;
+ if (b < min)
+ min = b;
+
+ // find maximal between r, g and b
+ if (r > max)
+ max = r;
+ if (g > max)
+ max = g;
+ if (b > max)
+ max = b;
+
+ if (min == max)
+ return 0;
+
+ /* Compute hue */
+ if (max == r)
+ hue = 0 + 43 * (g - b) / (max - min);
+ else if (max == g)
+ hue = 85 + 43 * (b - r) / (max - min);
+ else /* max == b */
+ hue = 171 + 43 * (r - g) / (max - min);
+ return hue;
+}