0028205: Visualization - add functionality for dumping results of detection algorithm...

[occt.git] / src / Quantity / Quantity_ColorHasher.hxx

diff --git a/src/Quantity/Quantity_ColorHasher.hxx b/src/Quantity/Quantity_ColorHasher.hxx
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+++ b/src/Quantity/Quantity_ColorHasher.hxx
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+// Created on: 2016-12-13
+// Copyright (c) 2016 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _Quantity_ColorHasher_HeaderFile
+#define _Quantity_ColorHasher_HeaderFile
+
+#include <Quantity_Color.hxx>
+
+//! Hasher of Quantity_Color.
+struct Quantity_ColorHasher
+{
+  //! Returns hash code for the given color.
+  static Standard_Integer HashCode (const Quantity_Color&  theColor,
+                                    const Standard_Integer theUpper)
+  {
+    Standard_Integer aRed   = Standard_Integer (255 * theColor.Red());
+    Standard_Integer aGreen = Standard_Integer (255 * theColor.Green());
+    Standard_Integer aBlue  = Standard_Integer (255 * theColor.Blue());
+
+    Standard_Integer aHash = 0;
+    updateHash (aHash, aRed);
+    updateHash (aHash, aGreen);
+    updateHash (aHash, aBlue);
+    aHash += (aHash << 3);
+    aHash ^= (aHash >> 11);
+    aHash += (aHash << 15);
+    return ((aHash & 0x7fff) % theUpper) + 1;
+  }
+
+  //! Returns true if two colors are equal.
+  static Standard_Boolean IsEqual (const Quantity_Color& theColor1,
+                                   const Quantity_Color& theColor2)
+  {
+    return theColor1 == theColor2;
+  }
+
+protected:
+  static void updateHash (Standard_Integer&      theHash,
+                          const Standard_Integer theValue)
+  {
+    theHash += theValue;
+    theHash += (theHash << 10);
+    theHash ^= (theHash >> 6);
+  }
+};
+
+#endif