Moving stuff around - not currently buildable!

PolyVoxCore/source/Utility.cpp

@@ -0,0 +1,59 @@
+#pragma region License
+/******************************************************************************
+This file is part of the PolyVox library
+Copyright (C) 2006  David Williams
+
+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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+******************************************************************************/
+#pragma endregion
+
+#include "Utility.h"
+
+#include <cassert>
+
+namespace PolyVox
+{
+	//Note: this function only works for inputs which are a power of two and not zero
+	//If this is not the case then the output is undefined.
+	boost::uint8_t logBase2(boost::uint32_t uInput)
+	{
+		assert(uInput != 0);
+		assert(isPowerOf2(uInput));
+
+		boost::uint8_t result = 0;
+		uInput = uInput >> 1;
+		while(uInput)
+		{
+			uInput = uInput >> 1;
+			++result;
+		}
+		return result;
+	}
+
+	bool isPowerOf2(boost::uint32_t uInput)
+	{
+		boost::uint8_t uNonZeroBits = 0;
+		boost::uint32_t uMask = 0x00000001;
+		for(boost::uint8_t ct = 0; ct < 32; ++ct)
+		{
+			if(uInput & uMask)
+			{
+				++uNonZeroBits;
+			}
+			uMask = uMask << 1;
+		}
+		return uNonZeroBits == 1 ? true : false;
+	}
+}