Massive changes to the organisation of PolyVoxCore and PolyVoxYtil.

Also added start of logging capability.

library/PolyVoxCore/source/PolyVoxImpl/Utility.cpp

@@ -0,0 +1,63 @@
+#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 "PolyVoxImpl/Utility.h"
+
+#include <cassert>
+#include <stdexcept>
+
+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.
+	uint8_t logBase2(uint32_t uInput)
+	{
+		//Debug mode validation
+		assert(uInput != 0);
+		assert(isPowerOf2(uInput));
+
+		//Release mode validation
+		if(uInput == 0)
+		{
+			throw std::invalid_argument("Cannot compute the log of zero.");
+		}
+		if(!isPowerOf2(uInput))
+		{
+			throw std::invalid_argument("Input must be a power of two in order to compute the log.");
+		}
+
+		uint32_t uResult = 0;
+		while( (uInput >> uResult) != 0)
+		{
+			++uResult;
+		}
+		return static_cast<uint8_t>(uResult-1);
+	}
+
+
+	bool isPowerOf2(uint32_t uInput)
+	{
+		if(uInput == 0)
+			return false;
+		else
+			return ((uInput & (uInput-1)) == 0);
+	}
+}