00001 /* 00002 ----------------------------------------------------------------------------- 00003 This source file is part of OGRE 00004 (Object-oriented Graphics Rendering Engine) 00005 For the latest info, see http://www.ogre3d.org/ 00006 00007 Copyright © 2000-2002 The OGRE Team 00008 Also see acknowledgements in Readme.html 00009 00010 This program is free software; you can redistribute it and/or modify it under 00011 the terms of the GNU Lesser General Public License as published by the Free Software 00012 Foundation; either version 2 of the License, or (at your option) any later 00013 version. 00014 00015 This program is distributed in the hope that it will be useful, but WITHOUT 00016 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 00017 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. 00018 00019 You should have received a copy of the GNU Lesser General Public License along with 00020 this program; if not, write to the Free Software Foundation, Inc., 59 Temple 00021 Place - Suite 330, Boston, MA 02111-1307, USA, or go to 00022 http://www.gnu.org/copyleft/lesser.txt. 00023 ----------------------------------------------------------------------------- 00024 */ 00025 #ifndef _Bitwise_H__ 00026 #define _Bitwise_H__ 00027 00028 #include "OgrePrerequisites.h" 00029 00030 namespace Ogre { 00031 00034 class Bitwise { 00035 public: 00039 template<typename T> 00040 static FORCEINLINE unsigned int getBitShift(T mask) 00041 { 00042 if (mask == 0) 00043 return 0; 00044 00045 unsigned int result = 0; 00046 while ((mask & 1) == 0) { 00047 ++result; 00048 mask >>= 1; 00049 } 00050 return result; 00051 } 00052 00058 template<typename SrcT, typename DestT> 00059 static inline DestT convertBitPattern(SrcT srcValue, SrcT srcBitMask, DestT destBitMask) 00060 { 00061 // Mask off irrelevant source value bits (if any) 00062 srcValue = srcValue & srcBitMask; 00063 00064 // Shift source down to bottom of DWORD 00065 const unsigned int srcBitShift = getBitShift(srcBitMask); 00066 srcValue >>= srcBitShift; 00067 00068 // Get max value possible in source from srcMask 00069 const SrcT srcMax = srcBitMask >> srcBitShift; 00070 00071 // Get max avaiable in dest 00072 const unsigned int destBitShift = getBitShift(destBitMask); 00073 const DestT destMax = destBitMask >> destBitShift; 00074 00075 // Scale source value into destination, and shift back 00076 DestT destValue = (srcValue * destMax) / srcMax; 00077 return (destValue << destBitShift); 00078 } 00079 }; 00080 } 00081 00082 #endif
Copyright © 2002-2003 by The OGRE Team
Last modified Fri May 14 23:21:53 2004