MyGUI  3.2.0
MyGUI_Bitwise.h
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00001 
00006 /*
00007     This file is part of MyGUI.
00008 
00009     MyGUI is free software: you can redistribute it and/or modify
00010     it under the terms of the GNU Lesser General Public License as published by
00011     the Free Software Foundation, either version 3 of the License, or
00012     (at your option) any later version.
00013 
00014     MyGUI is distributed in the hope that it will be useful,
00015     but WITHOUT ANY WARRANTY; without even the implied warranty of
00016     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00017     GNU Lesser General Public License for more details.
00018 
00019     You should have received a copy of the GNU Lesser General Public License
00020     along with MyGUI.  If not, see <http://www.gnu.org/licenses/>.
00021 */
00022 #ifndef __MYGUI_BITWISE_H__
00023 #define __MYGUI_BITWISE_H__
00024 
00025 #include "MyGUI_Prerequest.h"
00026 
00027 namespace MyGUI
00028 {
00029 
00030     class Bitwise
00031     {
00032     public:
00035         template<typename Type>
00036         static MYGUI_FORCEINLINE Type firstPO2From(Type _value)
00037         {
00038             --_value;
00039             _value |= _value >> 16;
00040             _value |= _value >> 8;
00041             _value |= _value >> 4;
00042             _value |= _value >> 2;
00043             _value |= _value >> 1;
00044             ++_value;
00045             return _value;
00046         }
00047 
00049         template<typename Type>
00050         static MYGUI_FORCEINLINE bool isPO2(Type _value)
00051         {
00052             return (_value & (_value - 1)) == 0;
00053         }
00054 
00058         template<typename Type>
00059         static MYGUI_FORCEINLINE size_t getBitShift(Type _mask)
00060         {
00061             if (_mask == 0)
00062                 return 0;
00063 
00064             size_t result = 0;
00065             while ((_mask & 1) == 0)
00066             {
00067                 ++result;
00068                 _mask >>= 1;
00069             }
00070             return result;
00071         }
00072     };
00073 
00074 } // namespace MyGUI
00075 
00076 #endif // __MYGUI_BITWISE_H__