77 lines
1.7 KiB
C++
77 lines
1.7 KiB
C++
/*!
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@file
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@author Albert Semenov
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@date 06/2009
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*/
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/*
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This file is part of MyGUI.
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MyGUI is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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MyGUI is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with MyGUI. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef __MYGUI_BITWISE_H__
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#define __MYGUI_BITWISE_H__
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#include "MyGUI_Prerequest.h"
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namespace MyGUI
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{
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class Bitwise
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{
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public:
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/** Returns the closest power-of-two number greater or equal to value.
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*/
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template<typename Type>
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static MYGUI_FORCEINLINE Type firstPO2From(Type _value)
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{
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--_value;
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_value |= _value >> 16;
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_value |= _value >> 8;
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_value |= _value >> 4;
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_value |= _value >> 2;
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_value |= _value >> 1;
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++_value;
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return _value;
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}
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/** Determines whether the number is power-of-two or not. */
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template<typename Type>
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static MYGUI_FORCEINLINE bool isPO2(Type _value)
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{
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return (_value & (_value - 1)) == 0;
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}
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/** Returns the number of bits a pattern must be shifted right by to
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remove right-hand zeros.
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*/
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template<typename Type>
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static MYGUI_FORCEINLINE size_t getBitShift(Type _mask)
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{
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if (_mask == 0)
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return 0;
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size_t result = 0;
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while ((_mask & 1) == 0)
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{
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++result;
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_mask >>= 1;
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}
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return result;
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}
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};
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} // namespace MyGUI
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#endif // __MYGUI_BITWISE_H__
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