MyGUI_Bitwise.h

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/*
 * This source file is part of MyGUI. For the latest info, see http://mygui.info/
 * Distributed under the MIT License
 * (See accompanying file COPYING.MIT or copy at http://opensource.org/licenses/MIT)
 */

#ifndef __MYGUI_BITWISE_H__
#define __MYGUI_BITWISE_H__

#include "MyGUI_Prerequest.h"

namespace MyGUI
{

    class Bitwise
    {
    public:
        template<typename Type>
        static MYGUI_FORCEINLINE Type firstPO2From(Type _value)
        {
            --_value;
            _value |= _value >> 16;
            _value |= _value >> 8;
            _value |= _value >> 4;
            _value |= _value >> 2;
            _value |= _value >> 1;
            ++_value;
            return _value;
        }

        template<typename Type>
        static MYGUI_FORCEINLINE bool isPO2(Type _value)
        {
            return (_value & (_value - 1)) == 0;
        }

        template<typename Type>
        static MYGUI_FORCEINLINE size_t getBitShift(Type _mask)
        {
            if (_mask == 0)
                return 0;

            size_t result = 0;
            while ((_mask & 1) == 0)
            {
                ++result;
                _mask >>= 1;
            }
            return result;
        }
    };

} // namespace MyGUI

#endif // __MYGUI_BITWISE_H__