MyGUI  3.0.1
MyGUI_Bitwise.h
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1 
7 /*
8  This file is part of MyGUI.
9 
10  MyGUI is free software: you can redistribute it and/or modify
11  it under the terms of the GNU Lesser General Public License as published by
12  the Free Software Foundation, either version 3 of the License, or
13  (at your option) any later version.
14 
15  MyGUI is distributed in the hope that it will be useful,
16  but WITHOUT ANY WARRANTY; without even the implied warranty of
17  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18  GNU Lesser General Public License for more details.
19 
20  You should have received a copy of the GNU Lesser General Public License
21  along with MyGUI. If not, see <http://www.gnu.org/licenses/>.
22 */
23 #ifndef __MYGUI_BITWISE_H__
24 #define __MYGUI_BITWISE_H__
25 
26 #include "MyGUI_Prerequest.h"
27 
28 namespace MyGUI
29 {
30 
31  class Bitwise
32  {
33  public:
36  template<typename Type>
37  static MYGUI_FORCEINLINE Type firstPO2From(Type _value)
38  {
39  --_value;
40  _value |= _value >> 16;
41  _value |= _value >> 8;
42  _value |= _value >> 4;
43  _value |= _value >> 2;
44  _value |= _value >> 1;
45  ++_value;
46  return _value;
47  }
48 
50  template<typename Type>
51  static MYGUI_FORCEINLINE bool isPO2(Type _value)
52  {
53  return (_value & (_value-1)) == 0;
54  }
55 
59  template<typename Type>
60  static MYGUI_FORCEINLINE size_t getBitShift(Type _mask)
61  {
62  if (_mask == 0)
63  return 0;
64 
65  size_t result = 0;
66  while ((_mask & 1) == 0)
67  {
68  ++result;
69  _mask >>= 1;
70  }
71  return result;
72  }
73 
74  };
75 
76 } // namespace MyGUI
77 
78 #endif // __MYGUI_BITWISE_H__