1  /******************************************************************************


2  Copyright (c) 2014 Ryan Juckett


3  http://www.ryanjuckett.com/


4 


5  This software is provided 'asis', without any express or implied


6  warranty. In no event will the authors be held liable for any damages


7  arising from the use of this software.


8 


9  Permission is granted to anyone to use this software for any purpose,


10  including commercial applications, and to alter it and redistribute it


11  freely, subject to the following restrictions:


12 


13  1. The origin of this software must not be misrepresented; you must not


14  claim that you wrote the original software. If you use this software


15  in a product, an acknowledgment in the product documentation would be


16  appreciated but is not required.


17 


18  2. Altered source versions must be plainly marked as such, and must not be


19  misrepresented as being the original software.


20 


21  3. This notice may not be removed or altered from any source


22  distribution.


23  ******************************************************************************/


24 


25  #ifndef RJ__Math_h


26  #define RJ__Math_h


27 


28  #include "Standard.h"


29 


30  //******************************************************************************


31  // Get the log base 2 of a 32bit unsigned integer.


32  // http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogLookup


33  //******************************************************************************


34  tU32 LogBase2( tU32 val );


35 


36  //******************************************************************************


37  // Get the log base 2 of a 64bit unsigned integer.


38  //******************************************************************************


39  inline tU32 LogBase2( tU64 val )


40  {


41  tU64 temp;


42 


43  temp = val >> 32;


44  if (temp)


45  return 32 + LogBase2((tU32)temp);


46 


47  return LogBase2((tU32)val);


48  }


49 


50  #endif

