dc9950d1c8
- - Fix the template trickery with this one word fix to Volume.inl. For the reason, see http://www.parashift.com/c++-faq-lite/templates.html#faq-35.18 - Add newlines to two more files so that PolyVox build with no warnings at all.
60 lines
1.7 KiB
C++
60 lines
1.7 KiB
C++
#pragma region License
|
|
/******************************************************************************
|
|
This file is part of the PolyVox library
|
|
Copyright (C) 2006 David Williams
|
|
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License
|
|
as published by the Free Software Foundation; either version 2
|
|
of the License, or (at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
******************************************************************************/
|
|
#pragma endregion
|
|
|
|
#include "Utility.h"
|
|
|
|
#include <cassert>
|
|
|
|
namespace PolyVox
|
|
{
|
|
//Note: this function only works for inputs which are a power of two and not zero
|
|
//If this is not the case then the output is undefined.
|
|
boost::uint8_t logBase2(boost::uint32_t uInput)
|
|
{
|
|
assert(uInput != 0);
|
|
assert(isPowerOf2(uInput));
|
|
|
|
boost::uint8_t result = 0;
|
|
uInput = uInput >> 1;
|
|
while(uInput)
|
|
{
|
|
uInput = uInput >> 1;
|
|
++result;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
bool isPowerOf2(boost::uint32_t uInput)
|
|
{
|
|
boost::uint8_t uNonZeroBits = 0;
|
|
boost::uint32_t uMask = 0x00000001;
|
|
for(boost::uint8_t ct = 0; ct < 32; ++ct)
|
|
{
|
|
if(uInput & uMask)
|
|
{
|
|
++uNonZeroBits;
|
|
}
|
|
uMask = uMask << 1;
|
|
}
|
|
return uNonZeroBits == 1 ? true : false;
|
|
}
|
|
}
|