118 lines
5.2 KiB
C++
118 lines
5.2 KiB
C++
/*
|
|
** Command & Conquer Renegade(tm)
|
|
** Copyright 2025 Electronic Arts Inc.
|
|
**
|
|
** 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 3 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, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
/***************************************************************************
|
|
*** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S ***
|
|
***************************************************************************
|
|
* *
|
|
* Project Name : G *
|
|
* *
|
|
* $Archive:: /G/ww3d/POT.CPP $*
|
|
* *
|
|
* $Author:: Naty_h $*
|
|
* *
|
|
* $Modtime:: 12/23/98 7:58a $*
|
|
* *
|
|
* $Revision:: 3 $*
|
|
* *
|
|
*-------------------------------------------------------------------------*
|
|
* Functions: *
|
|
* Find_POT -- finds closest inclusive power of 2 to a value *
|
|
* Find_POT_Log2 -- finds log2 of closest inclusive power of 2 to a value*
|
|
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
|
|
|
|
#include "pot.h"
|
|
|
|
/**************************************************************************
|
|
* Find_POT -- finds closest inclusive power of 2 to a value *
|
|
* *
|
|
* INPUT: *
|
|
* *
|
|
* OUTPUT: *
|
|
* *
|
|
* WARNINGS: *
|
|
* *
|
|
* HISTORY: *
|
|
* 10/20/1997 PWG : Created. *
|
|
*========================================================================*/
|
|
int Find_POT(int val)
|
|
{
|
|
// clear out the recorded position and the recorded count
|
|
int recpos = 0;
|
|
int reccnt = 0;
|
|
|
|
// walk through the value shifting off bits and record the
|
|
// position of the highest bit, and whether we have found
|
|
// more than one bit.
|
|
for (int lp = 0; val; lp++) {
|
|
if (val & 1) {
|
|
recpos = lp;
|
|
reccnt++;
|
|
}
|
|
val >>= 1;
|
|
}
|
|
// if we have not found more than one bit then the number
|
|
// was the power of two so return it.
|
|
if (reccnt < 2) {
|
|
return( 1 << recpos);
|
|
}
|
|
// if we found more than one bit, then the number needs to
|
|
// be rounded up to the next highest power of 2.
|
|
return( 1 << (recpos + 1));
|
|
}
|
|
|
|
|
|
/**************************************************************************
|
|
* Find_POT_Log2 -- finds log2 of closest inclusive power of 2 to a value *
|
|
* *
|
|
* INPUT: *
|
|
* *
|
|
* OUTPUT: *
|
|
* *
|
|
* WARNINGS: *
|
|
* *
|
|
* HISTORY: *
|
|
* 12/23/1998 NH : Created. *
|
|
*========================================================================*/
|
|
unsigned int Find_POT_Log2(unsigned int val)
|
|
{
|
|
// clear out the recorded position and the recorded count
|
|
int recpos = 0;
|
|
int reccnt = 0;
|
|
|
|
// walk through the value shifting off bits and record the
|
|
// position of the highest bit, and whether we have found
|
|
// more than one bit.
|
|
for (int lp = 0; val; lp++) {
|
|
if (val & 1) {
|
|
recpos = lp;
|
|
reccnt++;
|
|
}
|
|
val >>= 1;
|
|
}
|
|
// if we have not found more than one bit then the number
|
|
// was the power of two so return it.
|
|
if (reccnt < 2) {
|
|
return recpos;
|
|
}
|
|
// if we found more than one bit, then the number needs to
|
|
// be rounded up to the next highest power of 2.
|
|
return recpos + 1;
|
|
}
|
|
|
|
|