openjpeg/libopenjpeg/fix.c
2005-01-03 17:39:30 +00:00

63 lines
2.0 KiB
C

/*
* Copyright (c) 2001-2002, David Janssens
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "fix.h"
#include <math.h> //Add Antonin : multbug1
#ifdef WIN32
#define int64 __int64
#else
#define int64 long long
#endif
/*
* Multiply two fixed-precision rational numbers.
*/
//int fix_mul(int a, int b)
//{
// return (int) ((int64) a * (int64) b >> 13);
//}
//Mod Antonin : multbug1
/*
int fix_mul(int a, int b)
{
double tmp= (double) ((int64) a * (int64) b);
int64 v = (int64) ((fabs(tmp/8192.0)>=floor(fabs(tmp/8192.0))+0.5)?fabs(tmp/8192.0)+1.0:fabs(tmp/8192.0));
v = (tmp<0)?-v:v;
return (int) v;
}
*/
//doM
int fix_mul(int a, int b) // Luke Lee optimized : 11/16/2004
{
int64 temp = (int64) a * (int64) b >> 12;
return (int) ((temp >> 1) + (temp & 1)) ;
}