fceux/endian.cpp

104 lines
2.2 KiB
C++

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2002 Xodnizel
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* Contains file I/O functions that write/read data */
/* LSB first. */
#include <stdio.h>
#include "types.h"
#include "endian.h"
void FlipByteOrder(uint8 *src, uint32 count)
{
uint8 *start=src;
uint8 *end=src+count-1;
if((count&1) || !count) return; /* This shouldn't happen. */
while(count--)
{
uint8 tmp;
tmp=*end;
*end=*start;
*start=tmp;
end--;
start++;
}
}
int write16le(uint16 b, FILE *fp)
{
uint8 s[2];
s[0]=b;
s[1]=b>>8;
return((fwrite(s,1,2,fp)<2)?0:2);
}
int write32le(uint32 b, FILE *fp)
{
uint8 s[4];
s[0]=b;
s[1]=b>>8;
s[2]=b>>16;
s[3]=b>>24;
return((fwrite(s,1,4,fp)<4)?0:4);
}
int read32le(uint32 *Bufo, FILE *fp)
{
uint32 buf;
if(fread(&buf,1,4,fp)<4)
return 0;
#ifdef LSB_FIRST
*(uint32*)Bufo=buf;
#else
*(uint32*)Bufo=((buf&0xFF)<<24)|((buf&0xFF00)<<8)|((buf&0xFF0000)>>8)|((buf&0xFF000000)>>24);
#endif
return 1;
}
int read16le(char *d, FILE *fp)
{
#ifdef LSB_FIRST
return((fread(d,1,2,fp)<2)?0:2);
#else
int ret;
ret=fread(d+1,1,1,fp);
ret+=fread(d,1,1,fp);
return ret<2?0:2;
#endif
}
void FCEU_en32lsb(uint8 *buf, uint32 morp)
{
buf[0]=morp;
buf[1]=morp>>8;
buf[2]=morp>>16;
buf[3]=morp>>24;
}
uint32 FCEU_de32lsb(uint8 *morp)
{
return(morp[0]|(morp[1]<<8)|(morp[2]<<16)|(morp[3]<<24));
}