beetle-psx-libretro/mednafen/mednafen-endian.c

/* Mednafen - Multi-system Emulator
 *
 * 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
 */

#include "mednafen-endian.h"

void Endian_A16_Swap(void *src, uint32_t nelements)
{
   uint32_t i;
   uint8_t *nsrc = (uint8_t *)src;

   for(i = 0; i < nelements; i++)
   {
      uint8_t tmp = nsrc[i * 2];

      nsrc[i * 2] = nsrc[i * 2 + 1];
      nsrc[i * 2 + 1] = tmp;
   }
}

void Endian_A32_Swap(void *src, uint32_t nelements)
{
   uint32_t i;
   uint8_t *nsrc = (uint8_t *)src;

   for(i = 0; i < nelements; i++)
   {
      uint8_t tmp1 = nsrc[i * 4];
      uint8_t tmp2 = nsrc[i * 4 + 1];

      nsrc[i * 4] = nsrc[i * 4 + 3];
      nsrc[i * 4 + 1] = nsrc[i * 4 + 2];

      nsrc[i * 4 + 2] = tmp2;
      nsrc[i * 4 + 3] = tmp1;
   }
}

void Endian_A64_Swap(void *src, uint32_t nelements)
{
   uint32_t i;
   uint8_t *nsrc = (uint8_t *)src;

   for(i = 0; i < nelements; i++)
   {
      unsigned z;
      uint8_t *base = &nsrc[i * 8];

      for(z = 0; z < 4; z++)
      {
         uint8_t tmp = base[z];

         base[z] = base[7 - z];
         base[7 - z] = tmp;
      }
   }
}

void Endian_A16_LE_to_NE(void *src, uint32_t nelements)
{
#ifdef MSB_FIRST
   uint32_t i;
   uint8_t *nsrc = (uint8_t *)src;

   for(i = 0; i < nelements; i++)
   {
      uint8_t tmp = nsrc[i * 2];

      nsrc[i * 2] = nsrc[i * 2 + 1];
      nsrc[i * 2 + 1] = tmp;
   }
#endif
}

void Endian_A16_BE_to_NE(void *src, uint32_t nelements)
{
#ifndef MSB_FIRST
   uint32_t i;
   uint8_t *nsrc = (uint8_t *)src;

   for(i = 0; i < nelements; i++)
   {
      uint8_t tmp = nsrc[i * 2];

      nsrc[i * 2] = nsrc[i * 2 + 1];
      nsrc[i * 2 + 1] = tmp;
   }
#endif
}


void Endian_A32_LE_to_NE(void *src, uint32_t nelements)
{
#ifdef MSB_FIRST
   uint32_t i;
   uint8_t *nsrc = (uint8_t *)src;

   for(i = 0; i < nelements; i++)
   {
      uint8_t tmp1 = nsrc[i * 4];
      uint8_t tmp2 = nsrc[i * 4 + 1];

      nsrc[i * 4] = nsrc[i * 4 + 3];
      nsrc[i * 4 + 1] = nsrc[i * 4 + 2];

      nsrc[i * 4 + 2] = tmp2;
      nsrc[i * 4 + 3] = tmp1;
   }
#endif
}

void Endian_A64_LE_to_NE(void *src, uint32_t nelements)
{
#ifdef MSB_FIRST
   uint32_t i;
   uint8_t *nsrc = (uint8_t *)src;

   for(i = 0; i < nelements; i++)
   {
      unsigned z;
      uint8_t *base = &nsrc[i * 8];

      for(z = 0; z < 4; z++)
      {
         uint8_t tmp = base[z];

         base[z] = base[7 - z];
         base[7 - z] = tmp;
      }
   }
#endif
}

void FlipByteOrder(uint8_t *src, uint32_t count)
{
   uint8_t *start=src;
   uint8_t *end=src+count-1;

   if((count&1) || !count)
      return;         /* This shouldn't happen. */

   count >>= 1;

   while(count--)
   {
      uint8_t tmp;

      tmp=*end;
      *end=*start;
      *start=tmp;
      end--;
      start++;
   }
}

int read32le(uint32_t *Bufo, FILE *fp)
{
   uint32_t buf;
   if(fread(&buf,1,4,fp)<4)
      return 0;
#ifdef MSB_FIRST
   *(uint32_t*)Bufo=((buf&0xFF)<<24)|((buf&0xFF00)<<8)|((buf&0xFF0000)>>8)|((buf&0xFF000000)>>24);
#else
   *(uint32_t*)Bufo=buf;
#endif
   return 1;
}

int read16le(char *d, FILE *fp)
{
#ifdef MSB_FIRST
   int ret=fread(d+1,1,1,fp);
   ret+=fread(d,1,1,fp);
   return ret<2?0:2;
#else
   return((fread(d,1,2,fp)<2)?0:2);
#endif
}