tools/flexcat/src/swapfuncs.c

   1 /*
   2  * $Id$
   3  *
   4  * Copyright (C) 1993-1999 by Jochen Wiedmann and Marcin Orlowski
   5  * Copyright (C) 2002-2010 by the FlexCat Open Source Team
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or (at
  10  * your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  */
  22
  23 #include "flexcat.h"
  24
  25 /// Swappers...
  26
  27 unsigned short (*SwapWord)(unsigned short r) = NULL;
  28 uint32 (*SwapLong)(uint32 r) = NULL;
  29
  30 unsigned short SwapWord21(unsigned short r)
  31 {
  32   return (unsigned short)(((r & 0xff00) >> 8) | ((r & 0x00ff) << 8));
  33 }
  34
  35 unsigned short SwapWord12(unsigned short r)
  36 {
  37   return r;
  38 }
  39
  40 uint32 SwapLong4321(uint32 r)
  41 {
  42   return (((r & 0xff000000) >> 24) | ((r & 0x00ff0000) >> 8) | ((r & 0x0000ff00) << 8) | ((r & 0x000000ff) << 24));
  43 }
  44 uint32 SwapLong1234(uint32 r)
  45 {
  46   return r;
  47 }
  48 ///
  49 /// SwapChoose
  50
  51 int SwapChoose(void)
  52 {
  53   unsigned short w;
  54   uint32 d;
  55
  56   strncpy((char *)&w, "\1\2", 2);
  57   strncpy((char *)&d, "\1\2\3\4", 4);
  58
  59   if(w == 0x0201)
  60     SwapWord = SwapWord21;
  61   else if(w == 0x0102)
  62     SwapWord = SwapWord12;
  63   else
  64     return 0;
  65
  66   if(d == 0x04030201)
  67     SwapLong = SwapLong4321;
  68   else if(d == 0x01020304)
  69     SwapLong = SwapLong1234;
  70   else
  71     return 0;
  72
  73   return 1;
  74 }
  75 ///