gemrb/core/DataStream.cpp

   1 /* GemRB - Infinity Engine Emulator
   2  * Copyright (C) 2003 The GemRB Project
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  17  *
  18  *
  19  */
  20
  21 #include "DataStream.h"
  22
  23 #include "win32def.h"
  24
  25 #include <ctype.h>
  26
  27 static bool EndianSwitch = false;
  28
  29 DataStream::DataStream(void)
  30 {
  31         Pos = 0;
  32         Encrypted = false;
  33 }
  34
  35 DataStream::~DataStream(void)
  36 {
  37 }
  38
  39 void DataStream::SetEndianSwitch(int tmp)
  40 {
  41         EndianSwitch = !! tmp;
  42 }
  43
  44 bool DataStream::IsEndianSwitch()
  45 {
  46         return EndianSwitch;
  47 }
  48
  49 /** Returns true if the stream is encrypted */
  50 bool DataStream::CheckEncrypted()
  51 {
  52         ieWord two;
  53         Seek( 0, GEM_STREAM_START );
  54         Read( &two, 2 );
  55         if (two == 0xFFFF) {
  56                 Pos = 0;
  57                 Encrypted = true;
  58                 size -= 2;
  59                 return true;
  60         }
  61         Seek( 0, GEM_STREAM_START );
  62         Encrypted = false;
  63         return false;
  64 }
  65 /** No descriptions */
  66 void DataStream::ReadDecrypted(void* buf, unsigned int size)
  67 {
  68         for (unsigned int i = 0; i < size; i++)
  69                 ( ( unsigned char * ) buf )[i] ^= GEM_ENCRYPTION_KEY[( Pos + i ) & 63];
  70 }
  71
  72 void DataStream::Rewind()
  73 {
  74         Seek( Encrypted ? 2 : 0, GEM_STREAM_START );
  75         Pos = 0;
  76 }
  77
  78 unsigned long DataStream::GetPos() const
  79 {
  80         return Pos;
  81 }
  82
  83 unsigned long DataStream::Size() const
  84 {
  85         return size;
  86 }
  87
  88 unsigned long DataStream::Remains() const
  89 {
  90         return size-Pos;
  91 }
  92
  93 int DataStream::ReadWord(ieWord *dest)
  94 {
  95         int len = Read(dest, 2);
  96         if (EndianSwitch) {
  97                 unsigned char tmp;
  98                 tmp=((unsigned char *) dest)[0];
  99                 ((unsigned char *) dest)[0]=((unsigned char *) dest)[1];
 100                 ((unsigned char *) dest)[1]=tmp;
 101         }
 102         return len;
 103 }
 104
 105 int DataStream::ReadWordSigned(ieWordSigned *dest)
 106 {
 107         int len = Read(dest, 2);
 108         if (EndianSwitch) {
 109                 unsigned char tmp;
 110                 tmp=((unsigned char *) dest)[0];
 111                 ((unsigned char *) dest)[0]=((unsigned char *) dest)[1];
 112                 ((unsigned char *) dest)[1]=tmp;
 113         }
 114         return len;
 115 }
 116
 117 int DataStream::WriteWord(const ieWord *src)
 118 {
 119         int len;
 120         if (EndianSwitch) {
 121                 char tmp[2];
 122                 tmp[0]=((unsigned char *) src)[1];
 123                 tmp[1]=((unsigned char *) src)[0];
 124                 len = Write( tmp, 2 );
 125         }
 126         else {
 127                 len = Write( src, 2 );
 128         }
 129         return len;
 130 }
 131
 132 int DataStream::ReadDword(ieDword *dest)
 133 {
 134         int len = Read(dest, 4);
 135         if (EndianSwitch) {
 136                 unsigned char tmp;
 137                 tmp=((unsigned char *) dest)[0];
 138                 ((unsigned char *) dest)[0]=((unsigned char *) dest)[3];
 139                 ((unsigned char *) dest)[3]=tmp;
 140                 tmp=((unsigned char *) dest)[1];
 141                 ((unsigned char *) dest)[1]=((unsigned char *) dest)[2];
 142                 ((unsigned char *) dest)[2]=tmp;
 143         }
 144         return len;
 145 }
 146
 147 int DataStream::WriteDword(const ieDword *src)
 148 {
 149         int len;
 150         if (EndianSwitch) {
 151                 char tmp[4];
 152                 tmp[0]=((unsigned char *) src)[3];
 153                 tmp[1]=((unsigned char *) src)[2];
 154                 tmp[2]=((unsigned char *) src)[1];
 155                 tmp[3]=((unsigned char *) src)[0];
 156                 len = Write( tmp, 4 );
 157         }
 158         else {
 159                 len = Write( src, 4 );
 160         }
 161         return len;
 162 }
 163
 164 int DataStream::ReadResRef(ieResRef dest)
 165 {
 166         int len = Read(dest, 8);
 167         int i;
 168         // lowercase the resref
 169         for(i = 0; i < 8; i++) {
 170                 dest[i] = (char) tolower(dest[i]);
 171         }
 172         // remove trailing spaces
 173         for (i = 7; i >= 0; i--) {
 174                 if (dest[i] == ' ') dest[i] = 0;
 175                 else break;
 176         }
 177         // null-terminate
 178         dest[8] = 0;
 179         return len;
 180 }
 181
 182 int DataStream::WriteResRef(const ieResRef src)
 183 {
 184         return Write( src, 8);
 185 }