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 "win32def.h"
  22 #include <ctype.h>
  23 #include "DataStream.h"
  24
  25 static bool EndianSwitch = false;
  26
  27 DataStream::DataStream(void)
  28 {
  29         Pos = 0;
  30         Encrypted = false;
  31 }
  32
  33 DataStream::~DataStream(void)
  34 {
  35 }
  36
  37 void DataStream::SetEndianSwitch(int tmp)
  38 {
  39         EndianSwitch = !! tmp;
  40 }
  41
  42 bool DataStream::IsEndianSwitch()
  43 {
  44         return EndianSwitch;
  45 }
  46
  47 /** Returns true if the stream is encrypted */
  48 bool DataStream::CheckEncrypted()
  49 {
  50         ieWord two;
  51         Seek( 0, GEM_STREAM_START );
  52         Read( &two, 2 );
  53         if (two == 0xFFFF) {
  54                 Pos = 0;
  55                 Encrypted = true;
  56                 size -= 2;
  57                 return true;
  58         }
  59         Seek( 0, GEM_STREAM_START );
  60         Encrypted = false;
  61         return false;
  62 }
  63 /** No descriptions */
  64 void DataStream::ReadDecrypted(void* buf, unsigned int size)
  65 {
  66         for (unsigned int i = 0; i < size; i++)
  67                 ( ( unsigned char * ) buf )[i] ^= GEM_ENCRYPTION_KEY[( Pos + i ) & 63];
  68 }
  69
  70 void DataStream::Rewind()
  71 {
  72         Seek( Encrypted ? 2 : 0, GEM_STREAM_START );
  73         Pos = 0;
  74 }
  75
  76 unsigned long DataStream::GetPos() const
  77 {
  78         return Pos;
  79 }
  80
  81 unsigned long DataStream::Size() const
  82 {
  83         return size;
  84 }
  85
  86 unsigned long DataStream::Remains() const
  87 {
  88         return size-Pos;
  89 }
  90
  91 int DataStream::ReadWord(ieWord *dest)
  92 {
  93         int len = Read(dest, 2);
  94         if (EndianSwitch) {
  95                 unsigned char tmp;
  96                 tmp=((unsigned char *) dest)[0];
  97                 ((unsigned char *) dest)[0]=((unsigned char *) dest)[1];
  98                 ((unsigned char *) dest)[1]=tmp;
  99         }
 100         return len;
 101 }
 102
 103 int DataStream::ReadWordSigned(ieWordSigned *dest)
 104 {
 105         int len = Read(dest, 2);
 106         if (EndianSwitch) {
 107                 unsigned char tmp;
 108                 tmp=((unsigned char *) dest)[0];
 109                 ((unsigned char *) dest)[0]=((unsigned char *) dest)[1];
 110                 ((unsigned char *) dest)[1]=tmp;
 111         }
 112         return len;
 113 }
 114
 115 int DataStream::WriteWord(const ieWord *src)
 116 {
 117         int len;
 118         if (EndianSwitch) {
 119                 char tmp[2];
 120                 tmp[0]=((unsigned char *) src)[1];
 121                 tmp[1]=((unsigned char *) src)[0];
 122                 len = Write( tmp, 2 );
 123         }
 124         else {
 125                 len = Write( src, 2 );
 126         }
 127         return len;
 128 }
 129
 130 int DataStream::ReadDword(ieDword *dest)
 131 {
 132         int len = Read(dest, 4);
 133         if (EndianSwitch) {
 134                 unsigned char tmp;
 135                 tmp=((unsigned char *) dest)[0];
 136                 ((unsigned char *) dest)[0]=((unsigned char *) dest)[3];
 137                 ((unsigned char *) dest)[3]=tmp;
 138                 tmp=((unsigned char *) dest)[1];
 139                 ((unsigned char *) dest)[1]=((unsigned char *) dest)[2];
 140                 ((unsigned char *) dest)[2]=tmp;
 141         }
 142         return len;
 143 }
 144
 145 int DataStream::WriteDword(const ieDword *src)
 146 {
 147         int len;
 148         if (EndianSwitch) {
 149                 char tmp[4];
 150                 tmp[0]=((unsigned char *) src)[3];
 151                 tmp[1]=((unsigned char *) src)[2];
 152                 tmp[2]=((unsigned char *) src)[1];
 153                 tmp[3]=((unsigned char *) src)[0];
 154                 len = Write( tmp, 4 );
 155         }
 156         else {
 157                 len = Write( src, 4 );
 158         }
 159         return len;
 160 }
 161
 162 int DataStream::ReadResRef(ieResRef dest)
 163 {
 164         int len = Read(dest, 8);
 165         int i;
 166         // lowercase the resref
 167         for(i = 0; i < 8; i++) {
 168                 dest[i] = (char) tolower(dest[i]);
 169         }
 170         // remove trailing spaces
 171         for (i = 7; i >= 0; i--) {
 172                 if (dest[i] == ' ') dest[i] = 0;
 173                 else break;
 174         }
 175         // null-terminate
 176         dest[8] = 0;
 177         return len;
 178 }
 179
 180 int DataStream::WriteResRef(const ieResRef src)
 181 {
 182         return Write( src, 8);
 183 }