PACK file decompilation

FindInArchive.cxx

SLibEntryRef __thiscall SFileSystem__FindInArchive(SFileSystem *this, int index, const char *str)
{
  SLibEntryRef result; // qax@3
  char name_offset; // ST13_1@14
  const char *name; // ST18_4@14
  unsigned __int8 name_length; // ST12_1@14
  SFileSystem *self; // [sp+0h] [bp-14h]@1
  int cmp; // [sp+8h] [bp-Ch]@14
  SLibEntryHead *lib_entry; // [sp+Ch] [bp-8h]@13
  SLibEntryRef *ref; // [sp+Ch] [bp-8h]@14
  SLibEntryTail *tail; // [sp+Ch] [bp-8h]@15
  ptrdiff_t right_child; // [sp+Ch] [bp-8h]@19
  int i; // [sp+10h] [bp-4h]@8

  self = this;
  if ( index < 0
    || index >= this->count
    || (result.offset = (int)str, *str == '/')
    || (result.offset = *str, result.offset == '\\')
    || *str && (result.offset = (int)str, str[1] == ':') )
  {
    result.size = 0;
  }
  else
  {
    strcpy(find_what, str);
    _strlwr(find_what);
    for ( i = (int)find_what; *(_BYTE *)i; ++i )
    {
      if ( *(_BYTE *)i == '\\' )
        *(_BYTE *)i = '/';
    }
    for ( lib_entry = *(SLibEntryHead **)&self->libs[12 * index + 8];
          ;
          lib_entry = (SLibEntryHead *)(*(_DWORD *)right_child + *(_DWORD *)&self->libs[12 * index + 8]) )
    {
      while ( 1 )
      {
        name_offset = lib_entry->name_offset;
        name = &lib_entry->name_length;
        name_length = *name++;
        cmp = strncmp(&find_what[(unsigned __int8)name_offset], name, name_length);
        result.offset = (int)&name[name_length];
        ref = (SLibEntryRef *)&name[name_length];
        if ( cmp >= 0 )
          break;
        tail = (SLibEntryTail *)&ref[1];
        result.offset = tail->has_left_child;
        if ( !tail->has_left_child )
        {
          result.size = 0;
          return result;
        }
        lib_entry = (SLibEntryHead *)&tail[1];
      }
      if ( cmp <= 0 )
        break;
      right_child = (ptrdiff_t)((char *)&ref[1].size + 1);// SLibEntryTail.right_child
      result.offset = right_child;
      if ( !*(_DWORD *)right_child )
      {
        result.size = 0;
        return result;
      }
    }
    result.size = (int)ref;
  }
  return result;
}

LoadFile.cxx

void *__thiscall SFileSystem__LoadFile(SFileSystem *this, const char *archived_name, int loglevel)
{
  void *result; // eax@8
  void *file_open_read; // [sp+0h] [bp-3Ch]@15
  void *archived_file; // [sp+4h] [bp-38h]@6
  SFileSystem *self; // [sp+8h] [bp-34h]@1
  void *file_open_read_mem; // [sp+Ch] [bp-30h]@14
  void *archived_file_mem; // [sp+14h] [bp-28h]@5
  int packfile; // [sp+1Ch] [bp-20h]@4
  int offset; // [sp+20h] [bp-1Ch]@3
  int index; // [sp+24h] [bp-18h]@1
  int assetfile; // [sp+28h] [bp-14h]@13
  int filename; // [sp+2Ch] [bp-10h]@13

  self = this;
  for ( index = 0; index < self->count; ++index )
  {
    offset = (unsigned __int64)SFileSystem__FindInArchive(self, index, archived_name);
    if ( offset )
    {
      packfile = _open(*(const char **)&self->libs[12 * index], 0x8000u);
      if ( packfile < 0 )
      {
        if ( loglevel )
          panic(global_logger, "%s: Couldn't open (%s)", loglevel, *(_DWORD *)&self->libs[12 * index]);
        result = 0;
      }
      else
      {
        logMessage(global_logger, 2, "ARCHIVED FILE(%s)", archived_name);
        archived_file_mem = operator new(0x30u);
        if ( archived_file_mem )
          archived_file = SArchivedFile__ctor(
                            archived_file_mem,
                            packfile,
                            *(_DWORD *)offset + *(_DWORD *)&self->libs[12 * index + 4] + 16,
                            *(_DWORD *)(offset + 4));
        else
          archived_file = 0;
        result = archived_file;
      }
      return result;
    }
  }
  filename = getUnarchivedName((const char **)self, archived_name);
  assetfile = _open((const char *)filename, 0x8000u);
  if ( assetfile < 0 )
  {
    if ( loglevel )
      panic(global_logger, "%s: Couldn't open (%s)", loglevel, filename);
    result = 0;
  }
  else
  {
    logMessage(global_logger, 2, "FILE OPEN READ(%s) = %d", archived_name, assetfile);
    file_open_read_mem = operator new(0x28u);
    if ( file_open_read_mem )
      file_open_read = SFileOpenRead__ctor(file_open_read_mem, assetfile, 1, 0);
    else
      file_open_read = 0;
    result = file_open_read;
  }
  return result;
}

OpenArchive.cxx

int __thiscall SFileSystem__OpenArchive(SFileSystem *this, const char *filename)
{
  SFileSystem *self; // [sp+0h] [bp-14h]@1
  int file; // [sp+8h] [bp-Ch]@1
  int buf; // [sp+Ch] [bp-8h]@3
  int r; // [sp+10h] [bp-4h]@3

  self = this;
  file = _open(filename, 0x8000u);
  if ( file < 0 )
    panic(global_logger, "SFileSystem::OpenArchive: Couldn't open (%s)", filename);
  r = _read(file, &buf, 4u);
  if ( r != 4 || buf != '\x1B\x1ArS' )          // ident 1
    panic(global_logger, "SFileSystem::OpenArchive: %s: Not a Stormregion file", filename);
  r = _read(file, &buf, 4u);
  if ( r != 4 || buf != 0xA870A0D )             // ident 2
    panic(global_logger, "SFileSystem::OpenArchive: %s: Not a Stormregion file", filename);
  r = _read(file, &buf, 4u);
  if ( r != 4 || buf != 'KCAP' )                // 'PACK'
    panic(global_logger, "SFileSystem::OpenArchive: %s: Not a 'PACK' file", filename);
  r = _read(file, &buf, 4u);                    // lib size
  if ( r != 4 )
    panic(global_logger, "SFileSystem::OpenArchive: %s: Read error", filename);
  *(_DWORD *)&self->libs[12 * self->count] = _strdup(filename);
  *(_DWORD *)&self->libs[12 * self->count + 4] = buf;
  *(_DWORD *)&self->libs[12 * self->count + 8] = operator new(*(_DWORD *)&self->libs[12 * self->count + 4]);
  r = _read(file, *(void **)&self->libs[12 * self->count + 8], *(_DWORD *)&self->libs[12 * self->count + 4]);
  if ( r != *(_DWORD *)&self->libs[12 * self->count + 4] )
    panic(global_logger, "SFileSystem::OpenArchive: %s: Read error", filename);
  ++self->count;
  return _close(file);
}

sturcts.s

00000000 SFileSystem     struc ; (sizeof=0xFFFF)
00000000 field_0         dd ?
00000004 field_4         dd ?
00000008 field_8         dd ?
0000000C count           dd ?
00000010 libs            db 65519 dup(?)
0000FFFF SFileSystem     ends
0000FFFF
00000000 ; ---------------------------------------------------------------------------
00000000
00000000 SArchive        struc ; (sizeof=0xC)
00000000 name            dd ?
00000004 lib_length      dd ?
00000008 lib             dd ?
0000000C SArchive        ends
0000000C
00000000 ; ---------------------------------------------------------------------------
00000000
00000000 SLibEntryRef    struc ; (sizeof=0x8)
00000000 size            dd ?
00000004 offset          dd ?
00000008 SLibEntryRef    ends
00000008
00000000 ; ---------------------------------------------------------------------------
00000000
00000000 SLibEntryTail   struc ; (sizeof=0x5)
00000000 has_left_child  db ?
00000001 right_child     dd ?
00000005 SLibEntryTail   ends
00000005
00000000 ; ---------------------------------------------------------------------------
00000000
00000000 SLibEntryHead   struc ; (sizeof=0x101)
00000000 name_offset     db ?
00000001 name_length     db ?
00000002 name            db 255 dup(?)           ; char
00000101 SLibEntryHead   ends