diff options
Diffstat (limited to 'engines/glk/advsys/game.cpp')
| -rw-r--r-- | engines/glk/advsys/game.cpp | 44 |
1 files changed, 35 insertions, 9 deletions
diff --git a/engines/glk/advsys/game.cpp b/engines/glk/advsys/game.cpp index ce1da29456..0b9db7e8aa 100644 --- a/engines/glk/advsys/game.cpp +++ b/engines/glk/advsys/game.cpp @@ -26,27 +26,34 @@ namespace Glk { namespace AdvSys { +void Decrypter::decrypt(byte *data, size_t size) { + for (; --size; ++data) + *data = ~(*data + 30); +} + +/*--------------------------------------------------------------------------*/ + #define HEADER_SIZE 62 -void Header::load(Common::ReadStream *s) { +bool Header::load(Common::ReadStream &s) { _valid = false; byte data[HEADER_SIZE]; // Read in the data - if (s->read(data, HEADER_SIZE) != HEADER_SIZE) - return; - Compression::decompress(data, HEADER_SIZE); + if (s.read(data, HEADER_SIZE) != HEADER_SIZE) + return false; + decrypt(data, HEADER_SIZE); Common::MemoryReadStream ms(data, HEADER_SIZE, DisposeAfterUse::NO); // Validate the header _valid = !strncmp((const char*)data + 2, "ADVSYS", 6); if (!_valid) - return; + return false; _size = ms.readUint16LE(); ms.skip(6); _headerVersion = ms.readUint16LE(); - _name = Common::String((const char*)data + 10, (const char*)data + 28); + _name = Common::String((const char *)data + 10, (const char *)data + 28); ms.skip(18); _version = ms.readUint16LE(); _wordTable = ms.readUint16LE(); @@ -65,11 +72,30 @@ void Header::load(Common::ReadStream *s) { _errorHandler = ms.readUint16LE(); _saveArea = ms.readUint16LE(); _saveSize = ms.readUint16LE(); + + return true; } -void Compression::decompress(byte *data, size_t size) { - for (; --size; ++data) - *data = ~(*data + 30); +/*--------------------------------------------------------------------------*/ + +#define MAX_VERSION 102 + +bool Game::load(Common::SeekableReadStream &s) { + // Load the header + s.seek(0); + if (!Header::load(s)) + return false; + + if (_headerVersion < 101 || _headerVersion > MAX_VERSION) + error("Wrong version number"); + + // Load the needed game data and decrypt it + _data.resize(_size); + if (!s.read(&_data[0], _size)) + return false; + decrypt(&_data[0], _size); + + return true; } } // End of namespace AdvSys |