scummvm/engines/gnap/detection.cpp
Adrian Frühwirth 00e59a3122 ALL: Load savegame thumbnail only when necessary
This commit introduces the following changes:

1. Graphics::loadThumbnail()

   Now returns a boolean and takes a new argument skipThumbnail which
   defaults to false. In case of true, loadThumbnail() reads past the
   thumbnail data in the input stream instead of actually loading the
   thumbnail. This simplifies savegame handling where, up until now,
   many engines always read the whole savegame metadata (including
   the thumbnail) and then threw away the thumbnail when not needed
   (which is in almost all cases, the most common exception being
   MetaEngine::querySaveMetaInfos() which is responsible for loading
   savegame metadata for displaying it in the GUI launcher.

2. readSavegameHeader()

   Engines which already implement such a method (name varies) now take
   a new argument skipThumbnail (default: true) which is passed
   through to loadThumbnail(). This means that the default case for
   readSavegameHeader() is now _not_ loading the thumbnail from a
   savegame and just reading past it. In those cases, e.g.
   querySaveMetaInfos(), where we actually are interested in loading
   the thumbnail readSavegameHeader() needs to explicitely be called
   with skipThumbnail == false.

   Engines whose readSavegameHeader() (name varies) already takes an
   argument loadThumbnail have been adapted to have a similar
   prototype and semantics.
   I.e. readSaveHeader(in, loadThumbnail, header) now is
   readSaveHeader(in, header, skipThumbnail).

3. Error handling

   Engines which previously did not check the return value of
   readSavegameHeader() (name varies) now do so ensuring that possibly
   broken savegames (be it a broken thumbnail or something else) don't
   make it into the GUI launcher list in the first place.
2018-04-07 09:26:20 +02:00

213 lines
6.0 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "gnap/gnap.h"
#include "common/config-manager.h"
#include "engines/advancedDetector.h"
#include "common/savefile.h"
#include "common/system.h"
#include "base/plugins.h"
#include "graphics/thumbnail.h"
static const PlainGameDescriptor gnapGames[] = {
{ "gnap", "Gnap" },
{ 0, 0 }
};
namespace Gnap {
static const ADGameDescription gameDescriptions[] = {
{
"gnap", "",
{
{"stock_n.dat", 0, "46819043d019a2f36b727cc2bdd6980f", 12515823},
AD_LISTEND
},
Common::EN_ANY, Common::kPlatformWindows, ADGF_NO_FLAGS, GUIO0()
},
{
"gnap", "",
{
{"stock_n.dat", 0, "46819043d019a2f36b727cc2bdd6980f", 13497301},
AD_LISTEND
},
Common::EN_ANY, Common::kPlatformWindows, ADGF_NO_FLAGS, GUIO0()
},
{
"gnap", "",
{
{"stock_n.dat", 0, "46819043d019a2f36b727cc2bdd6980f", 12995485},
AD_LISTEND
},
Common::RU_RUS, Common::kPlatformWindows, ADGF_NO_FLAGS, GUIO0()
},
{
"gnap", "Fargus",
{
{"stock_n.dat", 0, "46819043d019a2f36b727cc2bdd6980f", 12847726},
AD_LISTEND
},
Common::RU_RUS, Common::kPlatformWindows, ADGF_NO_FLAGS, GUIO0()
},
AD_TABLE_END_MARKER
};
} // End of namespace Gnap
class GnapMetaEngine : public AdvancedMetaEngine {
public:
GnapMetaEngine() : AdvancedMetaEngine(Gnap::gameDescriptions, sizeof(ADGameDescription), gnapGames) {
_singleId = "gnap";
_maxScanDepth = 3;
}
virtual const char *getName() const {
return "Gnap";
}
virtual const char *getOriginalCopyright() const {
return "Gnap (C) Artech Digital Entertainment 1997";
}
virtual bool hasFeature(MetaEngineFeature f) const;
virtual bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const;
virtual int getMaximumSaveSlot() const;
virtual SaveStateList listSaves(const char *target) const;
SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const;
virtual void removeSaveState(const char *target, int slot) const;
};
bool GnapMetaEngine::hasFeature(MetaEngineFeature f) const {
return
(f == kSupportsListSaves) ||
(f == kSupportsLoadingDuringStartup) ||
(f == kSupportsDeleteSave) ||
(f == kSavesSupportMetaInfo) ||
(f == kSavesSupportThumbnail) ||
(f == kSavesSupportCreationDate) ||
(f == kSimpleSavesNames);
}
bool Gnap::GnapEngine::hasFeature(EngineFeature f) const {
return
(f == kSupportsRTL) ||
(f == kSupportsLoadingDuringRuntime) ||
(f == kSupportsSavingDuringRuntime);
}
void GnapMetaEngine::removeSaveState(const char *target, int slot) const {
Common::String fileName = Common::String::format("%s.%03d", target, slot);
g_system->getSavefileManager()->removeSavefile(fileName);
}
int GnapMetaEngine::getMaximumSaveSlot() const { return 99; }
SaveStateList GnapMetaEngine::listSaves(const char *target) const {
Common::SaveFileManager *saveFileMan = g_system->getSavefileManager();
Common::StringArray filenames;
Common::String saveDesc;
Common::String pattern = Common::String::format("%s.0##", target);
Gnap::GnapSavegameHeader header;
filenames = saveFileMan->listSavefiles(pattern);
SaveStateList saveList;
for (Common::StringArray::const_iterator file = filenames.begin(); file != filenames.end(); ++file) {
const char *ext = strrchr(file->c_str(), '.');
int slot = ext ? atoi(ext + 1) : -1;
if (slot >= 0 && slot < getMaximumSaveSlot()) {
Common::InSaveFile *in = g_system->getSavefileManager()->openForLoading(*file);
if (in) {
if (Gnap::GnapEngine::readSavegameHeader(in, header))
saveList.push_back(SaveStateDescriptor(slot, header._saveName));
delete in;
}
}
}
// Sort saves based on slot number.
Common::sort(saveList.begin(), saveList.end(), SaveStateDescriptorSlotComparator());
return saveList;
}
SaveStateDescriptor GnapMetaEngine::querySaveMetaInfos(const char *target, int slot) const {
Common::String fileName = Common::String::format("%s.%03d", target, slot);
Common::InSaveFile *file = g_system->getSavefileManager()->openForLoading(fileName);
if (file) {
char saveIdentBuffer[5];
file->read(saveIdentBuffer, 5);
int32 version = file->readByte();
if (version > GNAP_SAVEGAME_VERSION) {
delete file;
return SaveStateDescriptor();
}
Common::String saveName;
char ch;
while ((ch = (char)file->readByte()) != '\0')
saveName += ch;
SaveStateDescriptor desc(slot, saveName);
if (version != 1) {
Graphics::Surface *thumbnail;
if (!Graphics::loadThumbnail(*file, thumbnail)) {
delete file;
return SaveStateDescriptor();
}
desc.setThumbnail(thumbnail);
}
int year = file->readSint16LE();
int month = file->readSint16LE();
int day = file->readSint16LE();
int hour = file->readSint16LE();
int minutes = file->readSint16LE();
desc.setSaveDate(year, month, day);
desc.setSaveTime(hour, minutes);
delete file;
return desc;
}
return SaveStateDescriptor();
}
bool GnapMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
if (desc) {
*engine = new Gnap::GnapEngine(syst, desc);
}
return desc != 0;
}
#if PLUGIN_ENABLED_DYNAMIC(GNAP)
REGISTER_PLUGIN_DYNAMIC(GNAP, PLUGIN_TYPE_ENGINE, GnapMetaEngine);
#else
REGISTER_PLUGIN_STATIC(GNAP, PLUGIN_TYPE_ENGINE, GnapMetaEngine);
#endif