scummvm/engines/draci/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

196 lines
5.4 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 "draci/draci.h"
#include "draci/saveload.h"
#include "base/plugins.h"
#include "common/system.h"
#include "engines/advancedDetector.h"
#include "engines/metaengine.h"
static const PlainGameDescriptor draciGames[] = {
{ "draci", "Draci Historie" },
{ 0, 0 }
};
namespace Draci {
const ADGameDescription gameDescriptions[] = {
{
"draci",
0,
AD_ENTRY1s("INIT.DFW", "b890a5aeebaf16af39219cba2416b0a3", 906),
Common::EN_ANY,
Common::kPlatformDOS,
ADGF_NO_FLAGS,
GUIO0()
},
{
"draci",
0,
AD_ENTRY1s("INIT.DFW", "9921c8f0045679a8f37eca8d41c5ec02", 906),
Common::CZ_CZE,
Common::kPlatformDOS,
ADGF_NO_FLAGS,
GUIO0()
},
{
"draci",
0,
AD_ENTRY1s("INIT.DFW", "76b9b78a8a8809a240acc395df4d0715", 906),
Common::PL_POL,
Common::kPlatformDOS,
ADGF_NO_FLAGS,
GUIO0()
},
{
"draci",
0,
AD_ENTRY1s("INIT.DFW", "9a7115b91cdea361bcaff3e046ac7ded", 906),
Common::DE_DEU,
Common::kPlatformDOS,
ADGF_NO_FLAGS,
GUIO0()
},
AD_TABLE_END_MARKER
};
} // End of namespace Draci
class DraciMetaEngine : public AdvancedMetaEngine {
public:
DraciMetaEngine() : AdvancedMetaEngine(Draci::gameDescriptions, sizeof(ADGameDescription), draciGames) {
_singleId = "draci";
}
virtual const char *getName() const {
return "Draci";
}
virtual const char *getOriginalCopyright() const {
return "Copyright (C) 1995 NoSense";
}
virtual bool hasFeature(MetaEngineFeature f) const;
virtual int getMaximumSaveSlot() const { return 99; }
virtual SaveStateList listSaves(const char *target) const;
virtual void removeSaveState(const char *target, int slot) const;
virtual SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const;
virtual bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const;
};
bool DraciMetaEngine::hasFeature(MetaEngineFeature f) const {
return
(f == kSupportsListSaves) ||
(f == kSupportsDeleteSave) ||
(f == kSavesSupportMetaInfo) ||
(f == kSavesSupportThumbnail) ||
(f == kSavesSupportCreationDate) ||
(f == kSavesSupportPlayTime) ||
(f == kSupportsLoadingDuringStartup);
}
SaveStateList DraciMetaEngine::listSaves(const char *target) const {
Common::SaveFileManager *saveFileMan = g_system->getSavefileManager();
Common::StringArray filenames;
Common::String pattern("draci.s##");
filenames = saveFileMan->listSavefiles(pattern);
SaveStateList saveList;
for (Common::StringArray::const_iterator file = filenames.begin(); file != filenames.end(); ++file) {
// Obtain the last 2 digits of the filename, since they correspond to the save slot
int slotNum = atoi(file->c_str() + file->size() - 2);
if (slotNum >= 0 && slotNum <= 99) {
Common::InSaveFile *in = saveFileMan->openForLoading(*file);
if (in) {
Draci::DraciSavegameHeader header;
if (Draci::readSavegameHeader(in, header)) {
saveList.push_back(SaveStateDescriptor(slotNum, header.saveName));
}
delete in;
}
}
}
// Sort saves based on slot number.
Common::sort(saveList.begin(), saveList.end(), SaveStateDescriptorSlotComparator());
return saveList;
}
void DraciMetaEngine::removeSaveState(const char *target, int slot) const {
g_system->getSavefileManager()->removeSavefile(Draci::DraciEngine::getSavegameFile(slot));
}
SaveStateDescriptor DraciMetaEngine::querySaveMetaInfos(const char *target, int slot) const {
Common::InSaveFile *f = g_system->getSavefileManager()->openForLoading(
Draci::DraciEngine::getSavegameFile(slot));
if (f) {
Draci::DraciSavegameHeader header;
if (!Draci::readSavegameHeader(f, header, false)) {
delete f;
return SaveStateDescriptor();
}
delete f;
// Create the return descriptor
SaveStateDescriptor desc(slot, header.saveName);
desc.setThumbnail(header.thumbnail);
int day = (header.date >> 24) & 0xFF;
int month = (header.date >> 16) & 0xFF;
int year = header.date & 0xFFFF;
desc.setSaveDate(year, month, day);
int hour = (header.time >> 8) & 0xFF;
int minutes = header.time & 0xFF;
desc.setSaveTime(hour, minutes);
desc.setPlayTime(header.playtime * 1000);
return desc;
}
return SaveStateDescriptor();
}
bool DraciMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
if (desc) {
*engine = new Draci::DraciEngine(syst, desc);
}
return desc != 0;
}
#if PLUGIN_ENABLED_DYNAMIC(DRACI)
REGISTER_PLUGIN_DYNAMIC(DRACI, PLUGIN_TYPE_ENGINE, DraciMetaEngine);
#else
REGISTER_PLUGIN_STATIC(DRACI, PLUGIN_TYPE_ENGINE, DraciMetaEngine);
#endif