Initial import of the work in progress M4 engine

svn-id: r31600

engines/m4/saveload.cpp

@@ -0,0 +1,168 @@
+/* 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#include "common/file.h"
+#include "common/savefile.h"
+
+#include "m4/m4.h"
+#include "m4/saveload.h"
+#include "m4/sprite.h"
+
+namespace M4 {
+
+const char *orionSavesList = "saves.dir";
+
+SaveLoad::SaveLoad(M4Engine *vm) : _vm(vm) {
+	// For Orion Burger, check the existance of a 'saves.dir' file to determine whether to
+	// act exactly like the original. Otherwise, we'll use the ScummVM standard, where we'll
+	// keep all the data for a savegame in a single file
+	
+	Common::File file;
+	_emulateOriginal = file.exists(orionSavesList);
+}
+
+const char *SaveLoad::generateSaveName(int slotNumber) {
+	static char buffer[15];
+
+	sprintf(buffer, _emulateOriginal ? "burg%.3d.sav" : "burger.%.3d", slotNumber);
+	return buffer;
+}
+
+bool SaveLoad::hasSaves() {
+	// Return true if a savegame file exists for the first slot
+
+	if (_emulateOriginal) {
+		Common::File f;
+		return f.exists(generateSaveName(1));
+
+	} else {
+		Common::ReadStream *f = _vm->saveManager()->openForLoading(generateSaveName(1));
+		if (f == NULL)
+			return false;
+
+		delete f;
+		return true;
+	}
+}
+
+SaveGameList *SaveLoad::getSaves() {
+	SaveGameList *result = new SaveGameList();
+	char saveName[MAX_SAVEGAME_NAME];
+	Common::ReadStream *f = NULL;
+
+	if (_emulateOriginal) {
+		Common::File *saveFile = new Common::File();
+		saveFile->open(orionSavesList);
+		f = saveFile;
+	}
+
+	for (int slotNumber = 1; slotNumber <= 99; ++slotNumber) {
+		if (_emulateOriginal) {
+			// Read in savegame name from save directory
+			bool isPresent = (f->readByte() != 0);
+			f->read(&saveName[0], MAX_SAVEGAME_NAME);
+
+			if (isPresent)
+				result->push_back(Common::String(saveName));
+			else {
+				result->push_back(Common::String());
+			}
+
+		} else {
+			// Read in savegame name from savegame files directly
+			Common::ReadStream *saveFile = _vm->saveManager()->openForLoading(
+				generateSaveName(slotNumber));
+			if (!saveFile) {
+				// No savegame prsent at that slot
+				result->push_back(Common::String());
+			} else {
+				// Skip over byte offset
+				assert(saveFile->readUint32LE() < 0x100);
+				
+				// Read in savegame name
+				saveFile->read(&saveName[0], MAX_SAVEGAME_NAME);
+				result->push_back(Common::String(saveName));
+
+				delete saveFile;
+			}
+		}
+	}
+
+	if (_emulateOriginal)
+		delete f;
+
+	return result;
+}
+
+M4Surface *SaveLoad::getThumbnail(int slotNumber) {
+	Common::SeekableReadStream *saveFile;
+	uint32 dataOffset;
+
+	if (_emulateOriginal) {
+		// Get savegame file from original game folder
+		Common::File *f = new Common::File();
+		if (!f->open(generateSaveName(slotNumber))) {
+			delete f;
+			return NULL;
+		}
+
+		saveFile = f;
+	} else {
+		// Open up savegame for access via savefile manager
+		saveFile = _vm->saveManager()->openForLoading(generateSaveName(slotNumber));
+	}
+	if (!saveFile) 
+		return NULL;
+
+	dataOffset = saveFile->readUint32LE();
+	assert(dataOffset < 0x100);
+	saveFile->seek(dataOffset, SEEK_CUR);
+
+	// Read in the sprite data
+
+	saveFile->seek(16, SEEK_CUR);
+	int width = saveFile->readUint32LE();
+	int height = saveFile->readUint32LE();
+	saveFile->seek(21, SEEK_CUR);
+	saveFile->readUint32LE();	// sprite data size
+
+	M4Sprite *result = new M4Sprite(saveFile, 0, 0, width, height);
+	delete saveFile;
+
+	return result;
+}
+
+bool SaveLoad::load(int slotNumber) {
+	// TODO: Currently it's hardcoded to return a failure
+	return false;
+}
+
+bool SaveLoad::save(int slotNumber, Common::String saveName) {
+	// TODO: Currently it's hardcoded to return a failure
+	return false;
+}
+
+
+} // End of namespace M4