Stop reconstructing the engine state when restoring, but reset it instead

svn-id: r49376

5 files changed, 69 insertions, 75 deletions

diff --git a/engines/sci/engine/game.cpp b/engines/sci/engine/game.cpp
index 03c3594f03..bc10099e52 100644
--- a/engines/sci/engine/game.cpp
+++ b/engines/sci/engine/game.cpp
@@ -111,7 +111,7 @@ int game_init(EngineState *s) {
 	if (g_sci->_gfxMenu)
 		g_sci->_gfxMenu->reset();
 
-	s->successor = NULL; // No successor
+	s->restoring = false;
 
 	s->game_start_time = g_system->getMillis();
 	s->last_wait_time = s->game_start_time;
@@ -134,9 +134,8 @@ int game_init(EngineState *s) {
 }
 
 int game_exit(EngineState *s) {
-	s->_executionStack.clear();
-
-	if (!s->successor) {
+	if (!s->restoring) {
+		s->_executionStack.clear();
 #ifdef USE_OLD_MUSIC_FUNCTIONS
 		s->_sound.sfx_exit();
 		// Reinit because some other code depends on having a valid state
diff --git a/engines/sci/engine/savegame.cpp b/engines/sci/engine/savegame.cpp
index bba087d953..798f889460 100644
--- a/engines/sci/engine/savegame.cpp
+++ b/engines/sci/engine/savegame.cpp
@@ -821,7 +821,6 @@ static void reconstruct_sounds(EngineState *s) {
 #endif
 
 void gamestate_restore(EngineState *s, Common::SeekableReadStream *fh) {
-	EngineState *retval;
 #ifdef USE_OLD_MUSIC_FUNCTIONS
 	SongLibrary temp;
 #endif
@@ -856,76 +855,66 @@ void gamestate_restore(EngineState *s, Common::SeekableReadStream *fh) {
 		thumbnail = 0;
 	}
 
-	// Create a new EngineState object
-	retval = new EngineState(s->_segMan);
-	retval->_event = s->_event;
-
-	// Copy some old data
-	retval->_soundCmd = s->_soundCmd;
-
-	// Copy memory segment
-	retval->_memorySegmentSize = s->_memorySegmentSize;
-	memcpy(retval->_memorySegment, s->_memorySegment, s->_memorySegmentSize);
-
-	retval->saveLoadWithSerializer(ser);	// FIXME: Error handling?
+	s->reset(true);
+	s->saveLoadWithSerializer(ser);	// FIXME: Error handling?
 
 #ifdef USE_OLD_MUSIC_FUNCTIONS
 	s->_sound.sfx_exit();
 #endif
 
 	// Set exec stack base to zero
-	retval->execution_stack_base = 0;
+	s->execution_stack_base = 0;
 
 	// Now copy all current state information
 
 #ifdef USE_OLD_MUSIC_FUNCTIONS
-	temp = retval->_sound._songlib;
-	retval->_sound.sfx_init(g_sci->getResMan(), s->sfx_init_flags, g_sci->_features->detectDoSoundType());
-	retval->sfx_init_flags = s->sfx_init_flags;
-	retval->_sound._songlib.freeSounds();
-	retval->_sound._songlib = temp;
-	retval->_soundCmd->updateSfxState(&retval->_sound);
+	temp = s->_sound._songlib;
+	s->_sound.sfx_init(g_sci->getResMan(), s->sfx_init_flags, g_sci->_features->detectDoSoundType());
+	s->sfx_init_flags = s->sfx_init_flags;
+	s->_sound._songlib.freeSounds();
+	s->_sound._songlib = temp;
+	s->_soundCmd->updateSfxState(&retval->_sound);
 #endif
 
-	reconstruct_stack(retval);
-	retval->_segMan->reconstructScripts(retval);
-	retval->_segMan->reconstructClones();
-	retval->_gameObj = s->_gameObj;
-	retval->script_000 = retval->_segMan->getScript(retval->_segMan->getScriptSegment(0, SCRIPT_GET_DONT_LOAD));
-	retval->gc_countdown = GC_INTERVAL - 1;
+	reconstruct_stack(s);
+	s->_segMan->reconstructScripts(s);
+	s->_segMan->reconstructClones();
+	s->_gameObj = s->_gameObj;
+	s->script_000 = s->_segMan->getScript(s->_segMan->getScriptSegment(0, SCRIPT_GET_DONT_LOAD));
+	s->gc_countdown = GC_INTERVAL - 1;
 
 	// Time state:
-	retval->last_wait_time = g_system->getMillis();
-	retval->game_start_time = g_system->getMillis();
+	s->last_wait_time = g_system->getMillis();
+	s->game_start_time = g_system->getMillis();
 
-	retval->successor = NULL;
+	s->restoring = false;
 
 #ifdef USE_OLD_MUSIC_FUNCTIONS
-	retval->_sound._it = NULL;
-	retval->_sound._flags = s->_sound._flags;
-	retval->_sound._song = NULL;
-	retval->_sound._suspended = s->_sound._suspended;
-	reconstruct_sounds(retval);
+	s->_sound._it = NULL;
+	s->_sound._flags = s->_sound._flags;
+	s->_sound._song = NULL;
+	s->_sound._suspended = s->_sound._suspended;
+	reconstruct_sounds(s);
 #else
-	retval->_soundCmd->reconstructPlayList(meta.savegame_version);
+	s->_soundCmd->reconstructPlayList(meta.savegame_version);
 #endif
 
 	// Message state:
-	retval->_msgState = new MessageState(retval->_segMan);
+	s->_msgState = new MessageState(s->_segMan);
 
 #ifdef ENABLE_SCI32
 	if (g_sci->_gui32) {
 		g_sci->_gui32->init();
 	} else {
 #endif
-		g_sci->_gui->resetEngineState(retval);
+		g_sci->_gui->resetEngineState(s);
 		g_sci->_gui->init(g_sci->_features->usesOldGfxFunctions());
 #ifdef ENABLE_SCI32
 	}
 #endif
 
 
-	s->successor = retval; // Set successor
+	s->restoring = true;
 	script_abort_flag = 2; // Abort current game with replay
 	s->shrinkStackToBase();
 }
diff --git a/engines/sci/engine/state.cpp b/engines/sci/engine/state.cpp
index 5325d128be..b642cd8dc9 100644
--- a/engines/sci/engine/state.cpp
+++ b/engines/sci/engine/state.cpp
@@ -72,45 +72,49 @@ static const uint16 s_halfWidthSJISMap[256] = {
 EngineState::EngineState(SegManager *segMan)
 : _segMan(segMan), _dirseeker() {
 
+	reset(false);
+}
+
+EngineState::~EngineState() {
+	delete _msgState;
+}
+
+void EngineState::reset(bool isRestoring) {
 #ifdef USE_OLD_MUSIC_FUNCTIONS
 	sfx_init_flags = 0;
 #endif
 
-	restarting_flags = 0;
+	if (!isRestoring) {
+		script_000 = 0;
+		_gameObj = NULL_REG;
 
-	last_wait_time = 0;
+		_memorySegmentSize = 0;
+		_soundCmd = 0;
 
-	_fileHandles.resize(5);
+		restarting_flags = 0;
 
-	execution_stack_base = 0;
-	_executionStackPosChanged = false;
+		execution_stack_base = 0;
+		_executionStackPosChanged = false;
 
-	r_acc = NULL_REG;
-	restAdjust = 0;
-	r_prev = NULL_REG;
+		_fileHandles.resize(5);
 
-	stack_base = 0;
-	stack_top = 0;
+		r_acc = NULL_REG;
+		restAdjust = 0;
+		r_prev = NULL_REG;
 
-	script_000 = 0;
+		stack_base = 0;
+		stack_top = 0;
+	}
 
-	_gameObj = NULL_REG;
+	last_wait_time = 0;
 
 	gc_countdown = 0;
 
-	successor = 0;
-
 	_throttleCounter = 0;
 	_throttleLastTime = 0;
 	_throttleTrigger = false;
 
-	_memorySegmentSize = 0;
-
-	_soundCmd = 0;
-}
-
-EngineState::~EngineState() {
-	delete _msgState;
+	restoring = false;
 }
 
 void EngineState::wait(int16 ticks) {
diff --git a/engines/sci/engine/state.h b/engines/sci/engine/state.h
index 0746e8e0a8..431aac884e 100644
--- a/engines/sci/engine/state.h
+++ b/engines/sci/engine/state.h
@@ -174,7 +174,12 @@ public:
 	uint _memorySegmentSize;
 	byte _memorySegment[kMemorySegmentMax];
 
-	EngineState *successor; /**< Successor of this state: Used for restoring */
+	/**
+	 * Resets the engine state.
+	 */
+	void reset(bool isRestoring);
+
+	bool restoring;	/**< A flag to indicate if a game is being restored */
 };
 
 } // End of namespace Sci
diff --git a/engines/sci/engine/vm.cpp b/engines/sci/engine/vm.cpp
index 3aee20692a..36f5ec6893 100644
--- a/engines/sci/engine/vm.cpp
+++ b/engines/sci/engine/vm.cpp
@@ -1695,17 +1695,16 @@ static void _init_stack_base_with_selector(EngineState *s, Selector selector) {
 }
 
 static EngineState *_game_run(EngineState *&s) {
-	EngineState *successor = NULL;
-	int game_is_finished = 0;
+	bool restoring = false;
 
 	if (DebugMan.isDebugChannelEnabled(kDebugLevelOnStartup))
 		g_sci->getSciDebugger()->attach();
 
 	do {
 		s->_executionStackPosChanged = false;
-		run_vm(s, successor ? true : false);
+		run_vm(s, restoring);
 		if (s->restarting_flags & SCI_GAME_IS_RESTARTING_NOW) { // Restart was requested?
-			successor = NULL;
+			restoring = false;
 			s->_executionStack.clear();
 			s->_executionStackPosChanged = false;
 
@@ -1723,12 +1722,10 @@ static EngineState *_game_run(EngineState *&s) {
 			s->restarting_flags = SCI_GAME_WAS_RESTARTED;
 
 		} else {
-			successor = s->successor;
-			if (successor) {
+			restoring = s->restoring;
+			if (restoring) {
 				game_exit(s);
-				delete s;
-				s = successor;
-
+				s->restoring = false;
 				if (script_abort_flag == 2) {
 					debugC(2, kDebugLevelVM, "Restarting with replay()");
 					s->_executionStack.clear(); // Restart with replay
@@ -1741,9 +1738,9 @@ static EngineState *_game_run(EngineState *&s) {
 				script_abort_flag = 0;
 
 			} else
-				game_is_finished = 1;
+				break;	// exit loop
 		}
-	} while (!game_is_finished);
+	} while (true);
 
 	return s;
 }