From 35daa692aff1cb2d6aa0cbca3480fa8c50be55c6 Mon Sep 17 00:00:00 2001
From: Thanasis Antoniou <a.antoniou79@gmail.com>
Date: Fri, 31 May 2019 16:42:31 +0300
Subject: [PATCH] BLADERUNNER: Fix bad timer initialization for actors after
 LOAD

---
 engines/bladerunner/actor.cpp       |  3 +++
 engines/bladerunner/bladerunner.cpp | 17 ++++++++++++++++-
 engines/bladerunner/time.cpp        |  9 +++++++++
 engines/bladerunner/time.h          |  1 +
 4 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/engines/bladerunner/actor.cpp b/engines/bladerunner/actor.cpp
index 1c87d8e668e5..dd5650c32443 100644
--- a/engines/bladerunner/actor.cpp
+++ b/engines/bladerunner/actor.cpp
@@ -255,7 +255,9 @@ void Actor::timerUpdate(int timerId) {
 	if (_timersLeft[timerId] <= 0) {
 		switch (timerId) {
 		case kActorTimerAIScriptCustomTask0:
+			// fall through
 		case kActorTimerAIScriptCustomTask1:
+			// fall through
 		case kActorTimerAIScriptCustomTask2:
 			if (!_vm->_aiScripts->isInsideScript() && !_vm->_sceneScript->isInsideScript()) {
 				_vm->_aiScripts->timerExpired(_id, timerId);
@@ -1397,6 +1399,7 @@ void Actor::save(SaveFileWriteStream &f) {
 
 	uint32 now = _vm->_time->getPauseStart();
 	for (int i = 0; i < kActorTimers; ++i) {
+		// this effectively stores the next timeDiff to be applied to timer i (in timerUpdate)
 		f.writeInt(now - _timersLast[i]);
 	}
 
diff --git a/engines/bladerunner/bladerunner.cpp b/engines/bladerunner/bladerunner.cpp
index 6fc8dda67c59..3d20423c39d0 100644
--- a/engines/bladerunner/bladerunner.cpp
+++ b/engines/bladerunner/bladerunner.cpp
@@ -254,7 +254,12 @@ Common::Error BladeRunnerEngine::loadGameState(int slot) {
 	if (!BladeRunner::SaveFileManager::readHeader(*saveFile, header)) {
 		error("Invalid savegame");
 	}
+
 	setTotalPlayTime(header._playTime);
+	// this essentially does something similar with setTotalPlayTime
+	// reseting and updating Blade Runner's _pauseStart and offset before starting a loaded game
+	_time->resetPauseStart();
+
 	loadGame(*saveFile);
 
 	delete saveFile;
@@ -336,8 +341,17 @@ Common::Error BladeRunnerEngine::run() {
 			// end of additional code for gracefully handling end-game
 
 			if (ConfMan.hasKey("save_slot") && ConfMan.getInt("save_slot") != -1) {
+				// when loading from ScummVM main menu, we should emulate
+				// the Kia pause/resume in order to get a valid "current" time when the game
+				// is actually loaded (assuming delays can be introduced by a popup warning dialogue)
+				if(!_time->isLocked()) {
+					_time->pause();
+				}
 				loadGameState(ConfMan.getInt("save_slot"));
 				ConfMan.set("save_slot", "-1");
+				if(_time->isLocked()) {
+					_time->resume();
+				}
 			} else if (hasSavegames) {
 				_kia->_forceOpen = true;
 				_kia->open(kKIASectionLoad);
@@ -402,7 +416,6 @@ bool BladeRunnerEngine::startup(bool hasSavegames) {
 	_surfaceBack.create(640, 480, screenPixelFormat());
 
 	_time = new Time(this);
-
 	// Try to load the SUBTITLES.MIX first, before Startup.MIX
 	// allows overriding any identically named resources (such as the original font files and as a bonus also the TRE files for the UI and dialogue menu)
 	_subtitles = new Subtitles(this);
@@ -972,6 +985,8 @@ void BladeRunnerEngine::gameTick() {
 	_overlays->tick();
 
 	if (!inDialogueMenu) {
+		// TODO This is probably responsible for actors getting stuck in place
+		// after reaching a waypoint when dialoge menu is open
 		actorsUpdate();
 	}
 
diff --git a/engines/bladerunner/time.cpp b/engines/bladerunner/time.cpp
index 5d82a0cd551f..ff7b6a78b552 100644
--- a/engines/bladerunner/time.cpp
+++ b/engines/bladerunner/time.cpp
@@ -70,4 +70,13 @@ bool Time::isLocked() {
 	return _pauseCount > 0;
 }
 
+// To be called before loading a new game, since
+// the offset should be reset to zero and _pauseStart should be current() (ie currentSystem() - _start)
+// TODO Explore if it would make sense to only use the Engine methods for time accounting (pauseEngine, get/setTotalPlatTime)
+//      or do we need separated/independent time accounting and pausing?
+void Time::resetPauseStart() {
+	_offset = 0;
+	_pauseStart = current();
+}
+
 } // End of namespace BladeRunner
diff --git a/engines/bladerunner/time.h b/engines/bladerunner/time.h
index 4e372ea05fd7..48fa23a59420 100644
--- a/engines/bladerunner/time.h
+++ b/engines/bladerunner/time.h
@@ -44,6 +44,7 @@ class Time {
 	int  getPauseStart();
 	int  resume();
 	bool isLocked();
+	void resetPauseStart();
 };
 
 } // End of namespace BladeRunner