SCI: Throttle the invocations of Engine::shouldQuit()

SCI constantly invoked Engine::shouldQuit(), which in
turn called 2 virtual functions. This added a significant
overhead, as this was called constantly without any
throttling whatsoever. Now, the invocation of shouldQuit()
is throttled to be on each frame update (i.e. at a rate of
60fps). Thanks to wjp for profiling this.

svn-id: r52431

1 files changed, 10 insertions, 2 deletions

diff --git a/engines/sci/event.cpp b/engines/sci/event.cpp
index acd2e9f735..5d469eda7b 100644
--- a/engines/sci/event.cpp
+++ b/engines/sci/event.cpp
@@ -351,9 +351,17 @@ SciEvent EventManager::getScummVMEvent() {
 void EventManager::updateScreen() {
 	// Update the screen here, since it's called very often.
 	// Throttle the screen update rate to 60fps.
-	if (g_system->getMillis() - g_sci->getEngineState()->_screenUpdateTime >= 1000 / 60) {
+	EngineState *s = g_sci->getEngineState();
+	if (g_system->getMillis() - s->_screenUpdateTime >= 1000 / 60) {
 		g_system->updateScreen();
-		g_sci->getEngineState()->_screenUpdateTime = g_system->getMillis();
+		s->_screenUpdateTime = g_system->getMillis();
+		// Throttle the checking of shouldQuit() to 60fps as well, since 
+		// Engine::shouldQuit() invokes 2 virtual functions
+		// (EventManager::shouldQuit() and EventManager::shouldRTL()),
+		// which is very expensive to invoke constantly without any
+		// throttling at all.
+		if (g_engine->shouldQuit())
+			s->abortScriptProcessing = kAbortQuitGame;
 	}
 }