SCI: Replace magic numbers for globals with named constants

7 files changed, 31 insertions, 16 deletions

diff --git a/engines/sci/engine/kscripts.cpp b/engines/sci/engine/kscripts.cpp
index 6fd130bceb..749af67580 100644
--- a/engines/sci/engine/kscripts.cpp
+++ b/engines/sci/engine/kscripts.cpp
@@ -238,8 +238,8 @@ reg_t kScriptID(EngineState *s, int argc, reg_t *argv) {
 	// initialized to 0, whereas it's 6 in other versions. Thus, we assign it
 	// to 6 here, fixing the speed of the introduction. Refer to bug #3102071.
 	if (g_sci->getGameId() == GID_PQ2 && script == 200 &&
-		s->variables[VAR_GLOBAL][3].isNull()) {
-		s->variables[VAR_GLOBAL][3] = make_reg(0, 6);
+		s->variables[VAR_GLOBAL][kSpeed].isNull()) {
+		s->variables[VAR_GLOBAL][kSpeed] = make_reg(0, 6);
 	}
 
 	return make_reg(scriptSeg, address);
diff --git a/engines/sci/engine/state.cpp b/engines/sci/engine/state.cpp
index d253d316ca..5d4eba7c95 100644
--- a/engines/sci/engine/state.cpp
+++ b/engines/sci/engine/state.cpp
@@ -159,11 +159,11 @@ void EngineState::initGlobals() {
 }
 
 uint16 EngineState::currentRoomNumber() const {
-	return variables[VAR_GLOBAL][13].toUint16();
+	return variables[VAR_GLOBAL][kNewRoomNo].toUint16();
 }
 
 void EngineState::setRoomNumber(uint16 roomNumber) {
-	variables[VAR_GLOBAL][13] = make_reg(0, roomNumber);
+	variables[VAR_GLOBAL][kNewRoomNo] = make_reg(0, roomNumber);
 }
 
 void EngineState::shrinkStackToBase() {
diff --git a/engines/sci/engine/vm.cpp b/engines/sci/engine/vm.cpp
index 72e340dd5c..7c7f75c180 100644
--- a/engines/sci/engine/vm.cpp
+++ b/engines/sci/engine/vm.cpp
@@ -179,7 +179,7 @@ static void write_var(EngineState *s, int type, int index, reg_t value) {
 		// stopGroop object, which points to ego, to the new ego object. If this is not
 		// done, ego's movement will not be updated properly, so the result is
 		// unpredictable (for example in LSL5, Patti spins around instead of walking).
-		if (index == 0 && type == VAR_GLOBAL && getSciVersion() > SCI_VERSION_0_EARLY) {	// global 0 is ego
+		if (index == kEgo && type == VAR_GLOBAL && getSciVersion() > SCI_VERSION_0_EARLY) {
 			reg_t stopGroopPos = s->_segMan->findObjectByName("stopGroop");
 			if (!stopGroopPos.isNull()) {	// does the game have a stopGroop object?
 				// Find the "client" member variable of the stopGroop object, and update it
@@ -200,9 +200,9 @@ static void write_var(EngineState *s, int type, int index, reg_t value) {
 
 		s->variables[type][index] = value;
 
-		if (type == VAR_GLOBAL && index == 90) {
+		if (type == VAR_GLOBAL && index == kMessageType) {
 			// The game is trying to change its speech/subtitle settings
-			if (!g_sci->getEngineState()->_syncedAudioOptions || s->variables[VAR_GLOBAL][4] == TRUE_REG) {
+			if (!g_sci->getEngineState()->_syncedAudioOptions || s->variables[VAR_GLOBAL][kQuit] == TRUE_REG) {
 				// ScummVM audio options haven't been applied yet, so apply them.
 				// We also force the ScummVM audio options when loading a game from
 				// the launcher.
diff --git a/engines/sci/engine/vm.h b/engines/sci/engine/vm.h
index c41060dc32..e127706d58 100644
--- a/engines/sci/engine/vm.h
+++ b/engines/sci/engine/vm.h
@@ -136,6 +136,21 @@ enum {
 	VAR_PARAM = 3
 };
 
+enum GlobalVar {
+	kEgo            = 0,
+	kGame           = 1,
+	kCurrentRoom    = 2,
+	kSpeed          = 3,  // SCI16
+	kDefaultPlane   = 3,  // SCI32
+	kQuit           = 4,
+	kPlanes         = 10, // SCI32
+	kCurrentRoomNo  = 11,
+	kPreviousRoomNo = 12,
+	kNewRoomNo      = 13,
+	kFastCast       = 84, // SCI16
+	kMessageType    = 90
+};
+
 /** Number of kernel calls in between gcs; should be < 50000 */
 enum {
 	GC_INTERVAL = 0x8000
diff --git a/engines/sci/graphics/animate.cpp b/engines/sci/graphics/animate.cpp
index 98278397b7..e593484d8b 100644
--- a/engines/sci/graphics/animate.cpp
+++ b/engines/sci/graphics/animate.cpp
@@ -145,7 +145,7 @@ bool GfxAnimate::invoke(List *list, int argc, reg_t *argv) {
 		if (_fastCastEnabled) {
 			// Check if the game has a fastCast object set
 			//  if we don't abort kAnimate processing, at least in kq5 there will be animation cels drawn into speech boxes.
-			if (!_s->variables[VAR_GLOBAL][84].isNull()) {
+			if (!_s->variables[VAR_GLOBAL][kFastCast].isNull()) {
 				// This normally points to an object called "fastCast",
 				// but for example in Eco Quest 1 it may also point to an object called "EventHandler" (see bug #5170)
 				// Original SCI only checked, if this global was not 0.
@@ -338,7 +338,7 @@ void GfxAnimate::applyGlobalScaling(AnimateList::iterator entry, GfxView *view)
 	int16 maxScale = readSelectorValue(_s->_segMan, entry->object, SELECTOR(maxScale));
 	int16 celHeight = view->getHeight(entry->loopNo, entry->celNo);
 	int16 maxCelHeight = (maxScale * celHeight) >> 7;
-	reg_t globalVar2 = _s->variables[VAR_GLOBAL][2]; // current room object
+	reg_t globalVar2 = _s->variables[VAR_GLOBAL][kCurrentRoom]; // current room object
 	int16 vanishingY = readSelectorValue(_s->_segMan, globalVar2, SELECTOR(vanishingY));
 
 	int16 fixedPortY = _ports->getPort()->rect.bottom - vanishingY;
diff --git a/engines/sci/graphics/frameout.cpp b/engines/sci/graphics/frameout.cpp
index 7d38d01f02..7410bdabac 100644
--- a/engines/sci/graphics/frameout.cpp
+++ b/engines/sci/graphics/frameout.cpp
@@ -141,7 +141,7 @@ void GfxFrameout::syncWithScripts(bool addElements) {
 		return;
 
 	// Get planes list object
-	reg_t planesListObject = engineState->variables[VAR_GLOBAL][10];
+	reg_t planesListObject = engineState->variables[VAR_GLOBAL][kPlanes];
 	reg_t planesListElements = readSelector(segMan, planesListObject, SELECTOR(elements));
 
 	List *planesList = segMan->lookupList(planesListElements);
@@ -565,7 +565,7 @@ void GfxFrameout::palMorphFrameOut(const int8 *styleRanges, PlaneShowStyle *show
 	Palette sourcePalette(_palette->getNextPalette());
 	alterVmap(sourcePalette, sourcePalette, -1, styleRanges);
 
-	int16 prevRoom = g_sci->getEngineState()->variables[VAR_GLOBAL][12].toSint16();
+	int16 prevRoom = g_sci->getEngineState()->variables[VAR_GLOBAL][kPreviousRoomNo].toSint16();
 
 	Common::Rect rect(_currentBuffer.screenWidth, _currentBuffer.screenHeight);
 	_showList.add(rect);
diff --git a/engines/sci/sci.cpp b/engines/sci/sci.cpp
index eb314a9208..bdfb6ccc9c 100644
--- a/engines/sci/sci.cpp
+++ b/engines/sci/sci.cpp
@@ -1088,9 +1088,9 @@ void SciEngine::syncIngameAudioOptions() {
 
 		if (useGlobal90) {
 			if (subtitlesOn && !speechOn) {
-				_gamestate->variables[VAR_GLOBAL][90] = make_reg(0, 1);	// subtitles
+				_gamestate->variables[VAR_GLOBAL][kMessageType] = make_reg(0, 1);	// subtitles
 			} else if (!subtitlesOn && speechOn) {
-				_gamestate->variables[VAR_GLOBAL][90] = make_reg(0, 2);	// speech
+				_gamestate->variables[VAR_GLOBAL][kMessageType] = make_reg(0, 2);	// speech
 			} else if (subtitlesOn && speechOn) {
 				// Is it a game that supports simultaneous speech and subtitles?
 				switch (_gameId) {
@@ -1111,11 +1111,11 @@ void SciEngine::syncIngameAudioOptions() {
 				// Phantasmagoria does not support simultaneous speech + subtitles
 				// Mixed Up Mother Goose Deluxe does not support simultaneous speech + subtitles
 #endif // ENABLE_SCI32
-					_gamestate->variables[VAR_GLOBAL][90] = make_reg(0, 3);	// speech + subtitles
+					_gamestate->variables[VAR_GLOBAL][kMessageType] = make_reg(0, 3);	// speech + subtitles
 					break;
 				default:
 					// Game does not support speech and subtitles, set it to speech
-					_gamestate->variables[VAR_GLOBAL][90] = make_reg(0, 2);	// speech
+					_gamestate->variables[VAR_GLOBAL][kMessageType] = make_reg(0, 2);	// speech
 				}
 			}
 		}
@@ -1126,7 +1126,7 @@ void SciEngine::updateScummVMAudioOptions() {
 	// Update ScummVM's speech/subtitles settings for SCI1.1 CD games,
 	// depending on the in-game settings
 	if (isCD() && getSciVersion() == SCI_VERSION_1_1) {
-		uint16 ingameSetting = _gamestate->variables[VAR_GLOBAL][90].getOffset();
+		uint16 ingameSetting = _gamestate->variables[VAR_GLOBAL][kMessageType].getOffset();
 
 		switch (ingameSetting) {
 		case 1: