SCUMM: Fix actor ID handling in v0

Some object functions allow actor IDs and object IDs as parameters. They are easily distinguishable in engines > 0 as actor IDs are < _numActors and object IDs are bigger. In v0 this is not the case as there are objects with IDs like 3 and 5 (e.g. the hamster). So object ID handling was unified for v0 and the other engines by introducing objIsActor(), objToActor() and ActorToObj().

7 files changed, 69 insertions, 40 deletions

diff --git a/engines/scumm/debugger.cpp b/engines/scumm/debugger.cpp
index 5d1396633f..edcf2e6fea 100644
--- a/engines/scumm/debugger.cpp
+++ b/engines/scumm/debugger.cpp
@@ -382,8 +382,8 @@ bool ScummDebugger::Cmd_Actor(int argc, const char **argv) {
 			DebugPrintf("Actor[%d].costume = %d\n", actnum, a->_costume);
 		}
 	} else if (!strcmp(argv[2], "name")) {
-		int actor = (_vm->_game.version != 0 ? actnum : OBJECT_V0(actnum, kObjectV0TypeActor));
-		DebugPrintf("Name of actor %d: %s\n", actnum, _vm->getObjOrActorName(actor));
+		DebugPrintf("Name of actor %d: %s\n", actnum, 
+			_vm->getObjOrActorName(_vm->actorToObj(actnum)));
 	} else if (!strcmp(argv[2], "condmask")) {
 		if (argc > 3) {
 			a->_heCondMask = value;
diff --git a/engines/scumm/object.cpp b/engines/scumm/object.cpp
index bf871d7fa5..4ef8707714 100644
--- a/engines/scumm/object.cpp
+++ b/engines/scumm/object.cpp
@@ -357,8 +357,8 @@ int ScummEngine::whereIsObject(int object) const {
 int ScummEngine::getObjectOrActorXY(int object, int &x, int &y) {
 	Actor *act;
 
-	if (object < _numActors) {
-		act = derefActorSafe(object, "getObjectOrActorXY");
+	if (objIsActor(object)) {
+		act = derefActorSafe(objToActor(object), "getObjectOrActorXY");
 		if (act && act->isInCurrentRoom()) {
 			x = act->getRealPos().x;
 			y = act->getRealPos().y;
@@ -371,7 +371,7 @@ int ScummEngine::getObjectOrActorXY(int object, int &x, int &y) {
 	case WIO_NOT_FOUND:
 		return -1;
 	case WIO_INVENTORY:
-		if (_objectOwnerTable[object] < _numActors) {
+		if (objIsActor(_objectOwnerTable[object])) {
 			act = derefActor(_objectOwnerTable[object], "getObjectOrActorXY(2)");
 			if (act && act->isInCurrentRoom()) {
 				x = act->getRealPos().x;
@@ -463,11 +463,11 @@ int ScummEngine::getObjActToObjActDist(int a, int b) {
 	Actor *acta = NULL;
 	Actor *actb = NULL;
 
-	if (a < _numActors)
-		acta = derefActorSafe(a, "getObjActToObjActDist");
+	if (objIsActor(a))
+		acta = derefActorSafe(objToActor(a), "getObjActToObjActDist");
 
-	if (b < _numActors)
-		actb = derefActorSafe(b, "getObjActToObjActDist(2)");
+	if (objIsActor(b))
+		actb = derefActorSafe(objToActor(b), "getObjActToObjActDist(2)");
 
 	if (acta && actb && acta->getRoom() == actb->getRoom() && acta->getRoom() && !acta->isInCurrentRoom())
 		return 0;
@@ -1143,11 +1143,8 @@ const byte *ScummEngine::getObjOrActorName(int obj) {
 	byte *objptr;
 	int i;
 
-	if ((_game.version == 0 && OBJECT_V0_TYPE(obj) == kObjectV0TypeActor) ||
-	    (_game.version != 0 && obj < _numActors)) {
-		int actorNr = (_game.version != 0 ? obj : OBJECT_V0_ID(obj));
-		return derefActor(actorNr, "getObjOrActorName")->getActorName();
-	}
+	if (objIsActor(obj))
+		return derefActor(objToActor(obj), "getObjOrActorName")->getActorName();
 
 	for (i = 0; i < _numNewNames; i++) {
 		if (_newNames[i] == obj) {
@@ -1183,7 +1180,7 @@ const byte *ScummEngine::getObjOrActorName(int obj) {
 void ScummEngine::setObjectName(int obj) {
 	int i;
 
-	if (obj < _numActors && _game.version != 0)
+	if (objIsActor(obj))
 		error("Can't set actor %d name with new-name-of", obj);
 
 	for (i = 0; i < _numNewNames; i++) {
@@ -1491,11 +1488,34 @@ void ScummEngine::findObjectInRoom(FindObjectInRoom *fo, byte findWhat, uint id,
 	}
 }
 
+bool ScummEngine::objIsActor(int obj) {
+	// object IDs < _numActors are used in v0 for objects too (e.g. hamster)
+	if (_game.version == 0)
+		return OBJECT_V0_TYPE(obj) == kObjectV0TypeActor;
+	else
+		return obj < _numActors;
+}
+
+int ScummEngine::objToActor(int obj) {
+	if (_game.version == 0)
+		return OBJECT_V0_ID(obj);
+	else
+		return obj;
+}
+
+int ScummEngine::actorToObj(int actor) {
+	if (_game.version == 0)
+		return OBJECT_V0(actor, kObjectV0TypeActor);
+	else
+		return actor;
+}
+
 int ScummEngine::getObjX(int obj) {
-	if (obj < _numActors) {
-		if (obj < 1)
-			return 0;									/* fix for indy4's map */
-		return derefActor(obj, "getObjX")->getRealPos().x;
+	if (obj < 1)
+		return 0;									/* fix for indy4's map */
+
+	if (objIsActor(obj)) {
+		return derefActor(objToActor(obj), "getObjX")->getRealPos().x;
 	} else {
 		if (whereIsObject(obj) == WIO_NOT_FOUND)
 			return -1;
@@ -1506,10 +1526,11 @@ int ScummEngine::getObjX(int obj) {
 }
 
 int ScummEngine::getObjY(int obj) {
-	if (obj < _numActors) {
-		if (obj < 1)
-			return 0;									/* fix for indy4's map */
-		return derefActor(obj, "getObjY")->getRealPos().y;
+	if (obj < 1)
+		return 0;									/* fix for indy4's map */
+
+	if (objIsActor(obj)) {
+		return derefActor(objToActor(obj), "getObjY")->getRealPos().y;
 	} else {
 		if (whereIsObject(obj) == WIO_NOT_FOUND)
 			return -1;
@@ -1525,8 +1546,8 @@ int ScummEngine::getObjOldDir(int obj) {
 
 int ScummEngine::getObjNewDir(int obj) {
 	int dir;
-	if (obj < _numActors) {
-		dir = derefActor(obj, "getObjNewDir")->getFacing();
+	if (objIsActor(obj)) {
+		dir = derefActor(objToActor(obj), "getObjNewDir")->getFacing();
 	} else {
 		int x, y;
 		getObjectXYPos(obj, x, y, dir);
diff --git a/engines/scumm/script_v0.cpp b/engines/scumm/script_v0.cpp
index b0e3a958e4..7dc8945595 100644
--- a/engines/scumm/script_v0.cpp
+++ b/engines/scumm/script_v0.cpp
@@ -81,7 +81,7 @@ void ScummEngine_v0::setupOpcodes() {
 	/* 24 */
 	OPCODE(0x24, o_ifNotEqualActiveObject2);
 	OPCODE(0x25, o5_loadRoom);
-	OPCODE(0x26, o_getClosestObjActor);
+	OPCODE(0x26, o_getClosestActor);
 	OPCODE(0x27, o2_getActorY);
 	/* 28 */
 	OPCODE(0x28, o5_equalZero);
@@ -161,7 +161,7 @@ void ScummEngine_v0::setupOpcodes() {
 	/* 64 */
 	OPCODE(0x64, o_ifEqualActiveObject2);
 	OPCODE(0x65, o_stopCurrentScript);
-	OPCODE(0x66, o_getClosestObjActor);
+	OPCODE(0x66, o_getClosestActor);
 	OPCODE(0x67, o5_getActorFacing);
 	/* 68 */
 	OPCODE(0x68, o5_isScriptRunning);
@@ -884,31 +884,30 @@ void ScummEngine_v0::o_ifNotEqualActiveObject2() {
 	jumpRelative(!equal);
 }
 
-void ScummEngine_v0::o_getClosestObjActor() {
-	int obj;
-	int act;
+void ScummEngine_v0::o_getClosestActor() {
+	int act, check_act;
 	int dist;
 
 	// This code can't detect any actors farther away than 255 units
 	// (pixels in newer games, characters in older ones.) But this is
 	// perfectly OK, as it is exactly how the original behaved.
 
-	int closest_obj = 0xFF, closest_dist = 0xFF;
+	int closest_act = 0xFF, closest_dist = 0xFF;
 
 	getResultPos();
 
 	act = getVarOrDirectByte(PARAM_1);
-	obj = (_opcode & PARAM_2) ? 25 : 7;
+	check_act = (_opcode & PARAM_2) ? 25 : 7;
 
 	do {
-		dist = getObjActToObjActDist(act, obj);
+		dist = getObjActToObjActDist(actorToObj(act), actorToObj(check_act));
 		if (dist < closest_dist) {
 			closest_dist = dist;
-			closest_obj = obj;
+			closest_act = check_act;
 		}
-	} while (--obj);
+	} while (--check_act);
 
-	setResult(closest_obj);
+	setResult(closest_act);
 }
 
 void ScummEngine_v0::o_cutscene() {
diff --git a/engines/scumm/script_v2.cpp b/engines/scumm/script_v2.cpp
index 6f6138d411..59500deaf5 100644
--- a/engines/scumm/script_v2.cpp
+++ b/engines/scumm/script_v2.cpp
@@ -1315,7 +1315,7 @@ void ScummEngine_v2::o2_getActorX() {
 	getResultPos();
 
 	a = getVarOrDirectByte(PARAM_1);
-	setResult(getObjX(a));
+	setResult(getObjX(actorToObj(a)));
 }
 
 void ScummEngine_v2::o2_getActorY() {
@@ -1323,7 +1323,7 @@ void ScummEngine_v2::o2_getActorY() {
 	getResultPos();
 
 	a = getVarOrDirectByte(PARAM_1);
-	setResult(getObjY(a));
+	setResult(getObjY(actorToObj(a)));
 }
 
 void ScummEngine_v2::o2_isGreater() {
diff --git a/engines/scumm/script_v5.cpp b/engines/scumm/script_v5.cpp
index 707c3c2397..a5591b701f 100644
--- a/engines/scumm/script_v5.cpp
+++ b/engines/scumm/script_v5.cpp
@@ -1095,10 +1095,16 @@ void ScummEngine_v5::o5_getClosestObjActor() {
 void ScummEngine_v5::o5_getDist() {
 	int o1, o2;
 	int r;
+
 	getResultPos();
+	
 	o1 = getVarOrDirectWord(PARAM_1);
 	o2 = getVarOrDirectWord(PARAM_2);
-	r = getObjActToObjActDist(o1, o2);
+
+	if (_game.version == 0) // in v0 both parameters are always actor IDs, never objects
+		r = getObjActToObjActDist(actorToObj(o1), actorToObj(o2));
+	else
+		r = getObjActToObjActDist(o1, o2);
 
 	// FIXME: MI2 race workaround, see bug #597022. We never quite figured out
 	// what the real cause of this, or if it maybe occurs in the original, too...
diff --git a/engines/scumm/scumm.h b/engines/scumm/scumm.h
index fadc3902c0..042a3a5d47 100644
--- a/engines/scumm/scumm.h
+++ b/engines/scumm/scumm.h
@@ -787,6 +787,9 @@ protected:
 	void setOwnerOf(int obj, int owner);
 	void clearOwnerOf(int obj);
 	int getObjectRoom(int obj) const;
+	bool objIsActor(int obj);
+	int objToActor(int obj);
+	int actorToObj(int actor);
 	int getObjX(int obj);
 	int getObjY(int obj);
 	void getObjectXYPos(int object, int &x, int &y)	{ int dir; getObjectXYPos(object, x, y, dir); }
diff --git a/engines/scumm/scumm_v0.h b/engines/scumm/scumm_v0.h
index c5c0c0950c..10ae18ace5 100644
--- a/engines/scumm/scumm_v0.h
+++ b/engines/scumm/scumm_v0.h
@@ -138,7 +138,7 @@ protected:
 	void o_doSentence();
 	void o_ifEqualActiveObject2();
 	void o_ifNotEqualActiveObject2();
-	void o_getClosestObjActor();
+	void o_getClosestActor();
 	void o_printEgo_c64();
 	void o_print_c64();
 	void o_unlockRoom();