SCI32: Add workaround for kNumCels

This workaround may be able to be vastly simplified in the future
since, so far, simply returning the number of cels in loop 0 is
enough to make all the scripts with this bug work as expected.

3 files changed, 27 insertions, 2 deletions

diff --git a/engines/sci/engine/workarounds.cpp b/engines/sci/engine/workarounds.cpp
index 85a7966baa..8012b5bffa 100644
--- a/engines/sci/engine/workarounds.cpp
+++ b/engines/sci/engine/workarounds.cpp
@@ -683,6 +683,19 @@ const SciWorkaroundEntry kNewWindow_workarounds[] = {
 };
 
 //    gameID,           room,script,lvl,          object-name, method-name, local-call-signature, index,                workaround
+const SciWorkaroundEntry kNumCels_workarounds[] = {
+	{ GID_GK1,           808, 64998, -1,          "sDJEnters", "changeState",               NULL,    -1, { WORKAROUND_FAKE, 6 } }, //
+	{ GID_GK2,           470, 64998, -1,        "pLookieLoos", "lastCel",                   NULL,    -1, { WORKAROUND_FAKE, 50 } }, // random background movement in the crime scene in Munich city centre
+	{ GID_GK2,           470, 64998, -1,          "pNewsCrew", "lastCel",                   NULL,    -1, { WORKAROUND_FAKE, 18 } }, // random background movement in the crime scene in Munich city centre
+	{ GID_GK2,           470, 64998, -1,        "pLeberGroup", "lastCel",                   NULL,    -1, { WORKAROUND_FAKE, 22 } }, // random background movement in the crime scene in Munich city centre
+	{ GID_SQ6,           270, 64998, -1,           "offWorld", "lastCel",                   NULL,    -1, { WORKAROUND_FAKE, 3 } }, // when exiting the kidnapping room
+	{ GID_SQ6,           320, 64998, -1,          "wandererB", "lastCel",                   NULL,    -1, { WORKAROUND_FAKE, 8 } }, // random background movement on Polysorbate LX street 3
+	{ GID_SQ6,           340, 64998, -1,          "wandererB", "lastCel",                   NULL,    -1, { WORKAROUND_FAKE, 8 } }, // random background movement on Polysorbate LX street 1
+	{ GID_SQ6,           530, 64998, -1,           "monitors", "lastCel",                   NULL,    -1, { WORKAROUND_FAKE, 5 } }, // random background movement during cutscene
+	SCI_WORKAROUNDENTRY_TERMINATOR
+};
+
+//    gameID,           room,script,lvl,          object-name, method-name, local-call-signature, index,                workaround
 const SciWorkaroundEntry kPalVarySetPercent_workarounds[] = {
 	{ GID_GK1,           370,   370,  0,        "graceComeOut", "changeState",              NULL,     0, { WORKAROUND_STILLCALL, 0 } }, // there's an extra parameter in GK1, when changing chapters. This extra parameter seems to be a bug or just unimplemented functionality, as there's no visible change from the original in the chapter change room
 	SCI_WORKAROUNDENTRY_TERMINATOR
diff --git a/engines/sci/engine/workarounds.h b/engines/sci/engine/workarounds.h
index a272baecd9..d1e985dcf1 100644
--- a/engines/sci/engine/workarounds.h
+++ b/engines/sci/engine/workarounds.h
@@ -85,6 +85,7 @@ extern const SciWorkaroundEntry kIsObject_workarounds[];
 extern const SciWorkaroundEntry kMemory_workarounds[];
 extern const SciWorkaroundEntry kMoveCursor_workarounds[];
 extern const SciWorkaroundEntry kNewWindow_workarounds[];
+extern const SciWorkaroundEntry kNumCels_workarounds[];
 extern const SciWorkaroundEntry kPalVarySetPercent_workarounds[];
 extern const SciWorkaroundEntry kRandom_workarounds[];
 extern const SciWorkaroundEntry kReadNumber_workarounds[];
diff --git a/engines/sci/graphics/celobj32.cpp b/engines/sci/graphics/celobj32.cpp
index 5d2d5dd6a6..e5149246e4 100644
--- a/engines/sci/graphics/celobj32.cpp
+++ b/engines/sci/graphics/celobj32.cpp
@@ -28,6 +28,7 @@
 #include "sci/graphics/palette32.h"
 #include "sci/graphics/remap32.h"
 #include "sci/graphics/text32.h"
+#include "sci/engine/workarounds.h"
 
 namespace Sci {
 #pragma mark CelScaler
@@ -819,8 +820,18 @@ int16 CelObjView::getNumCels(const GuiResourceId viewId, const int16 loopNo) {
 	// explicitly trap the bad condition here and report it so that any other
 	// game scripts relying on this broken behavior can be fixed as well
 	if (loopNo == loopCount) {
-		const SciCallOrigin origin = g_sci->getEngineState()->getCurrentCallOrigin();
-		error("[CelObjView::getNumCels]: loop number is equal to loop count in method %s::%s (room %d, script %d, localCall %x)", origin.objectName.c_str(), origin.methodName.c_str(), origin.roomNr, origin.scriptNr, origin.localCallOffset);
+		SciCallOrigin origin;
+		SciWorkaroundSolution solution = trackOriginAndFindWorkaround(0, kNumCels_workarounds, &origin);
+		switch (solution.type) {
+		case WORKAROUND_NONE:
+			error("[CelObjView::getNumCels]: loop number is equal to loop count in method %s::%s (room %d, script %d, localCall %x)", origin.objectName.c_str(), origin.methodName.c_str(), origin.roomNr, origin.scriptNr, origin.localCallOffset);
+		case WORKAROUND_FAKE:
+			return (int16)solution.value;
+		case WORKAROUND_IGNORE:
+			return 0;
+		case WORKAROUND_STILLCALL:
+			break;
+		}
 	}
 
 	if (loopNo > loopCount || loopNo < 0) {