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-rw-r--r--engines/agi/agi.h2
-rw-r--r--engines/agi/motion.cpp51
-rw-r--r--engines/agi/op_cmd.cpp12
3 files changed, 65 insertions, 0 deletions
diff --git a/engines/agi/agi.h b/engines/agi/agi.h
index c5db1dfc1d..6540eea0f5 100644
--- a/engines/agi/agi.h
+++ b/engines/agi/agi.h
@@ -926,6 +926,8 @@ private:
void checkMotion(ScreenObjEntry *screenObj);
public:
+ void motionActivated(ScreenObjEntry *screenObj);
+ void cyclerActivated(ScreenObjEntry *screenObj);
void checkAllMotions();
void moveObj(ScreenObjEntry *screenObj);
void inDestination(ScreenObjEntry *screenObj);
diff --git a/engines/agi/motion.cpp b/engines/agi/motion.cpp
index 7f49028701..8aae0e5924 100644
--- a/engines/agi/motion.cpp
+++ b/engines/agi/motion.cpp
@@ -62,6 +62,57 @@ void AgiEngine::changePos(ScreenObjEntry *screenObj) {
}
}
+// WORKAROUND:
+// A motion was just activated, check if "end.of.loop"/"reverse.loop" is currently active for the same screen object
+// If this is the case, it would result in some random flag getting overwritten in original AGI after the loop was
+// completed, because in original AGI loop_flag + move_flag shared the same memory location.
+// This is basically an implementation error in the original interpreter.
+// Happens in at least KQ1, when grabbing the eagle (room 22).
+void AgiEngine::motionActivated(ScreenObjEntry *screenObj) {
+ if (screenObj->flags & fCycling) {
+ // Cycling active too
+ switch (screenObj->cycle) {
+ case kCycleEndOfLoop: // "end.of.loop"
+ case kCycleRevLoop: // "reverse.loop"
+ // Disable it
+ screenObj->flags &= ~fCycling;
+ screenObj->cycle = kCycleNormal;
+
+ warning("Motion activated for screen object %d, but cycler also active", screenObj->objectNr);
+ warning("This would have resulted in flag corruption in original AGI. Cycler disabled.");
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+// WORKAROUND:
+// See comment for motionActivated()
+// This way no flag would have been overwritten, but certain other variables of the motions.
+void AgiEngine::cyclerActivated(ScreenObjEntry *screenObj) {
+ switch (screenObj->motionType) {
+ case kMotionWander:
+ // this would have resulted in wander_count to get corrupted
+ // We don't stop it.
+ break;
+ case kMotionFollowEgo:
+ // this would have resulted in follow_stepSize to get corrupted
+ // do not stop motion atm - screenObj->direction = 0;
+ // do not stop motion atm - screenObj->motionType = kMotionNormal;
+ break;
+ case kMotionMoveObj:
+ // this would have resulted in move_x to get corrupted
+ // do not stop motion atm - motionMoveObjStop(screenObj);
+ break;
+ default:
+ return;
+ break;
+ }
+ warning("Cycler activated for screen object %d, but motion also active", screenObj->objectNr);
+ warning("This would have resulted in corruption in original AGI. Motion disabled.");
+}
+
void AgiEngine::motionWander(ScreenObjEntry *screenObj) {
uint8 originalWanderCount = screenObj->wander_count;
diff --git a/engines/agi/op_cmd.cpp b/engines/agi/op_cmd.cpp
index 8ee9958ecd..0e0f49b542 100644
--- a/engines/agi/op_cmd.cpp
+++ b/engines/agi/op_cmd.cpp
@@ -1495,6 +1495,8 @@ void cmdReverseLoop(AgiGame *state, AgiEngine *vm, uint8 *parameter) {
screenObj->flags |= (fDontupdate | fUpdate | fCycling);
screenObj->loop_flag = loopFlag;
state->_vm->setFlag(screenObj->loop_flag, false);
+
+ vm->cyclerActivated(screenObj);
}
void cmdReverseLoopV1(AgiGame *state, AgiEngine *vm, uint8 *parameter) {
@@ -1520,6 +1522,8 @@ void cmdEndOfLoop(AgiGame *state, AgiEngine *vm, uint8 *parameter) {
screenObj->flags |= (fDontupdate | fUpdate | fCycling);
screenObj->loop_flag = loopFlag;
vm->setFlag(screenObj->loop_flag, false);
+
+ vm->cyclerActivated(screenObj);
}
void cmdEndOfLoopV1(AgiGame *state, AgiEngine *vm, uint8 *parameter) {
@@ -1632,6 +1636,8 @@ void cmdFollowEgo(AgiGame *state, AgiEngine *vm, uint8 *parameter) {
vm->setFlag(screenObj->follow_flag, false);
screenObj->flags |= fUpdate;
}
+
+ vm->motionActivated(screenObj);
}
void cmdMoveObj(AgiGame *state, AgiEngine *vm, uint8 *parameter) {
@@ -1660,6 +1666,8 @@ void cmdMoveObj(AgiGame *state, AgiEngine *vm, uint8 *parameter) {
screenObj->flags |= fUpdate;
}
+ vm->motionActivated(screenObj);
+
if (objectNr == 0)
state->playerControl = false;
@@ -1688,6 +1696,8 @@ void cmdMoveObjF(AgiGame *state, AgiEngine *vm, uint8 *parameter) {
vm->setFlag(screenObj->move_flag, false);
screenObj->flags |= fUpdate;
+ vm->motionActivated(screenObj);
+
if (objectNr == 0)
state->playerControl = false;
@@ -1709,6 +1719,8 @@ void cmdWander(AgiGame *state, AgiEngine *vm, uint8 *parameter) {
} else {
screenObj->flags |= fUpdate;
}
+
+ vm->motionActivated(screenObj);
}
void cmdSetGameID(AgiGame *state, AgiEngine *vm, uint8 *parameter) {