thirdparty/scummvm
2
0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

AGI: Add detection+workaround for endofloop+motion at the same time

Browse source 
Detects when end.of.loop + motions are used on the same screen
object at the same time, which would have resulted in flag
corruption in the original interpreter. We detect this
situation now, show a warning and disable the cycler in case
cycler was activated first.
This solves a new issue in kq1, when grabbing the eagle in room
22, that was previously hidden just like in the original AGI.
Fixes bug #7046
This commit is contained in:
Martin Kiewitz 2016-02-19 10:34:37 +01:00
parent 1c4778d571
commit 5484f0bc58
3 changed files with 65 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

2
engines/agi/agi.h
View file

@ -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);

51
engines/agi/motion.cpp
View file

@ -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;

12
engines/agi/op_cmd.cpp
View file

@ -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) {