Ticket #5793: ihnm-pathfinder-workaround.txt

diff --git a/engines/saga/actor_path.cpp b/engines/saga/actor_path.cpp
index 0fb072b..d0f1cf2 100644
--- a/engines/saga/actor_path.cpp
+++ b/engines/saga/actor_path.cpp
@@ -23,6 +23,7 @@
 #include "saga/saga.h"
 
 #include "saga/actor.h"
+#include "saga/objectmap.h"
 #include "saga/scene.h"
 
 namespace Saga {
@@ -99,6 +100,47 @@ void Actor::findActorPath(ActorData *actor, const Point &fromPoint, const Point
        _debugPointsCount = 0;
 #endif
 
+       // WORKAROUND for bug #3360396. Path finding in IHNM is a bit buggy
+       // compared to the original, which occasionally leads to the player
+       // leaving the room instead of interacting with an object. So far, no
+       // one has figured out how to fix this properly. As a temporary [*]
+       // solution, we try to fix this on a case-by-case basis.
+       //
+       // The workaround is to assume that the player wants to stay in the
+       // room, unless he or she explicitly clicked on an exit zone.
+       //
+       // [*] And there is nothing more permanent than a temporary solution...
+
+       bool pathFindingWorkaround = false;
+
+       if (_vm->getGameId() == GID_IHNM) {
+               int chapter = _vm->_scene->currentChapterNumber();
+               int scene = _vm->_scene->currentSceneNumber();
+
+               // Ellen, in the room with the monitors.
+               if (chapter == 3 && scene == 54)
+                       pathFindingWorkaround = true;
+
+               // Nimdok in the recovery room
+               if (chapter == 4 && scene == 71)
+                       pathFindingWorkaround = true;
+       }
+
+       int hitZoneIndex;
+       const HitZone *hitZone;
+       bool restrictToRoom = false;
+
+       if (pathFindingWorkaround) {
+               restrictToRoom = true;
+               hitZoneIndex = _vm->_scene->_actionMap->hitTest(toPoint);
+               if (hitZoneIndex != -1) {
+                       hitZone = _vm->_scene->_actionMap->getHitZone(hitZoneIndex);
+                       if (hitZone->getFlags() & kHitZoneExit) {
+                               restrictToRoom = false;
+                       }
+               }
+       }
+
        actor->_walkStepsCount = 0;
        if (fromPoint == toPoint) {
                actor->addWalkStepPoint(toPoint);
@@ -110,6 +152,15 @@ void Actor::findActorPath(ActorData *actor, const Point &fromPoint, const Point
                        if (_vm->_scene->validBGMaskPoint(iteratorPoint)) {
                                maskType = _vm->_scene->getBGMaskType(iteratorPoint);
                                setPathCell(iteratorPoint, _vm->_scene->getDoorState(maskType) ? kPathCellBarrier : kPathCellEmpty);
+                               if (restrictToRoom) {
+                                       hitZoneIndex = _vm->_scene->_actionMap->hitTest(iteratorPoint);
+                                       if (hitZoneIndex != -1) {
+                                               hitZone = _vm->_scene->_actionMap->getHitZone(hitZoneIndex);
+                                               if (hitZone->getFlags() & kHitZoneExit) {
+                                                       setPathCell(iteratorPoint, kPathCellBarrier);
+                                               }
+                                       }
+                               }
                        } else {
                                setPathCell(iteratorPoint, kPathCellBarrier);
                        }