BGE patch: Relink actuators with target within group when duplicating group; generalize protection against object deletion for all actuators that point to objects.

Certain actuators hold a pointer to an objects: Property,
SceneCamera, AddObject, Camera, Parent, TractTo. When a
group is duplicated, the actuators that point to objects
within the group will be relinked to point to the
replicated objects and not to the original objects.
This helps to setup self-contained group with a camera
following a character for example.
This feature also works when adding a single object
(and all its children) with the AddObject actuator.

The second part of the patch extends the protection
against object deletion to all the actuators of the above
list (previously, only the TrackTo, AddObject and
Property actuators were protected). In case the target
object of these actuators is deleted, the BGE won't
crash.

1 files changed, 12 insertions, 0 deletions

diff --git a/source/gameengine/Ketsji/KX_TrackToActuator.cpp b/source/gameengine/Ketsji/KX_TrackToActuator.cpp
index 731a610c2eb..c580aa4d4e5 100644
--- a/source/gameengine/Ketsji/KX_TrackToActuator.cpp
+++ b/source/gameengine/Ketsji/KX_TrackToActuator.cpp
@@ -210,6 +210,18 @@ bool KX_TrackToActuator::UnlinkObject(SCA_IObject* clientobj)
 	return false;
 }
 
+void KX_TrackToActuator::Relink(GEN_Map<GEN_HashedPtr, void*> *obj_map)
+{
+	void **h_obj = (*obj_map)[m_object];
+	if (h_obj) {
+		if (m_object)
+			m_object->UnregisterActuator(this);
+		m_object = (SCA_IObject*)(*h_obj);
+		m_object->RegisterActuator(this);
+	}
+}
+
+
 bool KX_TrackToActuator::Update(double curtime, bool frame)
 {
 	bool result = false;