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, 49 insertions, 13 deletions

diff --git a/source/gameengine/Ketsji/KX_CameraActuator.cpp b/source/gameengine/Ketsji/KX_CameraActuator.cpp
index 27f4870de10..0a97b6f0a2f 100644
--- a/source/gameengine/Ketsji/KX_CameraActuator.cpp
+++ b/source/gameengine/Ketsji/KX_CameraActuator.cpp
@@ -49,7 +49,7 @@ STR_String KX_CameraActuator::Y_AXIS_STRING = "y";
 
 KX_CameraActuator::KX_CameraActuator(
 	SCA_IObject* gameobj, 
-	CValue *obj,
+	SCA_IObject *obj,
 	MT_Scalar hght,
 	MT_Scalar minhght,
 	MT_Scalar maxhght,
@@ -63,11 +63,14 @@ KX_CameraActuator::KX_CameraActuator(
 	m_maxHeight (maxhght),
 	m_x (xytog)
 {
+	if (m_ob)
+		m_ob->RegisterActuator(this);
 }
 
 KX_CameraActuator::~KX_CameraActuator()
 {
-	//nothing to do
+	if (m_ob)
+		m_ob->UnregisterActuator(this);
 }
 
 	CValue* 
@@ -81,9 +84,36 @@ GetReplica(
 	return replica;
 };
 
+void KX_CameraActuator::ProcessReplica()
+{
+	if (m_ob)
+		m_ob->RegisterActuator(this);
+	SCA_IActuator::ProcessReplica();
+}
 
+bool KX_CameraActuator::UnlinkObject(SCA_IObject* clientobj)
+{
+	if (clientobj == m_ob)
+	{
+		// this object is being deleted, we cannot continue to track it.
+		m_ob = NULL;
+		return true;
+	}
+	return false;
+}
 
 
+void KX_CameraActuator::Relink(GEN_Map<GEN_HashedPtr, void*> *obj_map)
+{
+	void **h_obj = (*obj_map)[m_ob];
+	if (h_obj) {
+		if (m_ob)
+			m_ob->UnregisterActuator(this);
+		m_ob = (SCA_IObject*)(*h_obj);
+		m_ob->RegisterActuator(this);
+	}
+}
+
 /* three functions copied from blender arith... don't know if there's an equivalent */
 
 static float Kx_Normalize(float *n)
@@ -181,8 +211,14 @@ static void Kx_VecUpMat3(float *vec, float mat[][3], short axis)
 
 bool KX_CameraActuator::Update(double curtime, bool frame)
 {
-	bool result = true;
+	/* wondering... is it really neccesary/desirable to suppress negative    */
+	/* events here?                                                          */
+	bool bNegativeEvent = IsNegativeEvent();
+	RemoveAllEvents();
 
+	if (bNegativeEvent || !m_ob) 
+		return false;
+	
 	KX_GameObject *obj = (KX_GameObject*) GetParent();
 	MT_Point3 from = obj->NodeGetWorldPosition();
 	MT_Matrix3x3 frommat = obj->NodeGetWorldOrientation();
@@ -195,13 +231,6 @@ bool KX_CameraActuator::Update(double curtime, bool frame)
 	float mindistsq, maxdistsq, distsq;
 	float mat[3][3];
 	
-	/* wondering... is it really neccesary/desirable to suppress negative    */
-	/* events here?                                                          */
-	bool bNegativeEvent = IsNegativeEvent();
-	RemoveAllEvents();
-
-	if (bNegativeEvent) return false;
-	
 	/* The rules:                                                            */
 	/* CONSTRAINT 1: not implemented */
 	/* CONSTRAINT 2: can camera see actor?              */
@@ -315,7 +344,7 @@ bool KX_CameraActuator::Update(double curtime, bool frame)
 	actormat[2][0]= mat[0][2]; actormat[2][1]= mat[1][2]; actormat[2][2]= mat[2][2];
 	obj->NodeSetLocalOrientation(actormat);
 
-	return result;
+	return true;
 }
 
 CValue *KX_CameraActuator::findObject(char *obName) 
@@ -404,7 +433,11 @@ PyObject* KX_CameraActuator::PySetObject(PyObject* self,
 	PyObject* gameobj;
 	if (PyArg_ParseTuple(args, "O!", &KX_GameObject::Type, &gameobj))
 	{
-		m_ob = (CValue*)gameobj;
+		if (m_ob)
+			m_ob->UnregisterActuator(this);
+		m_ob = (SCA_IObject*)gameobj;
+		if (m_ob)
+			m_ob->RegisterActuator(this);
 		Py_Return;
 	}
 	PyErr_Clear();
@@ -412,10 +445,13 @@ PyObject* KX_CameraActuator::PySetObject(PyObject* self,
 	char* objectname;
 	if (PyArg_ParseTuple(args, "s", &objectname))
 	{
-		CValue *object = (CValue*)SCA_ILogicBrick::m_sCurrentLogicManager->GetGameObjectByName(STR_String(objectname));
+		SCA_IObject *object = (SCA_IObject*)SCA_ILogicBrick::m_sCurrentLogicManager->GetGameObjectByName(STR_String(objectname));
 		if(object)
 		{
+			if (m_ob != NULL)
+				m_ob->UnregisterActuator(this);
 			m_ob = object;
+			m_ob->RegisterActuator(this);
 			Py_Return;
 		}
 	}