#510: Fix disappearing AIShips.

Untangle AI reinit and init methods. Some code in init hooks expects to be
called once only. Derived classes should not redirect their reinit to init,
even if this seems fine for the methods of the derived class itself. This
also triggers the init methods of all base classes, which may not expect
multiple calls to their init methods (or to "init" on "reinit").

src/AIModel/AIBallistic.cxx

@@ -126,7 +126,11 @@ void FGAIBallistic::readFromScenario(SGPropertyNode* scFileNode) {
 
 bool FGAIBallistic::init(bool search_in_AI_path) {
     FGAIBase::init(search_in_AI_path);
+    reinit();
+    return true;
+}
 
+void FGAIBallistic::reinit() {
     _impact_reported = false;
     _collision_reported = false;
     _expiry_reported = false;
@@ -179,7 +183,7 @@ bool FGAIBallistic::init(bool search_in_AI_path) {
 
     setParentNodes(_selected_ac);
 
-    return true;
+    FGAIBase::reinit();
 }
 
 void FGAIBallistic::bind() {

src/AIModel/AIBallistic.hxx

@@ -46,10 +46,10 @@ public:
     bool init(bool search_in_AI_path=false);
     virtual void bind();
     virtual void unbind();
+    virtual void reinit();
+    virtual void update(double dt);
 
-    void update(double dt);
-
-    FGAIBallistic *ballistic;
+    virtual const char* getTypeString(void) const { return "ballistic"; }
 
     void Run(double dt);
 
@@ -114,7 +114,8 @@ public:
 //    bool getFormate() const;
     bool getSlavedLoad() const;
 
-    virtual const char* getTypeString(void) const { return "ballistic"; }
+    FGAIBallistic *ballistic;
+
     static const double slugs_to_kgs; //conversion factor
     static const double slugs_to_lbs; //conversion factor
 
@@ -170,8 +171,6 @@ public:
 
 private:
 
-    virtual void reinit() { init(); }
-
     bool   _aero_stabilised; // if true, object will align with trajectory
     double _drag_area;       // equivalent drag area in ft2
     double _life_timer;      // seconds

src/AIModel/AIBase.cxx

@@ -288,8 +288,14 @@ void FGAIBase::Transform() {
 
 }
 
-bool FGAIBase::init(bool search_in_AI_path) {
-    
+bool FGAIBase::init(bool search_in_AI_path)
+{
+    if (_model.valid())
+    {
+        SG_LOG(SG_AI, SG_WARN, "AIBase: Cannot initialize a model multiple times! " << model_path);
+        return false;
+    }
+
     string f;
     if(search_in_AI_path)
     {
@@ -318,12 +324,6 @@ bool FGAIBase::init(bool search_in_AI_path) {
     _aimodel = new FGAIModelData(props);
     osg::Node * mdl = SGModelLib::loadDeferredModel(f, props, _aimodel);
 
-    if (_model.valid())
-    {
-        // reinit, dump the old model
-        removeModel();
-    }
-
     _model = new osg::LOD;
     _model->setName("AI-model range animation node");
 

src/AIModel/AIEscort.cxx

@@ -134,7 +134,11 @@ void FGAIEscort::unbind() {
 bool FGAIEscort::init(bool search_in_AI_path) {
     if (!FGAIShip::init(search_in_AI_path))
         return false;
+    reinit();
+    return true;
+}
 
+void FGAIEscort::reinit() {
     invisible = false;
     no_roll = false;
 
@@ -147,7 +151,7 @@ bool FGAIEscort::init(bool search_in_AI_path) {
         hdg = _parent_hdg;
     }
 
-    return true;
+    FGAIShip::reinit();
 }
 
 void FGAIEscort::update(double dt) {

src/AIModel/AIEscort.hxx

@@ -39,17 +39,16 @@ public:
     virtual ~FGAIEscort();
 
     virtual void readFromScenario(SGPropertyNode* scFileNode);
-    virtual void bind();
-    virtual void unbind();
-    virtual const char* getTypeString(void) const { return "escort"; }
 
     bool init(bool search_in_AI_path=false);
-
-private:
-
-    virtual void reinit() { init(); }
+    virtual void bind();
+    virtual void unbind();
+    virtual void reinit();
     virtual void update (double dt);
 
+    virtual const char* getTypeString(void) const { return "escort"; }
+
+private:
     void setStnRange(double r);
     void setStnBrg(double y);
     void setStationSpeed();

src/AIModel/AIGroundVehicle.cxx

@@ -142,7 +142,11 @@ void FGAIGroundVehicle::unbind() {
 bool FGAIGroundVehicle::init(bool search_in_AI_path) {
     if (!FGAIShip::init(search_in_AI_path))
         return false;
+    reinit();
+    return true;
+}
 
+void FGAIGroundVehicle::reinit() {
     invisible = false;
     _limit = 200;
     no_roll = true;
@@ -162,7 +166,7 @@ bool FGAIGroundVehicle::init(bool search_in_AI_path) {
         setParent();
     }
 
-    return true;
+    FGAIShip::reinit();
 }
 
 void FGAIGroundVehicle::update(double dt) {

src/AIModel/AIGroundVehicle.hxx

@@ -37,17 +37,17 @@ public:
     virtual ~FGAIGroundVehicle();
 
     virtual void readFromScenario(SGPropertyNode* scFileNode);
-    virtual void bind();
-    virtual void unbind();
-    virtual const char* getTypeString(void) const { return "groundvehicle"; }
 
     bool init(bool search_in_AI_path=false);
+    virtual void bind();
+    virtual void unbind();
+    virtual void reinit();
+    virtual void update (double dt);
+
+    virtual const char* getTypeString(void) const { return "groundvehicle"; }
 
 private:
 
-    virtual void reinit() { init(); }
-    virtual void update (double dt);
-
     void setNoRoll(bool nr);
     void setContactX1offset(double x1);
     void setContactX2offset(double x2);

src/AIModel/AIShip.cxx

@@ -113,6 +113,12 @@ void FGAIShip::readFromScenario(SGPropertyNode* scFileNode) {
 }
 
 bool FGAIShip::init(bool search_in_AI_path) {
+    reinit();
+    return FGAIBase::init(search_in_AI_path);
+}
+
+void FGAIShip::reinit()
+{
     prev = 0; // the one behind you
     curr = 0; // the one ahead
     next = 0; // the next plus 1
@@ -134,7 +140,7 @@ bool FGAIShip::init(bool search_in_AI_path) {
     if (fp)
         _fp_init = initFlightPlan();
 
-    return FGAIBase::init(search_in_AI_path);
+    FGAIBase::reinit();
 }
 
 void FGAIShip::bind() {

src/AIModel/AIShip.hxx

@@ -41,8 +41,9 @@ public:
     virtual void bind();
     virtual void unbind();
     virtual void update(double dt);
+    virtual void reinit();
+
     void setFlightPlan(FGAIFlightPlan* f);
-//    void setName(const string&);
     void setRudder(float r);
     void setRoll(double rl);
     void ProcessFlightPlan( double dt);
@@ -90,14 +91,9 @@ public:
 
 protected:
 
-//    string _name; // The name of this ship.
-
 private:
 
 
-
-    virtual void reinit() { init(); }
-
     void setRepeat(bool r);
     void setRestart(bool r);
     void setMissed(bool m);

src/AIModel/AIWingman.cxx

@@ -203,7 +203,11 @@ void FGAIWingman::unbind() {
 bool FGAIWingman::init(bool search_in_AI_path) {
     if (!FGAIBallistic::init(search_in_AI_path))
         return false;
+    reinit();
+    return true;
+}
 
+void FGAIWingman::reinit() {
     invisible = false;
 
     _tgt_x_offset = _x_offset;
@@ -223,7 +227,8 @@ bool FGAIWingman::init(bool search_in_AI_path) {
 
     props->setStringValue("submodels/path", _path.c_str());
     user_WoW_node      = fgGetNode("gear/gear[1]/wow", true);
-    return true;
+
+    FGAIBallistic::reinit();
 }
 
 void FGAIWingman::update(double dt) {

src/AIModel/AIWingman.hxx

@@ -35,17 +35,16 @@ public:
     virtual ~FGAIWingman();
 
     virtual void readFromScenario(SGPropertyNode* scFileNode);
-    virtual void bind();
-    virtual void unbind();
-    virtual const char* getTypeString(void) const { return "wingman"; }
 
     bool init(bool search_in_AI_path=false);
-
-private:
-
-    virtual void reinit() { init(); }
+    virtual void bind();
+    virtual void unbind();
+    virtual void reinit();
     virtual void update (double dt);
 
+    virtual const char* getTypeString(void) const { return "wingman"; }
+
+private:
     void formateToAC(double dt);
     void Break(double dt);
     void Join(double dt);