Partial fix for reset when using --composite-viewer=1.

[Marked as 'Partial' because, for me, reset eventually runs out of memory with
both composite-viewer and non-composite-viewer.]

fgStartNewReset(): pass existing composite_viewer to FGRenderer constructor so
that it is used after reset instead of us creating a new instance. Also reuse
existing osgViewer::View.

In FGRenderer::init(), don't create new osgViewer::CompositeViewer if
this->composite_viewer is already set.

src/Main/fg_init.cxx

@@ -1288,7 +1288,13 @@ void fgStartNewReset()
     FGRenderer* render = globals->get_renderer();
     // needed or we crash in multi-threaded OSG mode
     render->getViewerBase()->stopThreading();
-    
+
+    osg::ref_ptr<osgViewer::CompositeViewer> composite_viewer = render->getCompositeViewer();
+    osg::ref_ptr<osgViewer::View> composite_viewer_view;
+    if (composite_viewer) {
+        composite_viewer_view = render->getView();
+    }
+        
     // order is important here since tile-manager shutdown needs to
     // access the scenery object
     subsystemManger->remove(FGScenery::staticSubsystemClassId());
@@ -1375,21 +1381,39 @@ void fgStartNewReset()
     fgInitAircraftPaths(true);
     fgInitAircraft(true);
     
-    render = new FGRenderer;
+    render = new FGRenderer(composite_viewer);
     render->setEventHandler(eventHandler);
     eventHandler->reset();
     globals->set_renderer(render);
     render->init();
-    render->setView(viewer.get());
+    
+    if (composite_viewer) {
+        render->setView(composite_viewer_view);
+    }
+    else {
+        render->setView(viewer.get());
+    }
 
     sgUserDataInit( globals->get_props() );
 
-    viewer->getDatabasePager()->setUpThreads(20, 1);
-    
-    // must do this before preinit for Rembrandthe
-    flightgear::CameraGroup::buildDefaultGroup(viewer.get());
-    render->preinit();
-    viewer->startThreading();
+    if (composite_viewer) {
+        composite_viewer_view->getDatabasePager()->setUpThreads(20, 1);
+        flightgear::CameraGroup::buildDefaultGroup(composite_viewer_view);
+        composite_viewer_view->setFrameStamp(composite_viewer->getFrameStamp());
+        composite_viewer_view->setDatabasePager(FGScenery::getPagerSingleton());
+        composite_viewer_view->getDatabasePager()->setUnrefImageDataAfterApplyPolicy(true, false);
+        osg::GraphicsContext::createNewContextID();
+        render->setView(composite_viewer_view);
+        render->preinit();
+        composite_viewer->startThreading();
+    }
+    else {
+        viewer->getDatabasePager()->setUpThreads(20, 1);
+        // must do this before preinit for Rembrandthe
+        flightgear::CameraGroup::buildDefaultGroup(viewer.get());
+        render->preinit();
+        viewer->startThreading();
+    }
     
     fgOSResetProperties();
 

src/Viewer/renderer.cxx

@@ -351,6 +351,17 @@ FGRenderer::FGRenderer() :
     _updateVisitor = new SGUpdateVisitor;
 }
 
+FGRenderer::FGRenderer(osg::ref_ptr<osgViewer::CompositeViewer> composite_viewer) :
+    composite_viewer(composite_viewer),
+    _sky(NULL),
+    MaximumTextureSize(0)
+{
+	_root = new osg::Group;
+	_root->setName("fakeRoot");
+    _updateVisitor = new SGUpdateVisitor;
+}
+
+
 FGRenderer::~FGRenderer()
 {
     SGPropertyChangeListenerVec::iterator i = _listeners.begin();
@@ -462,7 +473,12 @@ FGRenderer::init( void )
         }
         composite_viewer_enabled = 1;
         SG_LOG(SG_VIEW, SG_ALERT, "Creating osgViewer::CompositeViewer");
-        composite_viewer = new osgViewer::CompositeViewer;
+        if (composite_viewer) {
+            // reinit.
+        }
+        else {
+            composite_viewer = new osgViewer::CompositeViewer;
+        }
         
         // https://stackoverflow.com/questions/15207076/openscenegraph-and-multiple-viewers
         composite_viewer->setReleaseContextAtEndOfFrameHint(false);
@@ -1016,6 +1032,11 @@ osgViewer::ViewerBase* FGRenderer::getViewerBase()
     }
 }
 
+osg::ref_ptr<osgViewer::CompositeViewer> FGRenderer::getCompositeViewer()
+{
+    return composite_viewer;
+}
+
 osgViewer::View* FGRenderer::getView()
 {
     /* Would like to assert that FGRenderer::init() has always been called

src/Viewer/renderer.hxx

@@ -50,6 +50,7 @@ class FGRenderer {
 public:
 
     FGRenderer();
+    FGRenderer(osg::ref_ptr<osgViewer::CompositeViewer> composite_viewer);
     ~FGRenderer();
 
     void preinit();
@@ -67,6 +68,9 @@ public:
     
     /* Returns either composite_viewer or viewer. */
     osgViewer::ViewerBase* getViewerBase();
+    
+    /** For handling reset. */
+    osg::ref_ptr<osgViewer::CompositeViewer> getCompositeViewer();
 
     /** Get and set the OSG Viewer object, if any.
      */