From Wang Rui, "I've encountered a strange problem that osgviewerMFC doesn't work well

with the StatsHandler. When the 's' key is pressed, the rendering
window will be halted. I tried solving the problem by commenting a
line in CMFC_OSG_MDIView::OnKeyDown() and it seems to work now.

Another improvement here is to use a thread class derived from
OpenThreads to replace the old _beginthread(). It helps a lot in
keeping a high frame rate when you open more than one MDI child
windows. And the application using OpenThreads in my opinion will be
more compatible and portable."

examples/osgviewerMFC/MFC_OSG.cpp

@@ -52,6 +52,7 @@ void cOSG::InitSceneGraph(void)
 
     // Load the Model from the model name
     mModel = osgDB::readNodeFile(m_ModelName);
+    if (!mModel) return;
 
     // Optimize the model
     osgUtil::Optimizer optimizer;
@@ -141,7 +142,7 @@ void cOSG::PostFrameUpdate()
     // Due any postframe updates in this routine
 }
 
-void cOSG::Render(void* ptr)
+/*void cOSG::Render(void* ptr)
 {
     cOSG* osg = (cOSG*)ptr;
 
@@ -166,4 +167,33 @@ void cOSG::Render(void* ptr)
     AfxMessageBox("Exit Rendering Thread");
 
     _endthread();
+}*/
+
+CRenderingThread::CRenderingThread( cOSG* ptr )
+:   OpenThreads::Thread(), _ptr(ptr), _done(false)
+{
+}
+
+CRenderingThread::~CRenderingThread()
+{
+    _done = true;
+    while( isRunning() )
+        OpenThreads::Thread::YieldCurrentThread();
+}
+
+void CRenderingThread::run()
+{
+    if ( !_ptr )
+    {
+        _done = true;
+        return;
+    }
+
+    osgViewer::Viewer* viewer = _ptr->getViewer();
+    do
+    {
+        _ptr->PreFrameUpdate();
+        viewer->frame();
+        _ptr->PostFrameUpdate();
+    } while ( !testCancel() && !viewer->done() && !_done );
 }

examples/osgviewerMFC/MFC_OSG.h

@@ -27,7 +27,7 @@ public:
     void PostFrameUpdate(void);
     void Done(bool value) { mDone = value; }
     bool Done(void) { return mDone; }
-    static void Render(void* ptr);
+    //static void Render(void* ptr);
 
     osgViewer::Viewer* getViewer() { return mViewer; }
 
@@ -41,3 +41,16 @@ private:
     osg::ref_ptr<osgGA::TrackballManipulator> trackball;
     osg::ref_ptr<osgGA::KeySwitchMatrixManipulator> keyswitchManipulator;
 };
+
+class CRenderingThread : public OpenThreads::Thread
+{
+public:
+    CRenderingThread( cOSG* ptr );
+    virtual ~CRenderingThread();
+
+    virtual void run();
+
+protected:
+    cOSG* _ptr;
+    bool _done;
+};

examples/osgviewerMFC/MFC_OSG_MDIView.cpp

@@ -75,9 +75,10 @@ int CMFC_OSG_MDIView::OnCreate(LPCREATESTRUCT lpCreateStruct)
 
 void CMFC_OSG_MDIView::OnDestroy()
 {
+    delete mThreadHandle;
     if(mOSG != 0) delete mOSG;
 
-    WaitForSingleObject(mThreadHandle, 1000);
+    //WaitForSingleObject(mThreadHandle, 1000);
 
     CView::OnDestroy();
 }
@@ -93,13 +94,15 @@ void CMFC_OSG_MDIView::OnInitialUpdate()
     mOSG->InitOSG(csFileName.GetString());
 
     // Start the thread to do OSG Rendering
-    mThreadHandle = (HANDLE)_beginthread(&cOSG::Render, 0, mOSG); 
+    //mThreadHandle = (HANDLE)_beginthread(&cOSG::Render, 0, mOSG); 
+    mThreadHandle = new CRenderingThread(mOSG);
+    mThreadHandle->start();
 }
 
 void CMFC_OSG_MDIView::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)
 {
     // Pass Key Presses into OSG
-    mOSG->getViewer()->getEventQueue()->keyPress(nChar);
+    //mOSG->getViewer()->getEventQueue()->keyPress(nChar);
 
     // Close Window on Escape Key
     if(nChar == VK_ESCAPE)

examples/osgviewerMFC/MFC_OSG_MDIView.h

@@ -34,7 +34,8 @@ public:
 
 protected:
     cOSG* mOSG;
-    HANDLE mThreadHandle;
+    //HANDLE mThreadHandle;
+    CRenderingThread* mThreadHandle;
 
 // Generated message map functions
 protected: