Added support for AbortRendering flag pointer in osg::State which is used

by osgUtil::RenderLeaf to test if any abort state has been set, if so it
doesn't do any further drawing.

The osgProducer::Viewer has been set up to set the osg::State's it manages
with their AbortRendering flag pointers set to the osgProducer::Viewer::_done
memeber varaible.  Now when escape is pressed the rendering is aborted early.

include/osg/State

@@ -565,6 +565,14 @@ class SG_EXPORT State : public Referenced
         typedef std::vector<StateAttribute::GLModeValue>                        ValueVec;
         
         
+        /** Set flag for early termination of the draw traversal.*/
+        void setAbortRenderingPtr(bool* abortPtr) { _abortRenderingPtr = abortPtr; }
+
+        /** Get flag for early termination of the draw traversal, 
+          * if true steps should be taken to complete rendering early.*/
+        bool getAbortRendering() const { return _abortRenderingPtr!=0?(*_abortRenderingPtr):false; }
+
+        
         void setReportGLErrors(bool flag) { _reportGLErrors = flag; }
         bool getReportGLErrors() const { return _reportGLErrors; }
 
@@ -572,6 +580,7 @@ class SG_EXPORT State : public Referenced
         bool checkGLErrors(StateAttribute::GLMode mode) const;
         bool checkGLErrors(const StateAttribute* attribute) const;
 
+
     protected:
 
         virtual ~State();
@@ -585,7 +594,7 @@ class SG_EXPORT State : public Referenced
         
         ref_ptr<DisplaySettings>    _displaySettings;
         
-
+        bool*                       _abortRenderingPtr;
         bool                        _reportGLErrors;
 
         struct ModeStack

src/osg/State.cpp

@@ -23,7 +23,8 @@ State::State()
     _identity = new osg::RefMatrix(); // default RefMatrix constructs to identity.
     _projection = _identity;
     _modelView = _identity;
-    
+
+    _abortRenderingPtr = false;    
     _reportGLErrors = true;
 
     _currentActiveTextureUnit=0;

src/osgProducer/KeyboardMouseCallback.cpp

@@ -26,6 +26,11 @@ void KeyboardMouseCallback::keyPress( Producer::KeySymbol key )
 #endif
     }
     
+    if (_done)
+    {
+        // need to contact the viewer so pass on the abort..
+    }
+    
     osg::ref_ptr<EventAdapter> event = new EventAdapter;
     event->adaptKeyPress(getTime(),key);
     

src/osgProducer/Viewer.cpp

@@ -187,6 +187,12 @@ void Viewer::realize( ThreadingModel thread_model)
 
     OsgCameraGroup::realize( thread_model );
     
+    // set up osg::State objects with a the _done prt to allow early termination of 
+    // draw traversal.
+    for(SceneHandlerList::iterator p=_shvec.begin(); p!=_shvec.end(); p++ )
+    {
+        (*p)->getState()->setAbortRenderingPtr(&_done);
+    }
     
 }
 

src/osgUtil/RenderLeaf.cpp

@@ -18,6 +18,12 @@ using namespace osgUtil;
 
 void RenderLeaf::render(State& state,RenderLeaf* previous)
 {
+    // don't draw this leaf if the abort rendering flag has been set.
+    if (state.getAbortRendering())
+    {
+        //cout << "early abort"<<endl;
+        return;
+    }
 
     if (previous)
     {