Added support for cullable state, that uses a polytope to define the extents

of objects that will be influenced by it.

src/osgSim/OverlayNode.cpp

@@ -13,6 +13,7 @@
 
 #include <osg/Texture2D>
 #include <osg/CoordinateSystemNode>
+#include <osg/io_utils>
 
 #include <osgUtil/CullVisitor>
 #include <osgSim/OverlayNode>
@@ -116,10 +117,6 @@ void OverlayNode::traverse(osg::NodeVisitor& nv)
 
         if (bs.valid())
         {
-            // update the bounding volume for later testing
-            // whether the overlay can be seen or not.
-            _overlaySubgraphBound = bs;
-
             // see if we are within a coordinate system node.
             osg::CoordinateSystemNode* csn = 0;
             osg::NodePath& nodePath = nv.getNodePath();
@@ -171,8 +168,10 @@ void OverlayNode::traverse(osg::NodeVisitor& nv)
 
             // compute the matrix which takes a vertex from local coords into tex coords
             // will use this later to specify osg::TexGen..
-            osg::Matrix MVPT = _camera->getViewMatrix() * 
-                               _camera->getProjectionMatrix() *
+            osg::Matrix MVP = _camera->getViewMatrix() * 
+                              _camera->getProjectionMatrix();
+
+            osg::Matrix MVPT = MVP *
                                osg::Matrix::translate(1.0,1.0,1.0) *
                                osg::Matrix::scale(0.5,0.5,0.5);
 
@@ -180,6 +179,11 @@ void OverlayNode::traverse(osg::NodeVisitor& nv)
             _texgenNode->getTexGen()->setPlanesFromMatrix(MVPT);
 
 
+            _textureFrustum.setToUnitFrustum(false,false);
+//            const osg::Matrix modelView = (cv->getModelViewMatrix());
+//            _textureFrustum.transformProvidingInverse(osg::Matrix::inverse(modelView)*MVP);
+            _textureFrustum.transformProvidingInverse(MVP);
+
             _camera->accept(*cv);
 
             _textureObjectValidList[contextID] = 1;
@@ -202,14 +206,28 @@ void OverlayNode::traverse(osg::NodeVisitor& nv)
     else
 #endif
     {
+
         _texgenNode->accept(*cv);
+        
+        osg::CullingSet& pcs = cv->getProjectionCullingStack().back();
+        osg::CullingSet& ccs = cv->getCurrentCullingSet();
+
+        const osg::Matrix modelView = (cv->getModelViewMatrix());
+        osg::Polytope viewTextureFrustum;
+        viewTextureFrustum.setAndTransformProvidingInverse(_textureFrustum, osg::Matrix::inverse(modelView));
+
+        pcs.addStateFrustum(_mainSubgraphStateSet.get(), viewTextureFrustum);
+        ccs.addStateFrustum(_mainSubgraphStateSet.get(), _textureFrustum);
 
         // push the stateset.
-        cv->pushStateSet(_mainSubgraphStateSet.get());
+        // cv->pushStateSet(_mainSubgraphStateSet.get());
 
         Group::traverse(nv);
 
-        cv->popStateSet();
+        // cv->popStateSet();
+        
+        ccs.getStateFrustumList().pop_back();
+        pcs.getStateFrustumList().pop_back();
     }
 }
 

src/osgUtil/CullVisitor.cpp

@@ -25,6 +25,7 @@
 #include <osg/LineSegment>
 #include <osg/TriangleFunctor>
 #include <osg/Geometry>
+#include <osg/io_utils>
 
 #include <osgUtil/CullVisitor>
 
@@ -745,14 +746,40 @@ void CullVisitor::apply(Geode& node)
             if (!updateCalculatedNearFar(matrix,*drawable,false)) continue;
         }
 
+        // need to track how push/pops there are, so we can unravel the stack correctly.
+        unsigned int numPopStateSetRequired = 0;
+
         // push the geoset's state on the geostate stack.    
         StateSet* stateset = drawable->getStateSet();
-        if (stateset) pushStateSet(stateset);
+        if (stateset)
+        {
+            ++numPopStateSetRequired;
+            pushStateSet(stateset);
+        }
+
+        CullingSet& cs = getCurrentCullingSet();
+        if (!cs.getStateFrustumList().empty())
+        {
+            osg::CullingSet::StateFrustumList& sfl = cs.getStateFrustumList();
+            for(osg::CullingSet::StateFrustumList::iterator itr = sfl.begin();
+                itr != sfl.end();
+                ++itr)
+            {
+                if (itr->second.contains(bb))
+                {
+                    ++numPopStateSetRequired;
+                    pushStateSet(itr->first.get());
+                }
+            }
+        }
 
         if (bb.valid()) addDrawableAndDepth(drawable,&matrix,distance(bb.center(),matrix));
 	else addDrawableAndDepth(drawable,&matrix,0.0f);
 
-        if (stateset) popStateSet();
+        for(unsigned int i=0;i< numPopStateSetRequired; ++i)
+        {
+            popStateSet();
+        }
 
     }