Merge pull request #957 from dan-t/camera_callback_fixes

Fix camera callbacks of OcclusionQueryNode

include/osg/Callback

@@ -121,8 +121,33 @@ class OSG_EXPORT Callback : public virtual Object {
             }
         }
 
-    protected:
+        /** Convenience method to find a nested callback by type. */
+        template <typename T>
+        static T* findNestedCallback(osg::Callback* callback)
+        {
+            if (!callback)
+                return nullptr;
+
+            if (T* cb = dynamic_cast<T*>(callback))
+                return cb;
 
+            return findNestedCallback<T>(callback->getNestedCallback());
+        }
+
+        /** Convenience method to find a nested callback by type. */
+        template <typename T>
+        static const T* findNestedCallback(const osg::Callback* callback)
+        {
+            if (!callback)
+                return nullptr;
+
+            if (const T* cb = dynamic_cast<const T*>(callback))
+                return cb;
+
+            return findNestedCallback<T>(callback->getNestedCallback());
+        }
+
+    protected:
         virtual ~Callback() {}
         ref_ptr<Callback> _nestedCallback;
 };

include/osg/Camera

@@ -642,6 +642,14 @@ class OSG_EXPORT Camera : public Transform, public CullSettings
         /** Get the const initial draw callback.*/
         const DrawCallback* getInitialDrawCallback() const { return _initialDrawCallback.get(); }
 
+        /** Convenience method to find a nested initial draw callback by type. */
+        template <typename T>
+        T* findInitialDrawCallback() { return osg::Callback::findNestedCallback<T>(_initialDrawCallback.get()); }
+
+        /** Convenience method to find a nested initial draw callback by type. */
+        template <typename T>
+        const T* findInitialDrawCallback() const { return osg::Callback::findNestedCallback<T>(_initialDrawCallback.get()); }
+
         /** Convenience method that sets DrawCallback Initial callback of the node if it doesn't exist, or nest it into the existing one. */
         inline void addInitialDrawCallback(DrawCallback* nc)
         {
@@ -680,6 +688,14 @@ class OSG_EXPORT Camera : public Transform, public CullSettings
         /** Get the const pre draw callback.*/
         const DrawCallback* getPreDrawCallback() const { return _preDrawCallback.get(); }
 
+        /** Convenience method to find a nested pre draw callback by type. */
+        template <typename T>
+        T* findPreDrawCallback() { return osg::Callback::findNestedCallback<T>(_preDrawCallback.get()); }
+
+        /** Convenience method to find a nested pre draw callback by type. */
+        template <typename T>
+        const T* findPreDrawCallback() const { return osg::Callback::findNestedCallback<T>(_preDrawCallback.get()); }
+
         /** Convenience method that sets DrawCallback Initial callback of the node if it doesn't exist, or nest it into the existing one. */
         inline void addPreDrawCallback(DrawCallback* nc)
         {
@@ -718,6 +734,14 @@ class OSG_EXPORT Camera : public Transform, public CullSettings
         /** Get the const post draw callback.*/
         const DrawCallback* getPostDrawCallback() const { return _postDrawCallback.get(); }
 
+        /** Convenience method to find a nested post draw callback by type. */
+        template <typename T>
+        T* findPostDrawCallback() { return osg::Callback::findNestedCallback<T>(_postDrawCallback.get()); }
+
+        /** Convenience method to find a nested post draw callback by type. */
+        template <typename T>
+        const T* findPostDrawCallback() const { return osg::Callback::findNestedCallback<T>(_postDrawCallback.get()); }
+
         /** Convenience method that sets DrawCallback Initial callback of the node if it doesn't exist, or nest it into the existing one. */
         inline void addPostDrawCallback(DrawCallback* nc)
         {
@@ -756,6 +780,14 @@ class OSG_EXPORT Camera : public Transform, public CullSettings
         /** Get the const final draw callback.*/
         const DrawCallback* getFinalDrawCallback() const { return _finalDrawCallback.get(); }
 
+        /** Convenience method to find a nested final draw callback by type. */
+        template <typename T>
+        T* findFinalDrawCallback() { return osg::Callback::findNestedCallback<T>(_finalDrawCallback.get()); }
+
+        /** Convenience method to find a nested final draw callback by type. */
+        template <typename T>
+        const T* findFinalDrawCallback() const { return osg::Callback::findNestedCallback<T>(_finalDrawCallback.get()); }
+
         /** Convenience method that sets DrawCallback Initial callback of the node if it doesn't exist, or nest it into the existing one. */
         inline void addFinalDrawCallback(DrawCallback* nc)
         {

src/osg/OcclusionQueryNode.cpp

@@ -320,15 +320,20 @@ QueryGeometry::drawImplementation( osg::RenderInfo& renderInfo ) const
 
     osg::Camera* cam = renderInfo.getCurrentCamera();
 
-    // Add callbacks if necessary.
-    if (!cam->getPostDrawCallback())
+    RetrieveQueriesCallback* rqcb = cam->findPostDrawCallback<RetrieveQueriesCallback>();
+    if (!rqcb)
     {
-        RetrieveQueriesCallback* rqcb = new RetrieveQueriesCallback( ext );
-        cam->setPostDrawCallback( rqcb );
+        rqcb = new RetrieveQueriesCallback( ext );
+        cam->addPostDrawCallback( rqcb );
+
+        ClearQueriesCallback* cqcb = cam->findPreDrawCallback<ClearQueriesCallback>();
+        if (!cqcb)
+        {
+            cqcb = new ClearQueriesCallback;
+            cam->addPreDrawCallback( cqcb );
+        }
 
-        ClearQueriesCallback* cqcb = new ClearQueriesCallback;
         cqcb->_rqcb = rqcb;
-        cam->setPreDrawCallback( cqcb );
     }
 
     // Get TestResult from Camera map
@@ -343,7 +348,6 @@ QueryGeometry::drawImplementation( osg::RenderInfo& renderInfo ) const
         }
     }
 
-
     // Issue query
     if (!tr->_init)
     {
@@ -358,9 +362,6 @@ QueryGeometry::drawImplementation( osg::RenderInfo& renderInfo ) const
         return;
     }
 
-    // Add TestResult to RQCB.
-    RetrieveQueriesCallback* rqcb = dynamic_cast<
-        RetrieveQueriesCallback* >( cam->getPostDrawCallback() );
     if (!rqcb)
     {
         OSG_FATAL << "osgOQ: QG: Invalid RQCB." << std::endl;