Fix Drawable removal issues

apps/openmw/mwrender/animation.cpp

@@ -175,58 +175,71 @@ namespace
         return 0.0f;
     }
 
-
-    // Removes all drawables from a graph.
-    class RemoveDrawableVisitor : public osg::NodeVisitor
+    /// @brief Base class for visitors that remove nodes from a scene graph.
+    /// Subclasses need to fill the mToRemove vector.
+    /// To use, node->accept(removeVisitor); removeVisitor.remove();
+    class RemoveVisitor : public osg::NodeVisitor
     {
     public:
-        RemoveDrawableVisitor()
+        RemoveVisitor()
             : osg::NodeVisitor(TRAVERSE_ALL_CHILDREN)
         {
         }
 
-        virtual void apply(osg::Geode &node)
+        void remove()
         {
-            // Not safe to remove in apply(), since the visitor is still iterating the child list
-            osg::Group* parent = node.getParent(0);
-            // prune nodes that would be empty after the removal
-            if (parent->getNumChildren() == 1 && parent->getDataVariance() == osg::Object::STATIC)
-                mToRemove.push_back(parent);
-            else
-                mToRemove.push_back(&node);
-            traverse(node);
+            for (RemoveVec::iterator it = mToRemove.begin(); it != mToRemove.end(); ++it)
+                it->second->removeChild(it->first);
+        }
+
+    protected:
+        // <node to remove, parent node to remove it from>
+        typedef std::vector<std::pair<osg::Node*, osg::Group*> > RemoveVec;
+        std::vector<std::pair<osg::Node*, osg::Group*> > mToRemove;
+    };
+
+    // Removes all drawables from a graph.
+    class RemoveDrawableVisitor : public RemoveVisitor
+    {
+    public:
+        virtual void apply(osg::Geode &geode)
+        {
+            applyImpl(geode);
         }
 
 #if OSG_VERSION_GREATER_OR_EQUAL(3,3,3)
         virtual void apply(osg::Drawable& drw)
         {
-            mToRemove.push_back(&drw);
+            applyImpl(drw);
         }
 #endif
 
-        void remove()
+        void applyImpl(osg::Node& node)
         {
-            for (std::vector<osg::Node*>::iterator it = mToRemove.begin(); it != mToRemove.end(); ++it)
+            osg::NodePath::iterator parent = getNodePath().end()-2;
+            // We know that the parent is a Group because only Groups can have children.
+            osg::Group* parentGroup = static_cast<osg::Group*>(*parent);
+
+            // Try to prune nodes that would be empty after the removal
+            if (parent != getNodePath().begin())
+            {
+                // This could be extended to remove the parent's parent, and so on if they are empty as well.
+                // But for NIF files, there won't be a benefit since only TriShapes can be set to STATIC dataVariance.
+                osg::Group* parentParent = static_cast<osg::Group*>(*(parent - 1));
+                if (parentGroup->getNumChildren() == 1 && parentGroup->getDataVariance() == osg::Object::STATIC)
                 {
-                // FIXME: a Drawable might have more than one parent
-                osg::Node* node = *it;
-                if (node->getNumParents())
-                    node->getParent(0)->removeChild(node);
+                    mToRemove.push_back(std::make_pair(parentGroup, parentParent));
+                    return;
                 }
             }
 
-    private:
-        std::vector<osg::Node*> mToRemove;
+            mToRemove.push_back(std::make_pair(&node, parentGroup));
+        }
     };
 
-    class RemoveTriBipVisitor : public osg::NodeVisitor
+    class RemoveTriBipVisitor : public RemoveVisitor
     {
     public:
-        RemoveTriBipVisitor()
-            : osg::NodeVisitor(TRAVERSE_ALL_CHILDREN)
-        {
-        }
-
         virtual void apply(osg::Geode &node)
         {
             applyImpl(node);
@@ -244,24 +257,11 @@ namespace
             const std::string toFind = "tri bip";
             if (Misc::StringUtils::ciCompareLen(node.getName(), toFind, toFind.size()) == 0)
             {
+                osg::Group* parent = static_cast<osg::Group*>(*(getNodePath().end()-2));
                 // Not safe to remove in apply(), since the visitor is still iterating the child list
-                mToRemove.push_back(&node);
+                mToRemove.push_back(std::make_pair(&node, parent));
             }
         }
-
-        void remove()
-        {
-            for (std::vector<osg::Node*>::iterator it = mToRemove.begin(); it != mToRemove.end(); ++it)
-            {
-                // FIXME: a Drawable might have more than one parent
-                osg::Node* node = *it;
-                if (node->getNumParents())
-                    node->getParent(0)->removeChild(node);
-            }
-        }
-
-    private:
-        std::vector<osg::Node*> mToRemove;
     };
 
 }