Refactor ownership of terrain views

apps/openmw/mwworld/cellpreloader.cpp

@@ -207,7 +207,6 @@ namespace MWWorld
             mTerrainPreloadItem = NULL;
         }
 
-        mTerrain->removeView(mTerrainView);
         mTerrainView = NULL;
 
         for (PreloadMap::iterator it = mPreloadCells.begin(); it != mPreloadCells.end();++it)

apps/openmw/mwworld/cellpreloader.hpp

@@ -103,7 +103,7 @@ namespace MWWorld
         // Cells that are currently being preloaded, or have already finished preloading
         PreloadMap mPreloadCells;
 
-        Terrain::View* mTerrainView;
+        osg::ref_ptr<Terrain::View> mTerrainView;
         std::vector<osg::Vec3f> mTerrainPreloadPositions;
         osg::ref_ptr<SceneUtil::WorkItem> mTerrainPreloadItem;
     };

components/terrain/quadtreeworld.cpp

@@ -386,14 +386,7 @@ void QuadTreeWorld::enable(bool enabled)
 
 View* QuadTreeWorld::createView()
 {
-    ViewData* vd = mViewDataMap->createOrReuseView();
+    return new ViewData;
-    vd->setPersistent(true);
-    return vd;
-}
-
-void QuadTreeWorld::removeView(View *view)
-{
-    mViewDataMap->removeView(static_cast<ViewData*>(view));
 }
 
 void QuadTreeWorld::preload(View *view, const osg::Vec3f &eyePoint)

components/terrain/quadtreeworld.hpp

@@ -29,7 +29,6 @@ namespace Terrain
         virtual void enable(bool enabled);
 
         View* createView();
-        void removeView(View* view);
         void preload(View* view, const osg::Vec3f& eyePoint);
 
         void reportStats(unsigned int frameNumber, osg::Stats* stats);

components/terrain/viewdata.cpp

@@ -7,7 +7,6 @@ ViewData::ViewData()
     : mNumEntries(0)
     , mFrameLastUsed(0)
     , mChanged(false)
-    , mPersistent(false)
 {
 
 }
@@ -126,20 +125,12 @@ ViewData *ViewDataMap::createOrReuseView()
     }
 }
 
-void ViewDataMap::removeView(ViewData* vd)
-{
-    vd->setPersistent(false);
-    vd->clear();
-    mUnusedViews.push_back(vd);
-}
-
 void ViewDataMap::clearUnusedViews(unsigned int frame)
 {
     for (Map::iterator it = mViews.begin(); it != mViews.end(); )
     {
         ViewData* vd = it->second;
-        if (!vd->getPersistent() &&
+        if ((!vd->getViewer() // if no ref was held, always need to clear to avoid holding a dangling ref.
-                (!vd->getViewer() // if no ref was held, always need to clear to avoid holding a dangling ref.
                 || vd->getFrameLastUsed() + 2 < frame))
         {
             vd->setViewer(NULL);

components/terrain/viewdata.hpp

@@ -44,9 +44,6 @@ namespace Terrain
 
         Entry& getEntry(unsigned int i);
 
-        bool getPersistent() const { return mPersistent; }
-        void setPersistent(bool persistent) { mPersistent = persistent; }
-
         osg::Object* getViewer() const { return mViewer.get(); }
         void setViewer(osg::Object* viewer) { mViewer = viewer; }
 
@@ -60,7 +57,6 @@ namespace Terrain
         unsigned int mNumEntries;
         unsigned int mFrameLastUsed;
         bool mChanged;
-        bool mPersistent;
         osg::ref_ptr<osg::Object> mViewer;
     };
 
@@ -70,7 +66,6 @@ namespace Terrain
         ViewData* getViewData(osg::Object* viewer, bool ref);
 
         ViewData* createOrReuseView();
-        void removeView(ViewData* view);
 
         void clearUnusedViews(unsigned int frame);
 

components/terrain/world.hpp

@@ -2,6 +2,7 @@
 #define COMPONENTS_TERRAIN_WORLD_H
 
 #include <osg/ref_ptr>
+#include <osg/Referenced>
 #include <osg/Vec3f>
 
 #include <memory>
@@ -32,7 +33,7 @@ namespace Terrain
      * @brief A View is a collection of rendering objects that are visible from a given camera/intersection.
      * The base View class is part of the interface for usage in conjunction with preload feature.
      */
-    class View
+    class View : public osg::Referenced
     {
     public:
         virtual ~View() {}
@@ -79,14 +80,10 @@ namespace Terrain
 
         virtual void enable(bool enabled) {}
 
-        /// Create a View to use with preload feature. If a View is returned, it will remain valid until the user calls 'removeView' or the World is destroyed.
+        /// Create a View to use with preload feature. The caller is responsible for deleting the view.
-        /// @note Not thread safe.
+        /// @note Thread safe.
         virtual View* createView() { return NULL; }
 
-        /// Remove a View that was previously created with 'createView'.
-        /// @note Not thread safe.
-        virtual void removeView(View* view) {}
-
         /// @note Thread safe, as long as you do not attempt to load into the same view from multiple threads.
         virtual void preload(View* view, const osg::Vec3f& eyePoint) {}