Added automatically removal from the OjbectCache when a object or it's subgraph contain Texture that no longer have an osg::Image.

src/osgDB/ObjectCache.cpp

@@ -11,6 +11,7 @@
  * OpenSceneGraph Public License for more details.
 */
 
+#include <osg/Texture>
 #include <osgDB/ObjectCache>
 #include <osgDB/Options>
 
@@ -188,15 +189,95 @@ void ObjectCache::clear()
     _objectCache.clear();
 }
 
+namespace ObjectCacheUtils
+{
+
+struct ContainsUnreffedTextures : public osg::NodeVisitor
+{
+    ContainsUnreffedTextures() :
+        osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
+        foundUnreffedTexture(false)
+    {}
+
+    bool foundUnreffedTexture;
+
+    bool check(const osg::Texture* texture)
+    {
+        if (!texture) return false;
+
+        unsigned int numImages = 0;
+        for(unsigned int i=0; i<texture->getNumImages(); ++i)
+        {
+            if (texture->getImage(i)) ++numImages;
+        }
+
+        return numImages==0;
+    }
+
+    bool check(const osg::StateSet* stateset)
+    {
+        for(unsigned int i=0; i<stateset->getNumTextureAttributeLists(); ++i)
+        {
+            const osg::StateAttribute* sa = stateset->getTextureAttribute(i, osg::StateAttribute::TEXTURE);
+            if (sa && check(sa->asTexture())) return true;
+        }
+        return false;
+    }
+
+    bool check(osg::Object* object)
+    {
+        if (object->asStateAttribute()) return check(dynamic_cast<const osg::Texture*>(object));
+        if (object->asStateSet()) return check(object->asStateSet());
+        if (!object->asNode()) return false;
+
+        foundUnreffedTexture = false;
+
+        object->asNode()->accept(*this);
+
+        return foundUnreffedTexture;
+    }
+
+    void apply(osg::Node& node)
+    {
+        if (node.getStateSet())
+        {
+            if (check(node.getStateSet()))
+            {
+                foundUnreffedTexture = true;
+                return;
+            }
+        }
+
+        traverse(node);
+    }
+};
+
+} // ObjectCacheUtils
+
 void ObjectCache::releaseGLObjects(osg::State* state)
 {
     OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_objectCacheMutex);
 
+    ObjectCacheUtils::ContainsUnreffedTextures cut;
+
     for(ObjectCacheMap::iterator itr = _objectCache.begin();
         itr != _objectCache.end();
-        ++itr)
+        )
     {
+        ObjectCacheMap::iterator curr_itr = itr;
+
+        // get object and advance iterator to next item
         osg::Object* object = itr->second.first.get();
+
+        bool needToRemoveEntry = cut.check(itr->second.first.get());
+
         object->releaseGLObjects(state);
+
+        ++itr;
+
+        if (needToRemoveEntry)
+        {
+            _objectCache.erase(curr_itr);
+        }
     }
 }