Address warnings found via Clang - especially related to destructor visibility with ref_ptrs of various kinds.

simgear/scene/material/EffectBuilder.cxx

@@ -102,4 +102,14 @@ namespace effect
 {
 const char* colorFields[] = {"red", "green", "blue", "alpha"};
 }
+  
+PassAttributeBuilder::~PassAttributeBuilder()
+{
 }
+  
+} // of namespace simgear
+
+
+
+
+

simgear/scene/material/EffectBuilder.hxx

@@ -350,8 +350,11 @@ protected:
     struct PassAttrMapSingleton : public simgear::Singleton<PassAttrMapSingleton>
     {
         PassAttrMap passAttrMap;
+      
     };
 public:
+    virtual ~PassAttributeBuilder(); // anchor into the compilation unit.
+  
     virtual void buildAttribute(Effect* effect, Pass* pass,
                                 const SGPropertyNode* prop,
                                 const SGReaderWriterXMLOptions* options)

simgear/scene/tgdb/obj.cxx

@@ -583,7 +583,7 @@ SGLoadBTG(const std::string& path, SGMaterialLib *matlib, bool calc_lights, bool
 {
   SGBinObject tile;
   if (!tile.read_bin(path))
-    return false;
+    return NULL;
 
   SGVec3d center = tile.get_gbs_center();
   SGGeod geodPos = SGGeod::fromCart(center);
@@ -604,7 +604,7 @@ SGLoadBTG(const std::string& path, SGMaterialLib *matlib, bool calc_lights, bool
 
   SGTileGeometryBin tileGeometryBin;
   if (!tileGeometryBin.insertBinObj(tile, matlib))
-    return false;
+    return NULL;
 
   SGVec3f up(0, 0, 1);
   GroundLightManager* lightManager = GroundLightManager::instance();

simgear/scene/util/StateAttributeFactory.cxx

@@ -86,4 +86,10 @@ StateAttributeFactory::StateAttributeFactory()
     _depthWritesDisabled->setDataVariance(Object::STATIC);
 }
 
+// anchor the destructor into this file, to avoid ref_ptr warnings
+StateAttributeFactory::~StateAttributeFactory()
+{
+  
+}
+  
 }

simgear/scene/util/StateAttributeFactory.hxx

@@ -45,6 +45,8 @@ namespace simgear
 class StateAttributeFactory :
         public ReferencedSingleton<StateAttributeFactory> {
 public:
+    ~StateAttributeFactory();
+          
     // Alpha test > .01
     osg::AlphaFunc* getStandardAlphaFunc() { return _standardAlphaFunc.get(); }
     // alpha source, 1 - alpha destination

simgear/sound/sample_openal.hxx

@@ -82,7 +82,7 @@ public:
     /**
      * Destructor
      */
-    ~SGSoundSample ();
+    virtual ~SGSoundSample ();
 
     /**
      * Detect wheter this audio sample holds the information of a sound file.