Reorginized the TerrainTile/TerrainTechnique dirty mechanism so that TerrainTile

now holds the dirty flag and enables/disables event traversal in response dirty
being set/unset.  This allows terrain to be automatically updated in response
to Terrain scale and sample ratio changes.

include/osgTerrain/GeometryTechnique

@@ -57,10 +57,6 @@ class OSGTERRAIN_EXPORT GeometryTechnique : public TerrainTechnique
 
         virtual void cleanSceneGraph();
 
-        virtual void dirty();
-        
-        
-        
         void setFilterBias(float filterBias);
         float getFilterBias() const { return _filterBias; }
         

include/osgTerrain/TerrainTechnique

@@ -51,20 +51,15 @@ class OSGTERRAIN_EXPORT TerrainTechnique : public osg::Object
         /** Traverse the terrain subgraph.*/
         virtual void traverse(osg::NodeVisitor& nv);
 
-        /** Dirty so that cached data structures will be updated on next use.*/
-        virtual void dirty();
-
-        /** Return true if cached data structures need updating.*/
-        virtual bool isDirty() const { return _dirty; }
-
     protected:
+    
+        void setDirty(bool dirty);
 
         virtual ~TerrainTechnique();
         
         friend class osgTerrain::TerrainTile;
 
         TerrainTile*    _terrainTile;
-        bool            _dirty;
 
 };
 

include/osgTerrain/TerrainTile

@@ -160,6 +160,11 @@ class OSGTERRAIN_EXPORT TerrainTile : public osg::Group
         /** Get whether the TeatBoundariesToValidDataAsDefaultValue hint.*/
         bool getTreatBoundariesToValidDataAsDefaultValue() const { return _treatBoundariesToValidDataAsDefaultValue; }
 
+        /** Set the dirty flag on/off.*/
+        void setDirty(bool dirty);
+
+        /** return true if the tile is dirty and needs to be updated,*/
+        bool getDirty() const { return _dirty; }
 
         /** Compute the bounding volume of the terrain by computing the union of the bounding volumes of all layers.*/
         virtual osg::BoundingSphere computeBound() const;
@@ -168,12 +173,14 @@ class OSGTERRAIN_EXPORT TerrainTile : public osg::Group
 
         virtual ~TerrainTile();
 
+
         typedef std::vector< osg::ref_ptr<Layer> > Layers;
 
         friend class Terrain;
 
         Terrain*                            _terrain;
-
+        
+        bool                                _dirty;
         bool                                _hasBeenTraversal;
         
         TileID                              _tileID;