Create initial class placeholders for main volume rendering classes

include/osgVolume/Volume

@@ -0,0 +1,68 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2008 Robert Osfield 
+ *
+ * This library is open source and may be redistributed and/or modified under  
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ * OpenSceneGraph Public License for more details.
+*/
+
+#ifndef OSGVOLUME
+#define OSGVOLUME 1
+
+#include <osg/Group>
+#include <osg/CoordinateSystemNode>
+
+#include <osgVolume/Brick>
+
+namespace osgVolume {
+
+/** Volume provides a framework for loosely coupling 3d image Brick's with volume algorithms.
+  * This allows VolumeTechnique's to be plugged in at runtime.*/
+class OSGVOLUME_EXPORT Volume : public osg::Group
+{
+    public:
+
+        Volume();
+        
+        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
+        Volume(const Volume&,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
+
+        META_Node(osgVolume, Volume);
+
+        virtual void traverse(osg::NodeVisitor& nv);
+        
+        /** Get the Brick for a given BrickID.*/
+        Brick* getBrick(const BrickID& brickID);
+
+        /** Get the const Brick for a given BrickID.*/
+        const Brick* getBrick(const BrickID& brickID) const;
+
+    protected:
+
+        virtual ~Volume();
+        
+        friend class Brick;
+        
+        void dirtyRegisteredBricks();
+
+        void registerBrick(Brick* tile);
+        void unregisterBrick(Brick* tile);
+
+        typedef std::map< BrickID, Brick* >    BrickMap;
+        typedef std::set< Brick* >      BrickSet;
+
+        mutable OpenThreads::Mutex          _mutex;
+        BrickSet                            _brickSet;
+        BrickMap                            _brickMap;
+
+       
+};
+
+}
+
+#endif