Added initial cut at support for osgVolume in .ive format.

src/osgPlugins/ive/Volume.cpp

@@ -0,0 +1,47 @@
+/* -*-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.
+*/
+
+#include "Exception.h"
+#include "Volume.h"
+#include "Group.h"
+
+using namespace ive;
+
+void Volume::write(DataOutputStream* out)
+{
+    // Write Volume's identification.
+    out->writeInt(IVEVOLUME);
+    // If the osg class is inherited by any other class we should also write this to file.
+    osg::Group*  group = dynamic_cast<osg::Group*>(this);
+    if(group)
+        ((ive::Group*)(group))->write(out);
+    else
+        throw Exception("Volume::write(): Could not cast this osgVolume::Volume to an osg::Group.");
+}
+
+void Volume::read(DataInputStream* in)
+{
+    // Peek on Volume's identification.
+    int id = in->peekInt();
+    if (id != IVEVOLUME) throw Exception("Volume::read(): Expected Volume identification.");
+
+    // Read Volume's identification.
+    id = in->readInt();
+    // If the osg class is inherited by any other class we should also read this from file.
+    osg::Group*  group = dynamic_cast<osg::Group*>(this);
+    if(group)
+        ((ive::Group*)(group))->read(in);
+    else
+        throw Exception("Volume::read(): Could not cast this osgVolume::Volume to an osg::Group.");
+
+}