Inroduced simple PrintVisitor class for helping debug scene graph structures

include/osgUtil/PrintVisitor

@@ -0,0 +1,49 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2009 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 OSGUTIL_PRINTVISITOR
+#define OSGUTIL_PRINTVISITOR 1
+
+#include <osg/NodeVisitor>
+#include <osgUtil/Export>
+
+#include <ostream>
+
+namespace osgUtil {
+
+class OSGUTIL_EXPORT PrintVisitor : public osg::NodeVisitor
+{
+    public:
+
+        PrintVisitor(std::ostream& out, int indent=0, int step=2);
+
+        void apply(osg::Node& node);
+
+        std::ostream& output()
+        {
+            for(unsigned int i=0;i<_indent; ++i) _out<<" ";
+            return _out;
+        }
+
+        void enter() { _indent += _step; }
+        void leave() { _indent -= _step; }
+
+        std::ostream& _out;
+        unsigned int _indent;
+        unsigned int _step;
+};
+
+}
+
+#endif
+