Added osgPresentation::Cursor class to wrap up 3D cursor in the scene functionality

include/osgPresentation/Cursor

@@ -0,0 +1,65 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 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 OSGPRESENTATION_CURSOR
+#define OSGPRESENTATION_CURSOR 1
+
+#include <osg/AutoTransform>
+#include <osg/Camera>
+#include <osgPresentation/Export>
+
+namespace osgPresentation {
+
+class OSGPRESENTATION_EXPORT Cursor : public osg::Group
+{
+    public:
+
+        Cursor();
+
+        Cursor(const std::string& filename, float size);
+
+        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
+        Cursor(const Cursor& rhs,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
+
+        META_Node(osgPresentation, Cursor)
+
+        void setFilename(const std::string& filename) { _filename = filename; _cursorDirty=true; }
+        const std::string& getFilename() const { return _filename; }
+
+        void setSize(float size) { _size = size; _cursorDirty=true; }
+        float getSize() const { return _size; }
+
+        virtual void traverse(osg::NodeVisitor& nv);
+
+    protected:
+
+        virtual ~Cursor();
+
+        void initializeCursor();
+        void updatePosition();
+
+        std::string _filename;
+        float       _size;
+
+        bool _cursorDirty;
+
+        osg::ref_ptr<osg::AutoTransform> _transform;
+
+        osg::Vec2                       _cursorXY;
+        osg::observer_ptr<osg::Camera>  _camera;
+
+};
+
+}
+
+#endif