+ void add_track(Track3D &);
+ void remove_track(Track3D &);
+ const std::list<Track3D *> &get_tracks() const { return tracks; }
+ Track3D &get_track(const Track &) const;
+ Track3D *pick_track(float, float, float) const;
+
+ Msp::GL::Scene &get_scene() { return scene; }
+ Msp::GL::Scene &get_endpoint_scene() { return ep_scene; }
+
+private:
+ void track_added(Track &);
+ void track_removed(Track &);