+void gis_viewer_setup(GisViewer *viewer, GisPlugins *plugins, GisPrefs *prefs);
+
+void gis_viewer_set_time(GisViewer *viewer, const gchar *time);
+gchar *gis_viewer_get_time(GisViewer *viewer);
+
+void gis_viewer_set_location(GisViewer *viewer, gdouble lat, gdouble lon, gdouble elev);
+void gis_viewer_get_location(GisViewer *viewer, gdouble *lat, gdouble *lon, gdouble *elev);
+void gis_viewer_pan(GisViewer *viewer, gdouble forward, gdouble right, gdouble up);
+void gis_viewer_zoom(GisViewer *viewer, gdouble scale);
+
+void gis_viewer_set_rotation(GisViewer *viewer, gdouble x, gdouble y, gdouble z);
+void gis_viewer_get_rotation(GisViewer *viewer, gdouble *x, gdouble *y, gdouble *z);
+void gis_viewer_rotate (GisViewer *viewer, gdouble x, gdouble y, gdouble z);