+ Spanner *me = dynamic_cast<Spanner *> (Grob::unsmob (grob));
+
+ SCM which = me->get_property ("style");
+ Real height = robust_scm2double (me->get_property ("height"), 1);
+
+ Real t = Staff_symbol_referencer::line_thickness (me) * robust_scm2double (me->get_property ("thickness"), 1);
+ Grob *common = me->get_bound (LEFT)->common_refpoint (me->get_bound (RIGHT),
+ X_AXIS);
+
+ Real right_point = robust_relative_extent (me->get_bound (RIGHT),
+ common, X_AXIS).linear_combination (CENTER);
+ Real left_point = me->get_bound (LEFT)->relative_coordinate (common, X_AXIS);
+
+ Interval iv (left_point, right_point);
+ Stencil m;