+
+ Grob *commonx = bound[LEFT]->common_refpoint (bound[RIGHT], X_AXIS);
+ commonx = me->common_refpoint (commonx, X_AXIS);
+
+ Grob *next_common_y = line_spanner_common_parent (next_bound);
+ Grob *this_common_y = line_spanner_common_parent (bound[LEFT]);
+
+ Grob *all_common_y = me->common_refpoint (this_common_y, Y_AXIS);
+
+ Interval next_ext = next_bound->extent (next_common_y, Y_AXIS);
+ Interval this_ext = bound[LEFT]->extent (this_common_y, Y_AXIS);
+
+ Real yoff = this_common_y->relative_coordinate (all_common_y, Y_AXIS);
+
+ Offset p1 (bound[LEFT]->extent (commonx, X_AXIS)[RIGHT],
+ this_ext.center () + yoff);
+ Offset p2 (bound[RIGHT]->extent (commonx, X_AXIS)[LEFT],
+ next_ext.center () + yoff);
+
+ Offset dz (p2 -p1);
+ Real len = dz.length ();
+
+ Offset dir = dz * (1 / len);
+ dz = (dz.length () - 2 * gap) * dir;
+
+ Stencil l (line_stencil (me, Offset (0, 0), dz));
+
+ l.translate (dir * gap + p1
+ - Offset (me->relative_coordinate (commonx, X_AXIS),
+ me->relative_coordinate (all_common_y, Y_AXIS)));
+
+ return l.smobbed_copy ();