+ Grob *me = unsmob_grob (element_smob);
+ Axis a = (Axis) gh_scm2int (axis);
+ assert (a == Y_AXIS);
+ Interval i (get_spanned_interval (me));
+
+ /*
+ Bar::brew_molecule delivers a barline of y-extent (-h/2,h/2), so
+ we have to translate ourselves to be in the center of the
+ interval that we span. */
+ if (i.empty_b ())
+ {
+ me->suicide();
+ return gh_double2scm (0.0);
+ }