+MAKE_SCHEME_CALLBACK(Dot_column, calc_positioning_done, 1);
+SCM
+Dot_column::calc_positioning_done (SCM smob)
+{
+ Grob *me = unsmob_grob (smob);
+ vector<Grob*> dots
+ = extract_grob_array (me, "dots");
+
+ { /*
+ Trigger note collision resolution first, since that may kill off
+ dots when merging.
+ */
+ Grob *c = 0;
+ for (vsize i = dots.size (); i--;)
+ {
+ Grob *n = dots[i]->get_parent (Y_AXIS);
+ if (c)
+ c = n->common_refpoint (c, X_AXIS);
+ else
+ c = n;
+ }
+ for (vsize i = dots.size (); i--;)
+ {
+ Grob *n = dots[i]->get_parent (Y_AXIS);
+ n->relative_coordinate (c, X_AXIS);
+ }
+ }
+
+ vector_sort (dots, position_less);
+ for (vsize i = dots.size (); i--;)
+ if (!dots[i]->is_live ())
+ dots.erase (dots.begin () + i);
+
+ Dot_configuration cfg;
+ for (vsize i = 0;i < dots.size (); i++)
+ {
+ Dot_position dp;
+ dp.dot_ = dots[i];
+
+ Grob *note = dots[i]->get_parent (Y_AXIS);
+ if (note)
+ {
+ Grob *stem = unsmob_grob (note->get_object ("stem"));
+ if (stem)
+ dp.extremal_head_ = Stem::first_head (stem) == note;
+ }
+
+ int p = Staff_symbol_referencer::get_rounded_position (dp.dot_);
+ dp.pos_ = p;
+
+ if (dp.extremal_head_)
+ dp.dir_ = to_dir (dp.dot_->get_property ("direction"));