Approximates cross-staff slurs in VerticalAxisGroup vertical-skylines.

lily/slur.cc

 /*
   This file is part of LilyPond, the GNU music typesetter.
 
   Copyright (C) 1996--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
   Jan Nieuwenhuizen <janneke@gnu.org>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
@@ skipping 233 matching lines @@
   Pointer_group_interface::add_grob (me, ly_symbol2scm ("note-columns"), n);
   add_bound_item (dynamic_cast<Spanner *> (me), n);
 }
 
 void
 Slur::add_extra_encompass (Grob *me, Grob *n)
 {
   Pointer_group_interface::add_grob (me, ly_symbol2scm ("encompass-objects"), n);
 }
 
+void
+Slur::main_to_stub (Grob *main, Grob *stub)
+{
+  extract_grob_set (main, "note-columns", nc);
+  for (vsize i = 0; i < nc.size (); i++)
+    add_column (stub, nc[i]);
+
+  extract_grob_set (main, "encompass-objects", eo);
+  for (vsize i = 0; i < eo.size (); i++)
+    add_extra_encompass (stub, eo[i]);
+
+  stub->set_object ("surrogate", main->self_scm ());
+
+  dynamic_cast<Spanner *> (stub)->set_bound
+    (LEFT, dynamic_cast<Spanner *> (main)->get_bound (LEFT));
+  dynamic_cast<Spanner *> (stub)->set_bound
+    (RIGHT, dynamic_cast<Spanner *> (main)->get_bound (RIGHT));
+}
+
+MAKE_SCHEME_CALLBACK (Slur, direction_from_shadowed_slur, 1);
+SCM
+Slur::direction_from_shadowed_slur (SCM smob)
+{
+  Grob *me = unsmob_grob (smob);
+  if (Grob *slur = unsmob_grob (me->get_object ("surrogate")))
+    return scm_from_int (get_grob_direction (slur));
+
+  me->programming_error ("Cannot determine SlurStub direction");
+
+  return scm_from_int (UP);
+}
+
 MAKE_SCHEME_CALLBACK_WITH_OPTARGS (Slur, pure_outside_slur_callback, 4, 1, "");
 SCM
 Slur::pure_outside_slur_callback (SCM grob, SCM start_scm, SCM end_scm, SCM offset_scm)
 {
   int start = robust_scm2int (start_scm, 0);
   int end = robust_scm2int (end_scm, 0);
   Grob *script = unsmob_grob (grob);
   Grob *slur = unsmob_grob (script->get_object ("slur"));
   if (!slur)
     return offset_scm;
@@ skipping 116 matching lines @@
     {
       Box b;
       b.add_point (curve.curve_point (i * 1.0 / box_count));
       b.add_point (curve.curve_point ((i + 1) * 1.0 / box_count));
       boxes.push_back (b);
     }
 
   return Skyline_pair (boxes, X_AXIS).smobbed_copy ();
 }
 
+MAKE_SCHEME_CALLBACK (Slur, extremal_stub_vertical_skylines, 1);
+SCM
+Slur::extremal_stub_vertical_skylines (SCM smob)
+{
+  Grob *me = unsmob_grob (smob);
+  vector<int> vais;
+  extract_grob_set (me, "note-columns", note_columns);
+  for (vsize i = 0; i < note_columns.size (); i++)
+    vais.push_back (Grob::get_vertical_axis_group_index (note_columns[i]));
+
+  vector_sort (vais, less<int> ());
+  int my_vai = Grob::get_vertical_axis_group_index (me);
+  if (!(my_vai == vais[0] || my_vai == vais.back ()))
+    return Skyline_pair ().smobbed_copy ();
+
+  Skyline_pair sky = *Skyline_pair::unsmob (vertical_skylines (smob));
+  if (my_vai == vais[0])
+    sky[DOWN] = Skyline ();
+  else
+    sky[UP] = Skyline ();
+
+  return sky.smobbed_copy ();
+}
+
 /*
  * Used by Slur_engraver:: and Phrasing_slur_engraver::
  */
 void
 Slur::auxiliary_acknowledge_extra_object (Grob_info const &info,
                                           vector<Grob *> &slurs,
                                           vector<Grob *> &end_slurs)
 {
   if (slurs.empty () && end_slurs.empty ())
     return;
@@ skipping 157 matching lines @@
                "direction "
                "eccentricity "
                "encompass-objects "
                "height-limit "
                "inspect-quants "
                "inspect-index "
                "line-thickness "
                "note-columns "
                "positions "
                "ratio "
                "thickness "

[dak, 2012/09/02 15:59:00]

No entry for "surrogate"?

[MikeSol, 2012/09/02 16:45:14]

scm/define-grob-interfaces.scm

               );