Adds glissando stems to Lilypond.

lily/script-interface.cc

 /*
   This file is part of LilyPond, the GNU music typesetter.
 
   Copyright (C) 1999--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
   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 60 matching lines @@
   SCM reldir = me->get_property ("side-relative-direction");
   if (is_direction (reldir))
     relative_dir = to_dir (reldir);
 
   SCM other_elt = me->get_object ("direction-source");
   Grob *e = unsmob_grob (other_elt);
   if (e)
     return (Direction) (relative_dir * get_grob_direction (e));
 
   return CENTER;
+}
+
+MAKE_SCHEME_CALLBACK (Script_interface, calc_opposite_direction, 1);
+SCM
+Script_interface::calc_opposite_direction (SCM smob)
+{
+  return scm_product (scm_from_int (-1), calc_direction (smob));
 }
 
 MAKE_SCHEME_CALLBACK (Script_interface, calc_direction, 1);
 SCM
 Script_interface::calc_direction (SCM smob)
 {
   Grob *me = unsmob_grob (smob);
   Direction d = Script_interface::get_direction (me);
 
   if (!d)
@@ skipping 65 matching lines @@
                "direction-source "
                "positioning-done "
                "script-priority "
                "script-stencil "
                "side-relative-direction "
                "slur "
                "slur-padding "
                "toward-stem-shift "
                );