release: 1.5.29

[lilypond.git] / lily / rhythmic-column-engraver.cc

diff --git a/lily/rhythmic-column-engraver.cc b/lily/rhythmic-column-engraver.cc
index c87409c450567a0dc6311bc46077f85475362f4f..55462e76a970b4cba3b742d8523524b727d18a69 100644 (file)
--- a/lily/rhythmic-column-engraver.cc
+++ b/lily/rhythmic-column-engraver.cc
@@ -3,7 +3,7 @@
 
   source file of the GNU LilyPond music typesetter
 
-  (c)  1997--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  (c)  1997--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
 */
 
 
@@ -15,6 +15,35 @@
 #include "dot-column.hh"
 #include "musical-request.hh"
 #include "item.hh"
+#include "group-interface.hh"
+
+
+
+/*
+  this engraver  glues together stems, rests and note heads into a NoteColumn
+  grob.
+
+  It also generates spacing objects.  Originally, we have tried to
+  have the spacing functionality at different levels.
+  
+  - by simply using the sequence of Separation-item as
+  spacing-sequences (at staff level). Unfortunately, this fucks up if
+  there are different kinds of tuplets in different voices (8th and
+  8ths triplets combined made the program believe there were 1/12 th
+  notes.).
+
+  Doing it in a separate engraver using timing info is generally
+  complicated (start/end time management), and fucks up if a voice
+  changes staff.
+
+  Now we do it from here again. This has the problem that voices can
+  appear and disappear at will, leaving lots of loose ends (the note
+  spacing engraver don't know where to connect the last note of the
+  voice on the right with), but we don't complain about those, and let
+  the default spacing do its work.
+
+ */
+
 
 class Rhythmic_column_engraver :public Engraver
 {
@@ -59,14 +88,18 @@ Rhythmic_column_engraver::create_grobs ()
          Note_column::set_interface (note_column_);
          announce_grob (note_column_, 0);
 
-         spacing_ = new Item (get_property ("NoteSpacing"));
-         spacing_->set_grob_property ("left-item", note_column_->self_scm ());
-         announce_grob (spacing_, 0);
 
-         if (last_spacing_)
-           {
-             last_spacing_->set_grob_property ("right-item" , note_column_->self_scm ());
-           }
+         spacing_ = new Item (get_property ("NoteSpacing"));
+         spacing_->set_grob_property ("left-items", gh_cons (note_column_->self_scm (), SCM_EOL));
+         announce_grob (spacing_, 0);
+
+         if (last_spacing_)
+           {
+            Pointer_group_interface::add_grob (last_spacing_,
+                                               ly_symbol2scm ("right-items" ),
+                                               note_column_);
+           }
+
        }
 
       for (int i=0; i < rhead_l_arr_.size (); i++)
@@ -142,7 +175,7 @@ Rhythmic_column_engraver::start_translation_timestep ()
 
 ENTER_DESCRIPTION(Rhythmic_column_engraver,
 /* descr */       "Generates NoteColumn, an objects that groups stems, noteheads and rests.",
-/* creats*/       "NoteColumn",
+/* creats*/       "NoteColumn NoteSpacing",
 /* acks  */       "stem-interface rhythmic-head-interface dot-column-interface",
 /* reads */       "",
 /* write */       "");