Merging different fonts

[Doug Linhardt]

When running lilypond (I'm using 2.1.27), if you have 2 voices with 
different note head styles (fonts), the program will merge colliding 
notes, losing one of the fonts.  The problem is shown in this example:

\score { \notes { << { d'4 c'4 }
       \\ \override NoteHead #'style = #'diamond
       { c'4 c'4 } >> r2 } }
\paper {
   indent = 0.0\mm
   raggedright = ##t
}


I created a patch.  I also added a property (merge-differently-fonted) 
to allow the original behavior.  The patch includes the source files as 
well as the user manual.  I also created a file for the regression 
tests.  Below are the 1. the patch, and 2. the regression test.  I've 
been following the mailing list for a few weeks now, and I think this is 
the format you want (diff -u, no attachments, etc.).  If you want 
something else, let me know.

Doug Linhardt

1. The patch

--- ../lilypond-2.1.27/./lily/note-head.cc      2004-03-07 
17:03:28.000000000 -0600
+++ ./lily/note-head.cc 2004-03-07 17:03:28.000000000 -0600
@@ -121,16 +121,13 @@
Stencil
internal_print (Grob *me, bool with_ledgers)
{
-  SCM style  = me->get_property ("style");
-  if (!gh_symbol_p (style))
+  String font_name = Note_head::get_font_name(me);
+  if (font_name == "")
    {
      return Stencil ();
    }

-  SCM log = gh_int2scm (Note_head::get_balltype (me));
-  SCM proc = me->get_property ("glyph-name-procedure");
-  SCM scm_font_char = scm_call_2 (proc, log, style);
-  String font_char = "noteheads-" + ly_scm2string (scm_font_char);
+  String font_char = "noteheads-" + font_name;

  Font_metric * fm = Font_interface::get_default_font (me);
  Stencil out = fm->find_by_name (font_char);
@@ -272,6 +269,23 @@
  return m.smobbed_copy ();
}

+String
+Note_head::get_font_name(Grob* me)
+{
+  String ret_val = "";
+
+  SCM style  = me->get_property ("style");
+  if (gh_symbol_p (style))
+    {
+      SCM log = gh_int2scm (Note_head::get_balltype (me));
+      SCM proc = me->get_property ("glyph-name-procedure");
+      SCM scm_font_char = scm_call_2 (proc, log, style);
+      ret_val = ly_scm2string (scm_font_char);
+    }
+
+ return ret_val;
+}
+

Real
Note_head::stem_attachment_coordinate (Grob *me, Axis a)
@@ -281,16 +295,13 @@
  
  if (brewer == Note_head::print_proc)
    {
-      SCM style  = me->get_property ("style");
-      if (!gh_symbol_p (style))
-       {
-         return 0.0;
-       }
-
-      SCM log = gh_int2scm (Note_head::get_balltype (me));
-      SCM proc = me->get_property ("glyph-name-procedure");
-      SCM scm_font_char = scm_call_2 (proc, log, style);
-      String font_char = "noteheads-" + ly_scm2string (scm_font_char);
+      String font_name = get_font_name(me);
+      if (font_name == "")
+        {
+          return 0.0;
+        }
+
+      String font_char = "noteheads-" + font_name;

      int k = fm->name_to_index (font_char) ;

--- ../lilypond-2.1.27/./lily/note-collision.cc 2004-03-07 
17:03:28.000000000 -0600
+++ ./lily/note-collision.cc    2004-03-07 17:03:28.000000000 -0600
@@ -71,6 +71,8 @@

  int upball_type = Note_head::get_balltype (nu);
  int dnball_type = Note_head::get_balltype (nd);
+  String up_font = Note_head::get_font_name (nu);
+  String dn_font = Note_head::get_font_name (nd);
  
  /* Do not merge whole notes (or longer, like breve, longa, maxima).  */
  if (merge_possible && (upball_type <= 0 || dnball_type <= 0))
@@ -88,6 +90,13 @@
      && !to_boolean (me->get_property ("merge-differently-headed")))
    merge_possible = false;

+  /* Can only merge different fonts if merge-differently-fonted is
+     set. */
+  if (merge_possible
+      && up_font != dn_font
+      && !to_boolean (me->get_property ("merge-differently-fonted")))
+    merge_possible = false;
+
  /* Should never merge quarter and half notes, as this would make
     them indistinguishable.  */
  if (merge_possible
@@ -474,4 +483,4 @@

              ,
              
-              "merge-differently-dotted merge-differently-headed 
positioning-done");
+              "merge-differently-dotted merge-differently-headed 
merge-differently-fonted positioning-done");
--- ../lilypond-2.1.27/./lily/include/note-head.hh      2004-03-07 
17:03:28.000000000 -0600
+++ ./lily/include/note-head.hh 2004-03-07 17:03:28.000000000 -0600
@@ -29,6 +29,7 @@
  static bool has_interface (Grob*);
  static Real stem_attachment_coordinate (Grob *, Axis a);
  static int get_balltype (Grob*) ;
+  static String get_font_name (Grob*) ;
};
#endif // NOTEHEAD_HH

--- ../lilypond-2.1.27/./scm/define-grob-properties.scm 2004-03-07 
17:03:28.000000000 -0600
+++ ./scm/define-grob-properties.scm    2004-03-07 17:03:28.000000000 -0600
@@ -338,6 +338,10 @@
notation for some types of polyphonic music. The value of this setting
is used by @internalsref{note-collision-interface} .")

+     (merge-differently-fonted ,boolean? "Merge noteheads in
+collisions, even if they are represented by different fonts.  The value
+of this setting is used by @internalsref{note-collision-interface} .")
+
     (minimum-distance ,ly:dimension? "Minimum distance between rest
and notes or beam.")
     (minimum-X-extent ,number-pair? "Minimum size of an object in X
--- ../lilypond-2.1.27/./Documentation/user/refman.itely        
2004-03-07 17:03:28.000000000 -0600
+++ ./Documentation/user/refman.itely   2004-03-07 17:03:28.000000000 -0600
@@ -1240,6 +1240,15 @@
    c8 c4. } \\ { c2 c2 } >>
@end lilypond

+Also, you can merge note heads from different fonts, by setting
address@hidden:
address@hidden,relative=2,verbatim]
+\context Voice << { c4 c4 }
+    \\ \override NoteHead #'style = #'diamond
+    {c4 \override Staff.NoteCollision
+    #'merge-differently-fonted = ##t c4 } >>
address@hidden lilypond
+
LilyPond also vertically shifts rests that are opposite of a stem:


======================

2.  The regression test

File name: collision-merge-differently-fonted.ly

\version "2.1.27"
\header {
   
   texidoc = "If NoteCollision has merge-differently-fonted = ##t note
heads that have fonts may be merged anyway."
   
}

\paper { raggedright= ##t }

\score {
   \context Staff \notes\relative c'' <<
       {
           c4
           \override Staff.NoteCollision  #'merge-differently-fonted = ##t
           c4
       }
   \\
       \override NoteHead #'style = #'diamond
       {
           c4 c4
       }
   >>
}