Gets vertical skylines from grob stencils

lily/flag.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 15 matching lines @@
 #include "international.hh"
 #include "output-def.hh"
 #include "staff-symbol-referencer.hh"
 #include "stencil.hh"
 #include "warn.hh"
 
 class Flag
 {
 public:
   DECLARE_SCHEME_CALLBACK (print, (SCM));
+  DECLARE_SCHEME_CALLBACK (glyph_name, (SCM));
   DECLARE_SCHEME_CALLBACK (width, (SCM));
   DECLARE_SCHEME_CALLBACK (calc_y_offset, (SCM));
   DECLARE_SCHEME_CALLBACK (pure_calc_y_offset, (SCM, SCM, SCM));
   DECLARE_SCHEME_CALLBACK (calc_x_offset, (SCM));
   DECLARE_GROB_INTERFACE ();
 
   static SCM internal_calc_y_offset (SCM smob, bool pure);
 };
 
 MAKE_SCHEME_CALLBACK (Flag, width, 1);
 SCM
 Flag::width (SCM smob)
 {
   Grob *me = unsmob_grob (smob);
   Stencil *sten = unsmob_stencil (me->get_property ("stencil"));
   if (!sten)
     return ly_interval2scm (Interval (0.0, 0.0));
 
   Grob *stem = me->get_parent (X_AXIS);
 
   /*
     TODO:
     This reproduces a bad hard-coding that has been in the code for quite some time:
     the bounding boxes for the flags are slightly off and need to be fixed.
   */
 
   return ly_interval2scm (sten->extent (X_AXIS) - stem->extent (stem, X_AXIS)[RIGHT]);
 }
-MAKE_SCHEME_CALLBACK (Flag, print, 1);
-SCM
-Flag::print (SCM smob)
+
+MAKE_SCHEME_CALLBACK (Flag, glyph_name, 1);
+SCM
+Flag::glyph_name (SCM smob)
 {
   Grob *me = unsmob_grob (smob);
   Grob *stem = me->get_parent (X_AXIS);
 
   Direction d = get_grob_direction (stem);
   int log = Stem::duration_log (stem);
   string flag_style;
 
   SCM flag_style_scm = me->get_property ("style");
   if (scm_is_symbol (flag_style_scm))
     flag_style = ly_symbol2string (flag_style_scm);
-
-  if (flag_style == "no-flag")
-    return Stencil ().smobbed_copy ();
 
   bool adjust = true;
 
   string staffline_offs;
   if (flag_style == "mensural")
     /* Mensural notation: For notes on staff lines, use different
        flags than for notes between staff lines.  The idea is that
        flags are always vertically aligned with the staff lines,
        regardless if the note head is on a staff line or between two
        staff lines.  In other words, the inner end of a flag always
        touches a staff line.
     */
     {
       if (adjust)
         {
           Real ss = Staff_symbol_referencer::staff_space (me);
           int p = (int) (rint (stem->extent (stem, Y_AXIS)[d] * 2 / ss));
           staffline_offs
             = Staff_symbol_referencer::on_line (stem, p) ? "0" : "1";
         }
       else
         staffline_offs = "2";
     }
   else
     staffline_offs = "";
 
   char dir = (d == UP) ? 'u' : 'd';
   string font_char = flag_style
                      + to_string (dir) + staffline_offs + to_string (log);
+  return ly_string2scm ("flags." + font_char);
+}
+
+MAKE_SCHEME_CALLBACK (Flag, print, 1);
+SCM
+Flag::print (SCM smob)
+{
+  Grob *me = unsmob_grob (smob);
+  Grob *stem = me->get_parent (X_AXIS);
+
+  Direction d = get_grob_direction (stem);
+  string flag_style;
+
+  SCM flag_style_scm = me->get_property ("style");
+  if (scm_is_symbol (flag_style_scm))
+    flag_style = ly_symbol2string (flag_style_scm);
+
+  if (flag_style == "no-flag")
+    return Stencil ().smobbed_copy ();
+
+  char dir = (d == UP) ? 'u' : 'd';
   Font_metric *fm = Font_interface::get_default_font (me);
-  Stencil flag = fm->find_by_name ("flags." + font_char);
+  string font_char = robust_scm2string (me->get_property ("glyph-name"), "");
+  Stencil flag = fm->find_by_name (font_char);
   if (flag.is_empty ())
     me->warning (_f ("flag `%s' not found", font_char));
 
   /*
     TODO: maybe property stroke-style should take different values,
     e.g. "" (i.e. no stroke), "single" and "double" (currently, it's
     '() or "grace").  */
   SCM stroke_style_scm = me->get_property ("stroke-style");
   if (scm_is_string (stroke_style_scm))
     {
@@ skipping 61 matching lines @@
 
 ADD_INTERFACE (Flag,
                "A flag that gets attached to a stem."
                "The style property is  symbol determining"
                " what style of flag glyph is typeset on a"
                " @code{Stem}.  Valid options include @code{'()}"
                " for standard flags, @code{'mensural} and"
                " @code{'no-flag}, which switches off the flag.",
 
                /* properties */
+               "glyph-name "
                "style "
                "stroke-style "
               );