Issue 5167/6: Changes: show \markup xxx = ... \etc assignments

[lilypond.git] / lily / spacing-options.cc

diff --git a/lily/spacing-options.cc b/lily/spacing-options.cc
index 7a038eb25b38fdd7da6fc85c47af952b5d64acc5..dbf0587acdd7e6e98ae9110516d07a7b8cee222d 100644 (file)
--- a/lily/spacing-options.cc
+++ b/lily/spacing-options.cc
@@ -1,14 +1,29 @@
 /*
-  spacing-options.cc -- implement Spacing_options 
+  This file is part of LilyPond, the GNU music typesetter.
 
-  source file of the GNU LilyPond music typesetter
+  Copyright (C) 2006--2015 Han-Wen Nienhuys <hanwen@lilypond.org>
 
-  (c) 2006 Han-Wen Nienhuys <hanwen@lilypond.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.
+
+  LilyPond is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include "spacing-options.hh"
 #include "spacing-spanner.hh"
 #include "grob.hh"
+#include "misc.hh"
+#include "moment.hh"
+#include "spanner.hh"
 
 void
 Spacing_options::init_from_grob (Grob *me)
@@ -22,16 +37,67 @@ Spacing_options::init_from_grob (Grob *me)
   float_grace_columns_
     = to_boolean (me->get_property ("strict-grace-spacing"));
   shortest_duration_space_ = robust_scm2double (me->get_property ("shortest-duration-space"), 1);
+
+  Moment shortest_dur = robust_scm2moment (me->get_property ("common-shortest-duration"),
+                                           Moment (Rational (1, 8), Rational (1, 16)));
+
+  if (shortest_dur.main_part_)
+    global_shortest_ = shortest_dur.main_part_;
+  else
+    global_shortest_ = shortest_dur.grace_part_;
 }
 
 Spacing_options::Spacing_options ()
 {
-  increment_ = 1.2;
   packed_ = false;
   stretch_uniformly_ = false;
   float_nonmusical_columns_ = false;
   float_grace_columns_ = false;
+
   shortest_duration_space_ = 2.0;
+  increment_ = 1.2;
 
   global_shortest_ = Rational (1, 8);
 }
+
+/*
+  Get the measure wide ant for arithmetic spacing.
+*/
+Real
+Spacing_options::get_duration_space (Rational d) const
+{
+  Real ratio = d / global_shortest_;
+
+  if (ratio < 1.0)
+    {
+      /*
+        We don't space really short notes using the log of the
+        duration, since it would disproportionally stretches the long
+        notes in a piece. In stead, we use geometric spacing with constant 0.5
+        (i.e. linear.)
+
+        This should probably be tunable, to use other base numbers.
+
+        In Mozart hrn3 by EB., we have 8th note = 3.9 mm (total), 16th note =
+        3.6 mm (total).  head-width = 2.4, so we 1.2mm for 16th, 1.5
+        mm for 8th. (white space), suggesting that we use
+
+        (1.2 / 1.5)^{-log2(duration ratio)}
+
+
+      */
+
+      return (shortest_duration_space_ + ratio - 1) * increment_;
+    }
+  else
+    {
+      /*
+        John S. Gourlay. ``Spacing a Line of Music, '' Technical
+        Report OSU-CISRC-10/87-TR35, Department of Computer and
+        Information Science, The Ohio State University, 1987.
+      */
+
+      return (shortest_duration_space_ + log_2 (ratio)) * increment_;
+    }
+}
+