2 spacing-basic.cc -- implement Spacing_spanner, simplistic spacing routines
4 source file of the GNU LilyPond music typesetter
6 (c) 2005 Han-Wen Nienhuys <hanwen@xs4all.nl>
10 #include "spacing-spanner.hh"
12 #include "paper-column.hh"
17 LilyPond spaces by taking a simple-minded spacing algorithm, and
18 adding subtle adjustments to that. This file does the simple-minded
24 Get the measure wide ant for arithmetic spacing.
27 Spacing_options::get_duration_space (Moment d,
28 bool *expand_only) const
30 Real k = shortest_duration_space_;
32 if (d < global_shortest_)
35 We don't space really short notes using the log of the
36 duration, since it would disproportionally stretches the long
37 notes in a piece. In stead, we use geometric spacing with constant 0.5
40 This should probably be tunable, to use other base numbers.
42 In Mozart hrn3 by EB., we have 8th note = 3.9 mm (total), 16th note =
43 3.6 mm (total). head-width = 2.4, so we 1.2mm for 16th, 1.5
44 mm for 8th. (white space), suggesting that we use
46 (1.2 / 1.5)^{-log2(duration ratio)}
50 Rational ratio = d.main_part_ / global_shortest_;
52 return ((k - 1) + double (ratio)) * increment_;
57 John S. Gourlay. ``Spacing a Line of Music, '' Technical
58 Report OSU-CISRC-10/87-TR35, Department of Computer and
59 Information Science, The Ohio State University, 1987.
61 Real log = log_2 (global_shortest_);
63 Rational compdur = d.main_part_ + d.grace_part_ / Rational (3);
66 return (log_2 (compdur) + k) * increment_;
72 The one-size-fits all spacing. It doesn't take into account
73 different spacing wishes from one to the next column.
76 Spacing_spanner::standard_breakable_column_spacing (Grob *me, Item *l, Item *r,
77 Real *fixed, Real *space,
78 Spacing_options const *options)
82 Drul_array<Item *> cols (l, r);
86 if (!Paper_column::is_musical (cols[d]))
89 Tied accidentals over barlines cause problems, so lets see
90 what happens if we do this for non musical columns only.
92 Interval lext = cols[d]->extent (cols [d], X_AXIS);
93 if (!lext.is_empty ())
94 *fixed += -d * lext[-d];
97 while (flip (&d) != LEFT);
99 if (l->is_breakable (l) && r->is_breakable (r))
101 Moment *dt = unsmob_moment (l->get_property ("measure-length"));
106 Real incr = robust_scm2double (me->get_property ("spacing-increment"), 1);
108 *space = *fixed + incr * double (mlen.main_part_ / options->global_shortest_) * 0.8;
112 Moment dt = Paper_column::when_mom (r) - Paper_column::when_mom (l);
114 if (dt == Moment (0, 0))
117 In this case, Staff_spacing should handle the job,
118 using dt when it is 0 is silly.
120 *space = *fixed + 0.5;
125 *space = *fixed + options->get_duration_space (dt, &dummy);
131 Spacing_spanner::note_spacing (Grob *me, Grob *lc, Grob *rc,
132 Spacing_options const *options ,
135 Moment shortest_playing_len = 0;
136 SCM s = lc->get_property ("shortest-playing-duration");
138 if (unsmob_moment (s))
139 shortest_playing_len = *unsmob_moment (s);
141 if (! shortest_playing_len.to_bool ())
143 programming_error ("can't find a ruling note at " + Paper_column::when_mom (lc).to_string ());
144 shortest_playing_len = 1;
147 Moment lwhen = Paper_column::when_mom (lc);
148 Moment rwhen = Paper_column::when_mom (rc);
150 Moment delta_t = rwhen - lwhen;
151 if (!Paper_column::is_musical (rc))
154 when toying with mmrests, it is possible to have musical
155 column on the left and non-musical on the right, spanning
159 Moment *dt = unsmob_moment (rc->get_property ("measure-length"));
162 delta_t = min (delta_t, *dt);
165 The following is an extra safety measure, such that
166 the length of a mmrest event doesn't cause havoc.
168 shortest_playing_len = min (shortest_playing_len, *dt);
173 if (delta_t.main_part_ && !lwhen.grace_part_)
175 dist = options->get_duration_space (shortest_playing_len,
177 dist *= double (delta_t.main_part_ / shortest_playing_len.main_part_);
179 else if (delta_t.grace_part_)
182 Crude hack for spacing graces: we take the shortest space
183 available (namely the space for the global shortest note), and
184 multiply that by grace-space-factor
186 dist = options->get_duration_space (options->global_shortest_, expand_only);
189 = robust_scm2double (me->get_property ("grace-space-factor"), 1);
198 /****************************************************************/
201 Spacing_options::init_from_grob (Grob *me)
203 increment_ = robust_scm2double (me->get_property ("spacing-increment"), 1);
205 packed_ = to_boolean (me->get_property ("packed-spacing"));
206 stretch_uniformly_ = to_boolean (me->get_property ("uniform-stretching"));
207 float_nonmusical_columns_
208 = to_boolean (me->get_property ("strict-note-spacing"));
209 shortest_duration_space_ = robust_scm2double (me->get_property ("shortest-duration-space"), 1);
214 Spacing_options::init ()
218 stretch_uniformly_ = false;
219 float_nonmusical_columns_ = false;
220 shortest_duration_space_ = 2.0;
222 global_shortest_ = Rational (1,8);