2 note-spacing.cc -- implement Note_spacing
4 source file of the GNU LilyPond music typesetter
6 (c) 2001--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
9 #include "note-spacing.hh"
11 #include "directional-element-interface.hh"
12 #include "grob-array.hh"
13 #include "paper-column.hh"
15 #include "note-column.hh"
18 #include "separation-item.hh"
19 #include "spacing-interface.hh"
20 #include "staff-spacing.hh"
21 #include "accidental-placement.hh"
22 #include "output-def.hh"
23 #include "pointer-group-interface.hh"
26 TODO: detect hshifts due to collisions, and account for them in
31 Note_spacing::get_spacing (Grob *me, Item *right_col,
32 Real base_space, Real increment)
34 vector<Item*> note_columns = Spacing_interface::left_note_columns (me);
35 Real left_head_end = 0;
37 for (vsize i = 0; i < note_columns.size (); i++)
39 SCM r = note_columns[i]->get_object ("rest");
40 Grob *g = unsmob_grob (r);
41 Grob *col = note_columns[i]->get_column ();
44 g = Note_column::first_head (note_columns[i]);
47 Ugh. If Stem is switched off, we don't know what the
48 first note head will be.
52 if (g->common_refpoint (col, X_AXIS) != col)
53 programming_error ("Note_spacing::get_spacing (): Common refpoint incorrect");
55 left_head_end = g->extent (col, X_AXIS)[RIGHT];
60 We look at the width of the note head, since smaller heads get less space
62 eg. a quarter rest gets almost 0.5 ss less horizontal space than a note.
64 What is sticking out of the note head (eg. a flag), doesn't get
65 the full amount of space.
67 Real min_dist = Spacing_interface::minimum_distance (me);
68 Real min_desired_space = max (left_head_end + (min_dist - left_head_end) / 2,
69 min_dist - (base_space - increment) / 2);
70 Real ideal = base_space - increment + min_desired_space;
72 stem_dir_correction (me, right_col, increment, &ideal, &min_desired_space);
74 Spring ret (ideal, min_dist);
75 ret.set_inverse_compress_strength (ideal - max (min_dist, min_desired_space));
81 Correct for optical illusions. See [Wanske] p. 138. The combination
82 up-stem + down-stem should get extra space, the combination
83 down-stem + up-stem less.
85 TODO: have to check whether the stems are in the same staff.
88 Note_spacing::stem_dir_correction (Grob *me, Item *rcolumn,
90 Real *space, Real *fixed)
92 Drul_array<Direction> stem_dirs (CENTER, CENTER);
93 Drul_array<Interval> stem_posns;
94 Drul_array<Interval> head_posns;
95 Drul_array<SCM> props (me->get_object ("left-items"),
96 me->get_object ("right-items"));
98 Drul_array<Spanner *> beams_drul (0, 0);
99 Drul_array<Grob *> stems_drul (0, 0);
101 stem_dirs[LEFT] = stem_dirs[RIGHT] = CENTER;
103 Interval bar_xextent;
104 Interval bar_yextent;
106 bool correct_stem_dirs = true;
108 bool acc_right = false;
112 vector<Grob*> const &items (ly_scm2link_array (props [d]));
113 for (vsize i = 0; i < items.size (); i++)
115 Item *it = dynamic_cast<Item *> (items[i]);
118 acc_right = acc_right || Note_column::accidentals (it);
120 Grob *stem = Note_column::get_stem (it);
122 if (!stem || !stem->is_live ())
124 if (d == RIGHT && Separation_item::has_interface (it))
126 if (it->get_column () != rcolumn)
127 it = it->find_prebroken_piece (rcolumn->break_status_dir ());
129 Grob *last = Separation_item::extremal_break_aligned_grob (it, LEFT, &bar_xextent);
132 bar_yextent = Staff_spacing::bar_y_positions (last);
140 if (Stem::is_invisible (stem))
142 correct_stem_dirs = false;
146 stems_drul[d] = stem;
147 beams_drul[d] = Stem::get_beam (stem);
149 Direction stem_dir = get_grob_direction (stem);
150 if (stem_dirs[d] && stem_dirs[d] != stem_dir)
152 correct_stem_dirs = false;
155 stem_dirs[d] = stem_dir;
158 Correction doesn't seem appropriate when there is a large flag
159 hanging from the note.
162 && Stem::duration_log (stem) > 2 && !Stem::get_beam (stem))
163 correct_stem_dirs = false;
165 Interval hp = Stem::head_positions (stem);
166 if (correct_stem_dirs
169 Real chord_start = hp[stem_dir];
172 can't look at stem-end-position, since that triggers
173 beam slope computations.
175 Real stem_end = hp[stem_dir] +
176 stem_dir * robust_scm2double (stem->get_property ("length"), 7);
178 stem_posns[d] = Interval (min (chord_start, stem_end),
179 max (chord_start, stem_end));
180 head_posns[d].unite (hp);
184 while (flip (&d) != LEFT);
187 don't correct if accidentals are sticking out of the right side.
192 Real correction = 0.0;
194 if (!bar_yextent.is_empty ())
196 stem_dirs[RIGHT] = -stem_dirs[LEFT];
197 stem_posns[RIGHT] = bar_yextent;
198 stem_posns[RIGHT] *= 2;
201 if (correct_stem_dirs && stem_dirs[LEFT] * stem_dirs[RIGHT] == -1)
203 if (beams_drul[LEFT] && beams_drul[LEFT] == beams_drul[RIGHT])
207 this is a knee: maximal correction.
209 Real note_head_width = increment;
210 Grob *st = stems_drul[RIGHT];
211 Grob *head = st ? Stem::support_head (st) : 0;
213 Interval head_extent;
216 head_extent = head->extent (rcolumn, X_AXIS);
218 if (!head_extent.is_empty ())
219 note_head_width = head_extent[RIGHT];
221 note_head_width -= Stem::thickness (st);
224 correction = note_head_width * stem_dirs[LEFT];
225 correction *= robust_scm2double (me->get_property ("knee-spacing-correction"), 0);
226 *fixed += correction;
230 intersect = stem_posns[LEFT];
231 intersect.intersect (stem_posns[RIGHT]);
232 correct_stem_dirs = correct_stem_dirs && !intersect.is_empty ();
234 if (correct_stem_dirs)
236 correction = abs (intersect.length ());
241 correction = min (correction / 7, 1.0);
242 correction *= stem_dirs[LEFT];
244 *= robust_scm2double (me->get_property ("stem-spacing-correction"), 0);
247 if (!bar_yextent.is_empty ())
251 else if (correct_stem_dirs && stem_dirs[LEFT] * stem_dirs[RIGHT] == UP)
254 Correct for the following situation:
263 ^ move the center one to the left.
266 this effect seems to be much more subtle than the
267 stem-direction stuff (why?), and also does not scale with the
268 difference in stem length.
272 Interval hp = head_posns[LEFT];
273 hp.intersect (head_posns[RIGHT]);
278 = (head_posns[LEFT][DOWN] > head_posns[RIGHT][UP]) ? RIGHT : LEFT;
280 Real delta = head_posns[-lowest][DOWN] - head_posns[lowest][UP];
281 Real corr = robust_scm2double (me->get_property ("same-direction-correction"), 0);
284 correction = -lowest * corr;
287 *space += correction;
289 /* there used to be a correction for bar_xextent () here, but
290 it's unclear what that was good for ?
294 ADD_INTERFACE (Note_spacing,
295 "This object calculates spacing wishes for individual voices.",
298 "knee-spacing-correction "
301 "same-direction-correction "
302 "stem-spacing-correction "