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, Real *space, Real *fixed)
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);
69 *fixed = max (left_head_end + (min_dist - left_head_end) / 2,
70 min_dist - (base_space - increment) / 2);
73 We don't do complicated stuff: (base_space - increment) is the
74 normal amount of white, which also determines the amount of
75 stretch. Upon (extreme) stretching, notes with accidentals should
76 stretch as much as notes without accidentals.
78 *space = (base_space - increment) + *fixed;
80 stem_dir_correction (me, right_col, increment, space, fixed);
85 Correct for optical illusions. See [Wanske] p. 138. The combination
86 up-stem + down-stem should get extra space, the combination
87 down-stem + up-stem less.
89 TODO: have to check whether the stems are in the same staff.
92 Note_spacing::stem_dir_correction (Grob *me, Item *rcolumn,
94 Real *space, Real *fixed)
96 Drul_array<Direction> stem_dirs (CENTER, CENTER);
97 Drul_array<Interval> stem_posns;
98 Drul_array<Interval> head_posns;
99 Drul_array<SCM> props (me->get_object ("left-items"),
100 me->get_object ("right-items"));
102 Drul_array<Spanner *> beams_drul (0, 0);
103 Drul_array<Grob *> stems_drul (0, 0);
105 stem_dirs[LEFT] = stem_dirs[RIGHT] = CENTER;
107 Interval bar_xextent;
108 Interval bar_yextent;
110 bool correct_stem_dirs = true;
112 bool acc_right = false;
116 vector<Grob*> const &items (ly_scm2link_array (props [d]));
117 for (vsize i = 0; i < items.size (); i++)
119 Item *it = dynamic_cast<Item *> (items[i]);
122 acc_right = acc_right || Note_column::accidentals (it);
124 Grob *stem = Note_column::get_stem (it);
126 if (!stem || !stem->is_live ())
128 if (d == RIGHT && Separation_item::has_interface (it))
130 if (it->get_column () != rcolumn)
131 it = it->find_prebroken_piece (rcolumn->break_status_dir ());
133 Grob *last = Separation_item::extremal_break_aligned_grob (it, LEFT, &bar_xextent);
136 bar_yextent = Staff_spacing::bar_y_positions (last);
144 if (Stem::is_invisible (stem))
146 correct_stem_dirs = false;
150 stems_drul[d] = stem;
151 beams_drul[d] = Stem::get_beam (stem);
153 Direction stem_dir = get_grob_direction (stem);
154 if (stem_dirs[d] && stem_dirs[d] != stem_dir)
156 correct_stem_dirs = false;
159 stem_dirs[d] = stem_dir;
162 Correction doesn't seem appropriate when there is a large flag
163 hanging from the note.
166 && Stem::duration_log (stem) > 2 && !Stem::get_beam (stem))
167 correct_stem_dirs = false;
169 Interval hp = Stem::head_positions (stem);
170 if (correct_stem_dirs
173 Real chord_start = hp[stem_dir];
176 can't look at stem-end-position, since that triggers
177 beam slope computations.
179 Real stem_end = hp[stem_dir] +
180 stem_dir * robust_scm2double (stem->get_property ("length"), 7);
182 stem_posns[d] = Interval (min (chord_start, stem_end),
183 max (chord_start, stem_end));
184 head_posns[d].unite (hp);
188 while (flip (&d) != LEFT);
191 don't correct if accidentals are sticking out of the right side.
196 Real correction = 0.0;
198 if (!bar_yextent.is_empty ())
200 stem_dirs[RIGHT] = -stem_dirs[LEFT];
201 stem_posns[RIGHT] = bar_yextent;
202 stem_posns[RIGHT] *= 2;
205 if (correct_stem_dirs && stem_dirs[LEFT] * stem_dirs[RIGHT] == -1)
207 if (beams_drul[LEFT] && beams_drul[LEFT] == beams_drul[RIGHT])
211 this is a knee: maximal correction.
213 Real note_head_width = increment;
214 Grob *st = stems_drul[RIGHT];
215 Grob *head = st ? Stem::support_head (st) : 0;
217 Interval head_extent;
220 head_extent = head->extent (rcolumn, X_AXIS);
222 if (!head_extent.is_empty ())
223 note_head_width = head_extent[RIGHT];
225 note_head_width -= Stem::thickness (st);
228 correction = note_head_width * stem_dirs[LEFT];
229 correction *= robust_scm2double (me->get_property ("knee-spacing-correction"), 0);
230 *fixed += correction;
234 intersect = stem_posns[LEFT];
235 intersect.intersect (stem_posns[RIGHT]);
236 correct_stem_dirs = correct_stem_dirs && !intersect.is_empty ();
238 if (correct_stem_dirs)
240 correction = abs (intersect.length ());
245 correction = min (correction / 7, 1.0);
246 correction *= stem_dirs[LEFT];
248 *= robust_scm2double (me->get_property ("stem-spacing-correction"), 0);
251 if (!bar_yextent.is_empty ())
255 else if (correct_stem_dirs && stem_dirs[LEFT] * stem_dirs[RIGHT] == UP)
258 Correct for the following situation:
267 ^ move the center one to the left.
270 this effect seems to be much more subtle than the
271 stem-direction stuff (why?), and also does not scale with the
272 difference in stem length.
276 Interval hp = head_posns[LEFT];
277 hp.intersect (head_posns[RIGHT]);
282 = (head_posns[LEFT][DOWN] > head_posns[RIGHT][UP]) ? RIGHT : LEFT;
284 Real delta = head_posns[-lowest][DOWN] - head_posns[lowest][UP];
285 Real corr = robust_scm2double (me->get_property ("same-direction-correction"), 0);
288 correction = -lowest * corr;
291 *space += correction;
293 /* there used to be a correction for bar_xextent () here, but
294 it's unclear what that was good for ?
298 ADD_INTERFACE (Note_spacing,
299 "This object calculates spacing wishes for individual voices.",
302 "knee-spacing-correction "
305 "same-direction-correction "
306 "stem-spacing-correction "