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 (min_dist, left_head_end + min_dist/2);
72 We don't do complicated stuff: (base_space - increment) is the
73 normal amount of white, which also determines the amount of
74 stretch. Upon (extreme) stretching, notes with accidentals should
75 stretch as much as notes without accidentals.
77 *space = (base_space - increment) + *fixed;
79 stem_dir_correction (me, right_col, increment, space, fixed);
84 Correct for optical illusions. See [Wanske] p. 138. The combination
85 up-stem + down-stem should get extra space, the combination
86 down-stem + up-stem less.
88 TODO: have to check wether the stems are in the same staff.
91 Note_spacing::stem_dir_correction (Grob *me, Item *rcolumn,
93 Real *space, Real *fixed)
95 Drul_array<Direction> stem_dirs (CENTER, CENTER);
96 Drul_array<Interval> stem_posns;
97 Drul_array<Interval> head_posns;
98 Drul_array<SCM> props (me->get_object ("left-items"),
99 me->get_object ("right-items"));
101 Drul_array<Spanner *> beams_drul (0, 0);
102 Drul_array<Grob *> stems_drul (0, 0);
104 stem_dirs[LEFT] = stem_dirs[RIGHT] = CENTER;
106 Interval bar_xextent;
107 Interval bar_yextent;
109 bool correct_stem_dirs = true;
111 bool acc_right = false;
115 vector<Grob*> const &items (ly_scm2link_array (props [d]));
116 for (vsize i = 0; i < items.size (); i++)
118 Item *it = dynamic_cast<Item *> (items[i]);
121 acc_right = acc_right || Note_column::accidentals (it);
123 Grob *stem = Note_column::get_stem (it);
125 if (!stem || !stem->is_live ())
127 if (d == RIGHT && Separation_item::has_interface (it))
129 if (it->get_column () != rcolumn)
130 it = it->find_prebroken_piece (rcolumn->break_status_dir ());
132 Grob *last = Separation_item::extremal_break_aligned_grob (it, LEFT, &bar_xextent);
135 bar_yextent = Staff_spacing::bar_y_positions (last);
143 if (Stem::is_invisible (stem))
145 correct_stem_dirs = false;
149 stems_drul[d] = stem;
150 beams_drul[d] = Stem::get_beam (stem);
152 Direction stem_dir = get_grob_direction (stem);
153 if (stem_dirs[d] && stem_dirs[d] != stem_dir)
155 correct_stem_dirs = false;
158 stem_dirs[d] = stem_dir;
161 Correction doesn't seem appropriate when there is a large flag
162 hanging from the note.
165 && Stem::duration_log (stem) > 2 && !Stem::get_beam (stem))
166 correct_stem_dirs = false;
168 Interval hp = Stem::head_positions (stem);
169 if (correct_stem_dirs
172 Real chord_start = hp[stem_dir];
175 can't look at stem-end-position, since that triggers
176 beam slope computations.
178 Real stem_end = hp[stem_dir] +
179 stem_dir * robust_scm2double (stem->get_property ("length"), 7);
181 stem_posns[d] = Interval (min (chord_start, stem_end),
182 max (chord_start, stem_end));
183 head_posns[d].unite (hp);
187 while (flip (&d) != LEFT);
190 don't correct if accidentals are sticking out of the right side.
195 Real correction = 0.0;
197 if (!bar_yextent.is_empty ())
199 stem_dirs[RIGHT] = -stem_dirs[LEFT];
200 stem_posns[RIGHT] = bar_yextent;
201 stem_posns[RIGHT] *= 2;
204 if (correct_stem_dirs && stem_dirs[LEFT] * stem_dirs[RIGHT] == -1)
206 if (beams_drul[LEFT] && beams_drul[LEFT] == beams_drul[RIGHT])
210 this is a knee: maximal correction.
212 Real note_head_width = increment;
213 Grob *st = stems_drul[RIGHT];
214 Grob *head = st ? Stem::support_head (st) : 0;
216 Interval head_extent;
219 head_extent = head->extent (rcolumn, X_AXIS);
221 if (!head_extent.is_empty ())
222 note_head_width = head_extent[RIGHT];
224 note_head_width -= Stem::thickness (st);
227 correction = note_head_width * stem_dirs[LEFT];
228 correction *= robust_scm2double (me->get_property ("knee-spacing-correction"), 0);
229 *fixed += correction;
233 intersect = stem_posns[LEFT];
234 intersect.intersect (stem_posns[RIGHT]);
235 correct_stem_dirs = correct_stem_dirs && !intersect.is_empty ();
237 if (correct_stem_dirs)
239 correction = abs (intersect.length ());
244 correction = min (correction / 7, 1.0);
245 correction *= stem_dirs[LEFT];
247 *= robust_scm2double (me->get_property ("stem-spacing-correction"), 0);
250 if (!bar_yextent.is_empty ())
254 else if (correct_stem_dirs && stem_dirs[LEFT] * stem_dirs[RIGHT] == UP)
257 Correct for the following situation:
266 ^ move the center one to the left.
269 this effect seems to be much more subtle than the
270 stem-direction stuff (why?), and also does not scale with the
271 difference in stem length.
275 Interval hp = head_posns[LEFT];
276 hp.intersect (head_posns[RIGHT]);
281 = (head_posns[LEFT][DOWN] > head_posns[RIGHT][UP]) ? RIGHT : LEFT;
283 Real delta = head_posns[-lowest][DOWN] - head_posns[lowest][UP];
284 Real corr = robust_scm2double (me->get_property ("same-direction-correction"), 0);
287 correction = -lowest * corr;
290 *space += correction;
292 /* there used to be a correction for bar_xextent () here, but
293 it's unclear what that was good for ?
297 ADD_INTERFACE (Note_spacing,
298 "This object calculates spacing wishes for individual voices.",
301 "knee-spacing-correction "
304 "same-direction-correction "
305 "stem-spacing-correction "