]> git.donarmstrong.com Git - lilypond.git/blob - lily/slur-scoring.cc
* lily/slur-scoring.cc (get_base_attachments): robustness. Don't
[lilypond.git] / lily / slur-scoring.cc
1 /*
2   slur-scoring.cc -- Score based slur formatting
3
4   source file of the GNU LilyPond music typesetter
5
6   (c) 1996--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
7   Jan Nieuwenhuizen <janneke@gnu.org>
8 */
9
10 #include <math.h>
11
12 #include "slur-scoring.hh"
13 #include "libc-extension.hh"
14 #include "slur-configuration.hh"
15 #include "beam.hh"
16 #include "directional-element-interface.hh"
17 #include "group-interface.hh"
18 #include "slur.hh"
19 #include "note-column.hh"
20 #include "output-def.hh"
21 #include "pitch.hh"
22 #include "spanner.hh"
23 #include "staff-symbol-referencer.hh"
24 #include "staff-symbol.hh"
25 #include "stem.hh"
26 #include "warn.hh"
27 #include "paper-column.hh"
28 #include "accidental-interface.hh"
29
30 /*
31   TODO:
32
33   - curve around flag for y coordinate
34
35   - this file is a mess, clean it up
36
37   - short-cut: try a smaller region first.
38
39   - handle non-visible stems better.
40
41   - try to prune number of scoring criteria
42
43   - take encompass-objects more into account when determining
44   slur shape
45
46   - calculate encompass scoring directly after determining slur shape.
47
48   - optimize.
49 */
50 struct Slur_score_state;
51
52 Slur_score_state::Slur_score_state ()
53 {
54   musical_dy_ = 0.0;
55   valid_ = false;
56   edge_has_beams_ = false;
57   has_same_beam_ = false;
58   is_broken_ = false;
59   dir_ = CENTER;
60   slur_ = 0;
61   common_[X_AXIS] = 0;
62   common_[Y_AXIS] = 0;
63 }
64
65 Slur_score_state::~Slur_score_state ()
66 {
67   junk_pointers (configurations_);
68 }
69
70 Real
71 get_detail (SCM alist, SCM sym)
72 {
73   SCM entry = scm_assq (sym, alist);
74   return robust_scm2double (scm_is_pair (entry)
75                             ? scm_cdr (entry)
76                             : SCM_EOL,
77                             0.0);
78 }
79
80 void
81 Slur_score_parameters::fill (Grob *me)
82 {
83   SCM details = me->get_property ("slur-details");
84
85   region_size_
86     = (int) get_detail (details, ly_symbol2scm ("region-size"));
87   head_encompass_penalty_
88     = get_detail (details, ly_symbol2scm ("head-encompass-penalty"));
89   stem_encompass_penalty_
90     = get_detail (details, ly_symbol2scm ("stem-encompass-penalty"));
91   closeness_factor_
92     = get_detail (details, ly_symbol2scm ("closeness-factor"));
93   edge_attraction_factor_
94     = get_detail (details, ly_symbol2scm ("edge-attraction-factor"));
95   same_slope_penalty_
96     = get_detail (details, ly_symbol2scm ("same-slope-penalty"));
97   steeper_slope_factor_
98     = get_detail (details, ly_symbol2scm ("steeper-slope-factor"));
99   non_horizontal_penalty_
100     = get_detail (details, ly_symbol2scm ("non-horizontal-penalty"));
101   max_slope_
102     = get_detail (details, ly_symbol2scm ("max-slope"));
103   max_slope_factor_
104     = get_detail (details, ly_symbol2scm ("max-slope-factor"));
105   free_head_distance_
106     = get_detail (details, ly_symbol2scm ("free-head-distance"));
107   absolute_closeness_measure_
108     = get_detail (details, ly_symbol2scm ("absolute-closeness-measure"));
109   extra_object_collision_
110     = get_detail (details, ly_symbol2scm ("extra-object-collision"));
111   accidental_collision_
112     = get_detail (details, ly_symbol2scm ("accidental-collision"));
113   extra_encompass_free_distance_
114     = get_detail (details, ly_symbol2scm ("extra-encompass-free-distance"));
115   head_slur_distance_factor_
116     = get_detail (details, ly_symbol2scm ("head-slur-distance-factor"));
117   head_slur_distance_max_ratio_
118     = get_detail (details, ly_symbol2scm ("head-slur-distance-max-ratio"));
119   free_slur_distance_
120     = get_detail (details, ly_symbol2scm ("free-slur-distance"));
121   edge_slope_exponent_
122     = get_detail (details, ly_symbol2scm ("edge-slope-exponent"));
123 }
124
125 Real
126 broken_trend_y (Slur_score_state const &state, Direction hdir)
127 {
128   /* A broken slur should maintain the same vertical trend
129      the unbroken slur would have had.  */
130   Real by = 0.0;
131   if (Spanner *mother = dynamic_cast<Spanner *> (state.slur_->original_))
132     {
133       int k = broken_spanner_index (state.slur_);
134       int j = k + hdir;
135       if (j < 0 || j >= mother->broken_intos_.size ())
136         return by;
137
138       Grob *neighbor = mother->broken_intos_[j];
139       Spanner *common_mother
140         = dynamic_cast<Spanner *> (state.common_[Y_AXIS]->original_);
141       int common_k
142         = broken_spanner_index (dynamic_cast<Spanner *> (state.common_[Y_AXIS]));
143       int common_j = common_k + hdir;
144
145       if (common_j < 0 || common_j >= common_mother->broken_intos_.size ())
146         return by;
147
148       Grob *common_next_system = common_mother->broken_intos_[common_j];
149
150       SCM last_point = scm_car (scm_last_pair (neighbor->get_property ("control-points")));
151
152       return scm_to_double (scm_cdr (last_point))
153         + neighbor->relative_coordinate (common_next_system, Y_AXIS);
154     }
155   return by;
156 }
157
158 /*
159   copy slur dir forwards across line break.
160 */
161 void
162 Slur_score_state::set_next_direction ()
163 {
164   if (extremes_[RIGHT].note_column_)
165     return;
166
167   if (Spanner *mother = dynamic_cast<Spanner *> (slur_->original_))
168     {
169       int k = broken_spanner_index (slur_);
170       int j = k + 1;
171       if (j < 0 || j >= mother->broken_intos_.size ())
172         return;
173
174       Grob *neighbor = mother->broken_intos_[j];
175       set_grob_direction (neighbor, dir_);
176     }
177 }
178
179 Encompass_info
180 Slur_score_state::get_encompass_info (Grob *col) const
181 {
182   Grob *stem = unsmob_grob (col->get_property ("stem"));
183   Encompass_info ei;
184
185   if (!stem)
186     {
187       programming_error ("No stem for note column?");
188       ei.x_ = col->relative_coordinate (common_[X_AXIS], X_AXIS);
189       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS],
190                                          Y_AXIS)[dir_];
191       return ei;
192     }
193   Direction stem_dir = get_grob_direction (stem);
194
195   if (Grob *head = Note_column::first_head (col))
196     ei.x_ = head->extent (common_[X_AXIS], X_AXIS).center ();
197   else
198     ei.x_ = col->extent (common_[X_AXIS], X_AXIS).center ();
199
200   Grob *h = Stem::extremal_heads (stem)[Direction (dir_)];
201   if (!h)
202     {
203       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS], Y_AXIS)[dir_];
204       return ei;
205     }
206
207   ei.head_ = h->extent (common_[Y_AXIS], Y_AXIS)[dir_];
208
209   if ((stem_dir == dir_)
210       && !stem->extent (stem, Y_AXIS).is_empty ())
211     {
212       ei.stem_ = stem->extent (common_[Y_AXIS], Y_AXIS)[dir_];
213       if (Grob *b = Stem::get_beam (stem))
214         ei.stem_ += stem_dir * 0.5 * Beam::get_thickness (b);
215
216       Interval x = stem->extent (common_[X_AXIS], X_AXIS);
217       ei.x_ = x.is_empty ()
218         ? stem->relative_coordinate (common_[X_AXIS], X_AXIS)
219         : x.center ();
220     }
221   else
222     ei.stem_ = ei.head_;
223
224   return ei;
225 }
226
227 Drul_array<Bound_info>
228 Slur_score_state::get_bound_info () const
229 {
230   Drul_array<Bound_info> extremes;
231
232   Direction d = LEFT;
233   Direction dir = dir_;
234
235   do
236     {
237       extremes[d].bound_ = slur_->get_bound (d);
238       if (Note_column::has_interface (extremes[d].bound_))
239         {
240           extremes[d].note_column_ = extremes[d].bound_;
241           extremes[d].stem_ = Note_column::get_stem (extremes[d].note_column_);
242           extremes[d].stem_dir_ = get_grob_direction (extremes[d].stem_);
243           extremes[d].stem_extent_[X_AXIS]
244             = extremes[d].stem_->extent (common_[X_AXIS], X_AXIS);
245           extremes[d].stem_extent_[Y_AXIS]
246             = extremes[d].stem_->extent (common_[Y_AXIS], Y_AXIS);
247           extremes[d].slur_head_
248             = Stem::extremal_heads (extremes[d].stem_)[dir];
249           if (!extremes[d].slur_head_
250               && Note_column::has_rests (extremes[d].bound_))
251             {
252               extremes[d].slur_head_ = Note_column::get_rest (extremes[d].bound_);
253             }
254
255           if (extremes[d].slur_head_)
256             extremes[d].slur_head_extent_
257               = extremes[d].slur_head_->extent (common_[X_AXIS], X_AXIS);
258
259           extremes[d].staff_ = Staff_symbol_referencer
260             ::get_staff_symbol (extremes[d].stem_);
261           extremes[d].staff_space_ = Staff_symbol_referencer
262             ::staff_space (extremes[d].stem_);
263         }
264     }
265   while (flip (&d) != LEFT);
266
267   return extremes;
268 }
269
270 void
271 Slur_score_state::fill (Grob *me)
272 {
273   slur_ = dynamic_cast<Spanner *> (me);
274   columns_
275     = extract_grob_array (me, ly_symbol2scm ("note-columns"));
276
277   if (columns_.is_empty ())
278     {
279       me->suicide ();
280       return;
281     }
282
283   staff_space_ = Staff_symbol_referencer::staff_space (me);
284   Real lt = me->get_layout ()->get_dimension (ly_symbol2scm ("linethickness"));
285   thickness_ = robust_scm2double (me->get_property ("thickness"), 1.0) * lt;
286
287   dir_ = get_grob_direction (me);
288   parameters_.fill (me);
289
290   SCM eltlist = me->get_property ("note-columns");
291   SCM extra_list = me->get_property ("encompass-objects");
292   Spanner *sp = dynamic_cast<Spanner *> (me);
293
294   for (int i = X_AXIS; i < NO_AXES; i++)
295     {
296       Axis a = (Axis)i;
297       common_[a] = common_refpoint_of_list (eltlist, me, a);
298       common_[a] = common_refpoint_of_list (extra_list, common_[a], a);
299
300       Direction d = LEFT;
301       do
302         {
303           /*
304             If bound is not in note-columns, we don't want to know about
305             its Y-position
306           */
307           if (a != Y_AXIS)
308             common_[a] = common_[a]->common_refpoint (sp->get_bound (d), a);
309         }
310       while (flip (&d) != LEFT);
311     }
312
313   extremes_ = get_bound_info ();
314   is_broken_ = (!extremes_[LEFT].note_column_
315                 || !extremes_[RIGHT].note_column_);
316
317   has_same_beam_
318     = (extremes_[LEFT].stem_ && extremes_[RIGHT].stem_
319        && Stem::get_beam (extremes_[LEFT].stem_) == Stem::get_beam (extremes_[RIGHT].stem_));
320
321   base_attachments_ = get_base_attachments ();
322
323   Drul_array<Real> end_ys
324     = get_y_attachment_range ();
325
326   configurations_ = enumerate_attachments (end_ys);
327   for (int i = 0; i < columns_.size (); i++)
328     encompass_infos_.push (get_encompass_info (columns_[i]));
329
330   extra_encompass_infos_ = get_extra_encompass_infos ();
331   valid_ = true;
332
333   musical_dy_ = 0.0;
334   Direction d = LEFT;
335   do
336     {
337       if (!is_broken_)
338         musical_dy_ += d
339           * extremes_[d].slur_head_->relative_coordinate (common_[Y_AXIS], Y_AXIS);
340     }
341   while (flip (&d) != LEFT);
342
343   edge_has_beams_
344     = (extremes_[LEFT].stem_ && Stem::get_beam (extremes_[LEFT].stem_))
345     || (extremes_[RIGHT].stem_ && Stem::get_beam (extremes_[RIGHT].stem_));
346
347   set_next_direction ();
348
349   if (is_broken_)
350     musical_dy_ = 0.0;
351 }
352
353 void
354 set_slur_control_points (Grob *me)
355 {
356   Slur_score_state state;
357   state.fill (me);
358
359   if (!state.valid_)
360     return;
361
362   state.generate_curves ();
363
364   SCM end_ys = me->get_property ("positions");
365   Bezier best;
366
367   if (is_number_pair (end_ys))
368     {
369       best = state.configurations_[state.get_closest_index (end_ys)]->curve_;
370     }
371   else
372     {
373       best = state.get_best_curve ();
374     }
375
376   SCM controls = SCM_EOL;
377   for (int i = 4; i--;)
378     {
379       Offset o = best.control_[i]
380         - Offset (me->relative_coordinate (state.common_[X_AXIS], X_AXIS),
381                   me->relative_coordinate (state.common_[Y_AXIS], Y_AXIS));
382       controls = scm_cons (ly_offset2scm (o), controls);
383     }
384   me->set_property ("control-points", controls);
385 }
386
387 Bezier
388 Slur_score_state::get_best_curve ()
389 {
390   for (int i = 0; i < configurations_.size (); i++)
391     {
392       configurations_[i]->score (*this);
393     }
394
395   Real opt = 1e6;
396   int opt_idx = -1;
397   for (int i = 0; i < configurations_.size (); i++)
398     {
399       if (configurations_[i]->score_ < opt)
400         {
401           opt = configurations_[i]->score_;
402           opt_idx = i;
403         }
404     }
405
406 #if DEBUG_SLUR_SCORING
407   SCM inspect_quants = slur_->get_property ("inspect-quants");
408   if (to_boolean (slur_->get_layout ()
409                   ->lookup_variable (ly_symbol2scm ("debug-slur-scoring")))
410       && scm_is_pair (inspect_quants))
411     opt_idx = get_closest_index (inspect_quants);
412
413   configurations_[opt_idx]->score_card_ += to_string ("=%.2f", opt);
414   configurations_[opt_idx]->score_card_ += to_string ("i%d", opt_idx);
415
416   // debug quanting
417   slur_->set_property ("quant-score",
418                        scm_makfrom0str (configurations_[opt_idx]->score_card_.to_str0 ()));
419
420 #endif
421
422   return configurations_[opt_idx]->curve_;
423 }
424
425 int
426 Slur_score_state::get_closest_index (SCM inspect_quants) const
427 {
428   Drul_array<Real> ins = ly_scm2interval (inspect_quants);
429
430   int opt_idx = -1;
431   Real mindist = 1e6;
432   for (int i = 0; i < configurations_.size (); i++)
433     {
434       Real d = fabs (configurations_[i]->attachment_[LEFT][Y_AXIS] - ins[LEFT])
435         + fabs (configurations_[i]->attachment_[RIGHT][Y_AXIS] - ins[RIGHT]);
436       if (d < mindist)
437         {
438           opt_idx = i;
439           mindist = d;
440         }
441     }
442   if (mindist > 1e5)
443     programming_error ("Could not find quant.");
444   return opt_idx;
445 }
446
447 /*
448   TODO: should analyse encompasses to determine sensible region, and
449   should limit slopes available.
450 */
451
452 Drul_array<Real>
453 Slur_score_state::get_y_attachment_range () const
454 {
455   Drul_array<Real> end_ys;
456   Direction d = LEFT;
457   do
458     {
459       if (extremes_[d].note_column_)
460         {
461           end_ys[d] = dir_
462             * ((dir_ * (base_attachments_[d][Y_AXIS] + parameters_.region_size_ * dir_))
463                >? (dir_ * (dir_ + extremes_[d].note_column_->extent (common_[Y_AXIS],
464                                                                      Y_AXIS)[dir_]))
465                >? (dir_ * base_attachments_[-d][Y_AXIS]));
466         }
467       else
468         end_ys[d] = base_attachments_[d][Y_AXIS] + parameters_.region_size_ * dir_;
469     }
470   while (flip (&d) != LEFT);
471
472   return end_ys;
473 }
474
475 bool
476 spanner_less (Spanner *s1, Spanner *s2)
477 {
478   Slice b1, b2;
479   Direction d = LEFT;
480   do
481     {
482       b1[d] = s1->get_bound (d)->get_column ()->rank_;
483       b2[d] = s2->get_bound (d)->get_column ()->rank_;
484     }
485   while (flip (&d) != LEFT);
486
487   return b2[LEFT] <= b1[LEFT] && b2[RIGHT] >= b1[RIGHT]
488     && (b2[LEFT] != b1[LEFT] || b2[RIGHT] != b1[RIGHT]);
489 }
490
491 Drul_array<Offset>
492 Slur_score_state::get_base_attachments () const
493 {
494   Drul_array<Offset> base_attachment;
495   Direction d = LEFT;
496   do
497     {
498       Grob *stem = extremes_[d].stem_;
499       Grob *head = extremes_[d].slur_head_;
500
501       Real x = 0.0;
502       Real y = 0.0;
503       if (extremes_[d].note_column_)
504         {
505
506           /*
507             fixme: X coord should also be set in this case.
508           */
509           if (stem
510               && extremes_[d].stem_dir_ == dir_
511               && Stem::get_beaming (stem, -d)
512               && (!spanner_less (slur_, Stem::get_beam (stem))
513                   || has_same_beam_))
514             y = extremes_[d].stem_extent_[Y_AXIS][dir_];
515           else if (head)
516             y = head->extent (common_[Y_AXIS], Y_AXIS)[dir_];
517           y += dir_ * 0.5 * staff_space_;
518
519           y = move_away_from_staffline (y, head);
520
521           Grob *fh = Note_column::first_head (extremes_[d].note_column_);
522           x
523             = (fh ? fh->extent (common_[X_AXIS], X_AXIS)
524                : extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS))
525             .linear_combination (CENTER);
526         }
527       base_attachment[d] = Offset (x, y);
528     }
529   while (flip (&d) != LEFT);
530
531   do
532     {
533       if (!extremes_[d].note_column_)
534         {
535           Real x, y;
536           if (d == RIGHT)
537             {
538               x = extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS)[d];
539             }
540           else
541             {
542               x = slur_->get_broken_left_end_align ();
543             }
544           Grob *col = (d == LEFT) ? columns_[0] : columns_.top ();
545
546           if (extremes_[-d].bound_ != col)
547             {
548               y = robust_relative_extent (col, common_[Y_AXIS], Y_AXIS)[dir_];
549               y += dir_ * 0.5 * staff_space_;
550
551               if (get_grob_direction (col) == dir_
552                   && Note_column::get_stem (col)
553                   && !Stem::is_invisible (Note_column::get_stem (col)))
554                 y -= dir_ * 1.5 * staff_space_;
555             }
556           else
557             y = base_attachment[-d][Y_AXIS];
558
559           y = move_away_from_staffline (y, col);
560
561           base_attachment[d] = Offset (x, y);
562         }
563     }
564   while (flip (&d) != LEFT);
565
566
567   do
568     {
569       for (int a = X_AXIS; a < NO_AXES; a++)
570         {
571           Real &b = base_attachment[d][Axis (a)];
572
573           if (isinf (b) || isnan (b))
574             {
575               b = 0.0;
576               programming_error ("Slur attachment is inf/nan");
577             }
578             
579         }
580     }
581   while (flip (&d) != LEFT);
582   
583   
584   return base_attachment;
585 }
586
587 Real
588 Slur_score_state::move_away_from_staffline (Real y,
589                                             Grob *on_staff) const
590 {
591   Real pos
592     = (y - Staff_symbol_referencer::get_staff_symbol (on_staff)->relative_coordinate (common_[Y_AXIS],
593                                                                                       Y_AXIS))
594     * 2.0 / staff_space_;
595
596   if (fabs (pos - my_round (pos)) < 0.2
597       && Staff_symbol_referencer::on_staffline (on_staff, (int) rint (pos))
598       && Staff_symbol_referencer::line_count (on_staff) - 1 >= rint (pos))
599     y += 1.5 * staff_space_ * dir_ / 10;
600
601   return y;
602 }
603
604 void
605 Slur_score_state::generate_curves () const
606 {
607   Real r_0 = robust_scm2double (slur_->get_property ("ratio"), 0.33);
608   Real h_inf = staff_space_ * scm_to_double (slur_->get_property ("height-limit"));
609   for (int i = 0; i < configurations_.size (); i++)
610     configurations_[i]->generate_curve (*this, r_0, h_inf);
611 }
612
613 Link_array<Slur_configuration>
614 Slur_score_state::enumerate_attachments (Drul_array<Real> end_ys) const
615 {
616   /*ugh.   */
617   Link_array<Slur_configuration> scores;
618
619   Drul_array<Offset> os;
620   os[LEFT] = base_attachments_[LEFT];
621   Real minimum_length = staff_space_
622     * robust_scm2double (slur_->get_property ("minimum-length"), 2.0);
623
624   for (int i = 0; dir_ * os[LEFT][Y_AXIS] <= dir_ * end_ys[LEFT]; i++)
625     {
626       os[RIGHT] = base_attachments_[RIGHT];
627       for (int j = 0; dir_ * os[RIGHT][Y_AXIS] <= dir_ * end_ys[RIGHT]; j++)
628         {
629           Slur_configuration s;
630           Direction d = LEFT;
631           Drul_array<bool> attach_to_stem (false, false);
632           do
633             {
634               os[d][X_AXIS] = base_attachments_[d][X_AXIS];
635               if (extremes_[d].stem_
636                   && !Stem::is_invisible (extremes_[d].stem_)
637                   && extremes_[d].stem_dir_ == dir_)
638                 {
639                   Interval stem_y = extremes_[d].stem_extent_[Y_AXIS];
640                   stem_y.widen (0.25 * staff_space_);
641                   if (stem_y.contains (os[d][Y_AXIS]))
642                     {
643                       os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS][-d]
644                         - d * 0.3;
645                       attach_to_stem[d] = true;
646                     }
647                   else if (dir_ * extremes_[d].stem_extent_[Y_AXIS][dir_]
648                            < dir_ * os[d][Y_AXIS]
649                            && !extremes_[d].stem_extent_[X_AXIS].is_empty ())
650
651                     os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS].center ();
652                 }
653             }
654           while (flip (&d) != LEFT);
655
656           Offset dz;
657           dz = os[RIGHT] - os[LEFT];
658           if (dz[X_AXIS] < minimum_length
659               || fabs (dz[Y_AXIS] / dz[X_AXIS]) > parameters_.max_slope_)
660             {
661               do
662                 {
663                   if (extremes_[d].slur_head_)
664                     {
665                       os[d][X_AXIS] = extremes_[d].slur_head_extent_.center ();
666                       attach_to_stem[d] = false;
667                     }
668                 }
669               while (flip (&d) != LEFT);
670             }
671
672           dz = os[RIGHT] - os[LEFT];
673           do
674             {
675               if (extremes_[d].slur_head_
676                   && !attach_to_stem[d])
677                 {
678                   /* Horizontally move tilted slurs a little.  Move
679                      more for bigger tilts.
680
681                      TODO: parameter */
682                   os[d][X_AXIS]
683                     -= dir_ * extremes_[d].slur_head_extent_.length ()
684                     * sin (dz.arg ()) / 3;
685                 }
686             }
687           while (flip (&d) != LEFT);
688
689           s.attachment_ = os;
690           s.index_ = scores.size ();
691
692           scores.push (new Slur_configuration (s));
693
694           os[RIGHT][Y_AXIS] += dir_ * staff_space_ / 2;
695         }
696
697       os[LEFT][Y_AXIS] += dir_ * staff_space_ / 2;
698     }
699
700   assert (scores.size () > 0);
701   return scores;
702 }
703
704 Array<Extra_collision_info>
705 Slur_score_state::get_extra_encompass_infos () const
706 {
707   Link_array<Grob> encompasses
708     = extract_grob_array (slur_, ly_symbol2scm ("encompass-objects"));
709   Array<Extra_collision_info> collision_infos;
710   for (int i = encompasses.size (); i--;)
711     {
712       if (Slur::has_interface (encompasses[i]))
713         {
714           Spanner *small_slur = dynamic_cast<Spanner *> (encompasses[i]);
715           Bezier b = Slur::get_curve (small_slur);
716
717           Offset relative (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
718                            small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
719
720           for (int k = 0; k < 3; k++)
721             {
722               Direction hdir = Direction (k / 2 - 1);
723
724               /*
725                 Only take bound into account if small slur starts
726                 together with big slur.
727               */
728               if (hdir && small_slur->get_bound (hdir) != slur_->get_bound (hdir))
729                 continue;
730
731               Offset z = b.curve_point (k / 2.0);
732               z += relative;
733
734               Interval yext;
735               yext.set_full ();
736               yext[dir_] = z[Y_AXIS] + dir_ * thickness_ * 1.0;
737
738               Interval xext (-1, 1);
739               xext = xext * (thickness_ * 2) + z[X_AXIS];
740               Extra_collision_info info (small_slur,
741                                          k - 1.0,
742                                          xext,
743                                          yext,
744                                          parameters_.extra_object_collision_);
745               collision_infos.push (info);
746             }
747         }
748       else
749         {
750           Grob *g = encompasses [i];
751           Interval xe = g->extent (common_[X_AXIS], X_AXIS);
752           Interval ye = g->extent (common_[Y_AXIS], Y_AXIS);
753
754           Real xp = 0.0;
755           Real penalty = parameters_.extra_object_collision_;
756           if (Accidental_interface::has_interface (g))
757             {
758               penalty = parameters_.accidental_collision_;
759               /* Begin copy accidental.cc */
760               bool parens = false;
761               if (to_boolean (g->get_property ("cautionary")))
762                 {
763                   SCM cstyle = g->get_property ("cautionary-style");
764                   parens = ly_c_equal_p (cstyle, ly_symbol2scm ("parentheses"));
765                 }
766
767               SCM accs = g->get_property ("accidentals");
768               SCM scm_style = g->get_property ("style");
769               if (!scm_is_symbol (scm_style)
770                   && !parens
771                   && scm_ilength (accs) == 1)
772                 {
773                   /* End copy accidental.cc */
774                   switch (scm_to_int (scm_car (accs)))
775                     {
776                     case FLAT:
777                     case DOUBLE_FLAT:
778                       xp = LEFT;
779                       break;
780                     case SHARP:
781                       xp = 0.5 * dir_;
782                       break;
783                     case NATURAL:
784                       xp = -dir_;
785                       break;
786                     }
787                 }
788             }
789
790           ye.widen (thickness_ * 0.5);
791           xe.widen (thickness_ * 1.0);
792           Extra_collision_info info (g, xp, xe, ye, penalty);
793           collision_infos.push (info);
794         }
795     }
796
797   return collision_infos;
798 }
799