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1 /*
2   This file is part of LilyPond, the GNU music typesetter.
3
4   Copyright (C) 1996--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
5   Jan Nieuwenhuizen <janneke@gnu.org>
6
7   LilyPond is free software: you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation, either version 3 of the License, or
10   (at your option) any later version.
11
12   LilyPond is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include "slur-scoring.hh"
22
23 #include <queue>
24
25 #include "axis-group-interface.hh"
26 #include "accidental-interface.hh"
27 #include "beam.hh"
28 #include "clef.hh"
29 #include "directional-element-interface.hh"
30 #include "dots.hh"
31 #include "libc-extension.hh"
32 #include "main.hh"
33 #include "misc.hh"
34 #include "note-column.hh"
35 #include "output-def.hh"
36 #include "paper-column.hh"
37 #include "pitch.hh"
38 #include "pointer-group-interface.hh"
39 #include "slur-configuration.hh"
40 #include "slur.hh"
41 #include "spanner.hh"
42 #include "staff-symbol-referencer.hh"
43 #include "staff-symbol.hh"
44 #include "stem.hh"
45 #include "time-signature.hh"
46 #include "warn.hh"
47
48 /*
49   TODO:
50
51   - curve around flag for y coordinate
52
53   - short-cut: try a smaller region first.
54
55   - handle non-visible stems better.
56
57   - try to prune number of scoring criteria
58
59   - take encompass-objects more into account when determining
60   slur shape
61
62   - calculate encompass scoring directly after determining slur shape.
63
64   - optimize.
65 */
66 struct Slur_score_state;
67
68 Slur_score_state::Slur_score_state ()
69 {
70   musical_dy_ = 0.0;
71   valid_ = false;
72   edge_has_beams_ = false;
73   has_same_beam_ = false;
74   is_broken_ = false;
75   dir_ = CENTER;
76   slur_ = 0;
77   common_[X_AXIS] = 0;
78   common_[Y_AXIS] = 0;
79 }
80
81 Slur_score_state::~Slur_score_state ()
82 {
83   junk_pointers (configurations_);
84 }
85
86 /*
87   If a slur is broken across a line break, the direction
88   of the post-break slur must be the same as the pre-break
89   slur.
90 */
91 Direction
92 Slur_score_state::slur_direction () const
93 {
94   Grob *left_neighbor = slur_->broken_neighbor (LEFT);
95
96   if (left_neighbor && left_neighbor->is_live ())
97     return get_grob_direction (left_neighbor);
98
99   Direction dir = get_grob_direction (slur_);
100
101   if (Grob *right_neighbor = slur_->broken_neighbor (RIGHT))
102     set_grob_direction (right_neighbor, dir);
103
104   return dir;
105 }
106
107 Encompass_info
108 Slur_score_state::get_encompass_info (Grob *col) const
109 {
110   Grob *stem = unsmob_grob (col->get_object ("stem"));
111   Encompass_info ei;
112
113   if (!stem)
114     {
115       programming_error ("no stem for note column");
116       ei.x_ = col->relative_coordinate (common_[X_AXIS], X_AXIS);
117       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS],
118                                          Y_AXIS)[dir_];
119       return ei;
120     }
121   Direction stem_dir = get_grob_direction (stem);
122
123   if (Grob *head = Note_column::first_head (col))
124     ei.x_ = head->extent (common_[X_AXIS], X_AXIS).center ();
125   else
126     ei.x_ = col->extent (common_[X_AXIS], X_AXIS).center ();
127
128   Grob *h = Stem::extremal_heads (stem)[Direction (dir_)];
129   if (!h)
130     {
131       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS], Y_AXIS)[dir_];
132       return ei;
133     }
134
135   ei.head_ = h->extent (common_[Y_AXIS], Y_AXIS)[dir_];
136
137   if ((stem_dir == dir_)
138       && !stem->extent (stem, Y_AXIS).is_empty ())
139     {
140       ei.stem_ = stem->extent (common_[Y_AXIS], Y_AXIS)[dir_];
141       if (Grob *b = Stem::get_beam (stem))
142         ei.stem_ += stem_dir * 0.5 * Beam::get_beam_thickness (b);
143
144       Interval x = stem->extent (common_[X_AXIS], X_AXIS);
145       ei.x_ = x.is_empty ()
146               ? stem->relative_coordinate (common_[X_AXIS], X_AXIS)
147               : x.center ();
148     }
149   else
150     ei.stem_ = ei.head_;
151
152   return ei;
153 }
154
155 Drul_array<Bound_info>
156 Slur_score_state::get_bound_info () const
157 {
158   Drul_array<Bound_info> extremes;
159
160   Direction dir = dir_;
161
162   for (LEFT_and_RIGHT (d))
163     {
164       extremes[d].bound_ = slur_->get_bound (d);
165       if (Note_column::has_interface (extremes[d].bound_))
166         {
167           extremes[d].note_column_ = extremes[d].bound_;
168           extremes[d].stem_ = Note_column::get_stem (extremes[d].note_column_);
169           extremes[d].flag_ = Note_column::get_flag (extremes[d].note_column_);
170
171           if (extremes[d].stem_)
172             {
173               extremes[d].stem_dir_ = get_grob_direction (extremes[d].stem_);
174
175               for (int a = X_AXIS; a < NO_AXES; a++)
176                 {
177                   Axis ax = Axis (a);
178                   Interval s = extremes[d].stem_->extent (common_[ax], ax);
179                   if (extremes[d].flag_)
180                     s.unite (extremes[d].flag_->extent (common_[ax], ax));
181                   if (s.is_empty ())
182                     {
183                       /*
184                         do not issue warning. This happens for rests and
185                         whole notes.
186                       */
187                       s = Interval (0, 0)
188                           + extremes[d].stem_->relative_coordinate (common_[ax], ax);
189                     }
190                   extremes[d].stem_extent_[ax] = s;
191                 }
192
193               extremes[d].slur_head_
194                 = Stem::extremal_heads (extremes[d].stem_)[dir];
195               if (!extremes[d].slur_head_
196                   && Note_column::has_rests (extremes[d].bound_))
197                 extremes[d].slur_head_ = Note_column::get_rest (extremes[d].bound_);
198               extremes[d].staff_ = Staff_symbol_referencer
199                                    ::get_staff_symbol (extremes[d].stem_);
200               extremes[d].staff_space_ = Staff_symbol_referencer
201                                          ::staff_space (extremes[d].stem_);
202             }
203
204           if (extremes[d].slur_head_)
205             extremes[d].slur_head_x_extent_
206               = extremes[d].slur_head_->extent (common_[X_AXIS], X_AXIS);
207
208         }
209     }
210
211   return extremes;
212 }
213
214 void
215 Slur_score_state::fill (Grob *me)
216 {
217   slur_ = dynamic_cast<Spanner *> (me);
218   columns_
219     = internal_extract_grob_array (me, ly_symbol2scm ("note-columns"));
220
221   if (columns_.empty ())
222     {
223       me->suicide ();
224       return;
225     }
226
227   Slur::replace_breakable_encompass_objects (me);
228   staff_space_ = Staff_symbol_referencer::staff_space (me);
229   line_thickness_ = me->layout ()->get_dimension (ly_symbol2scm ("line-thickness"));
230   thickness_ = robust_scm2double (me->get_property ("thickness"), 1.0) * line_thickness_;
231
232   dir_ = slur_direction ();
233   parameters_.fill (me);
234
235   extract_grob_set (me, "note-columns", columns);
236   extract_grob_set (me, "encompass-objects", extra_objects);
237
238   Spanner *sp = dynamic_cast<Spanner *> (me);
239
240   for (int i = X_AXIS; i < NO_AXES; i++)
241     {
242       Axis a = (Axis)i;
243       common_[a] = common_refpoint_of_array (columns, me, a);
244       common_[a] = common_refpoint_of_array (extra_objects, common_[a], a);
245
246       for (LEFT_and_RIGHT (d))
247         {
248           /*
249             If bound is not in note-columns, we don't want to know about
250             its Y-position
251           */
252           if (a != Y_AXIS)
253             common_[a] = common_[a]->common_refpoint (sp->get_bound (d), a);
254         }
255     }
256
257   extremes_ = get_bound_info ();
258   is_broken_ = (!extremes_[LEFT].note_column_
259                 || !extremes_[RIGHT].note_column_);
260
261   has_same_beam_
262     = (extremes_[LEFT].stem_ && extremes_[RIGHT].stem_
263        && Stem::get_beam (extremes_[LEFT].stem_) == Stem::get_beam (extremes_[RIGHT].stem_));
264
265   base_attachments_ = get_base_attachments ();
266
267   Drul_array<Real> end_ys
268     = get_y_attachment_range ();
269
270   extra_encompass_infos_ = get_extra_encompass_infos ();
271
272   Interval additional_ys (0.0, 0.0);
273
274   for (vsize i = 0; i < extra_encompass_infos_.size (); i++)
275     {
276       if (extra_encompass_infos_[i].extents_[X_AXIS].is_empty ())
277         continue;
278
279       Real y_place = linear_interpolate (extra_encompass_infos_[i].extents_[X_AXIS].center (),
280                                          base_attachments_[RIGHT][X_AXIS],
281                                          base_attachments_[LEFT][X_AXIS],
282                                          end_ys[RIGHT],
283                                          end_ys[LEFT]);
284       Real encompass_place = extra_encompass_infos_[i].extents_[Y_AXIS][dir_];
285       if (extra_encompass_infos_[i].type_ == ly_symbol2scm ("inside")
286           && minmax (dir_, encompass_place, y_place) == encompass_place
287           && (!extra_encompass_infos_[i].grob_->internal_has_interface (ly_symbol2scm ("key-signature-interface"))
288               && !Clef::has_interface (extra_encompass_infos_[i].grob_)
289               && !Time_signature::has_interface (extra_encompass_infos_[i].grob_)))
290         {
291           for (LEFT_and_RIGHT (d))
292             additional_ys[d] = minmax (dir_,
293                                        additional_ys[d],
294                                        (dir_
295                                         * (parameters_.encompass_object_range_overshoot_
296                                            + (y_place - encompass_place)
297                                            * (normalize (extra_encompass_infos_[i].extents_[X_AXIS].center (),
298                                                          base_attachments_[RIGHT][X_AXIS],
299                                                          base_attachments_[LEFT][X_AXIS])
300                                               + (dir_ == LEFT ? 0 : -1)))));
301         }
302     }
303
304   for (LEFT_and_RIGHT (d))
305     end_ys[d] += additional_ys[d];
306
307   configurations_ = enumerate_attachments (end_ys);
308   for (vsize i = 0; i < columns_.size (); i++)
309     encompass_infos_.push_back (get_encompass_info (columns_[i]));
310
311   valid_ = true;
312
313   musical_dy_ = 0.0;
314   for (LEFT_and_RIGHT (d))
315     {
316       if (!is_broken_
317           && extremes_[d].slur_head_)
318         musical_dy_ += d
319                        * extremes_[d].slur_head_->relative_coordinate (common_[Y_AXIS], Y_AXIS);
320     }
321
322   edge_has_beams_
323     = (extremes_[LEFT].stem_ && Stem::get_beam (extremes_[LEFT].stem_))
324       || (extremes_[RIGHT].stem_ && Stem::get_beam (extremes_[RIGHT].stem_));
325
326   if (is_broken_)
327     musical_dy_ = 0.0;
328 }
329
330 MAKE_SCHEME_CALLBACK (Slur, calc_control_points, 1)
331 SCM
332 Slur::calc_control_points (SCM smob)
333 {
334   Spanner *me = unsmob_spanner (smob);
335
336   Slur_score_state state;
337   state.fill (me);
338
339   if (!state.valid_)
340     return SCM_EOL;
341
342   state.generate_curves ();
343
344   SCM end_ys = me->get_property ("positions");
345   SCM inspect_quants = me->get_property ("inspect-quants");
346   bool debug_slurs = to_boolean (me->layout ()
347                                  ->lookup_variable (ly_symbol2scm ("debug-slur-scoring")));
348
349   if (is_number_pair (inspect_quants))
350     {
351       debug_slurs = true;
352       end_ys = inspect_quants;
353     }
354
355   Slur_configuration *best = NULL;
356   if (is_number_pair (end_ys))
357     best = state.get_forced_configuration (ly_scm2interval (end_ys));
358   else
359     best = state.get_best_curve ();
360
361 #if DEBUG_SLUR_SCORING
362   if (debug_slurs)
363     {
364       string total = best->card ();
365       total += to_string (" TOTAL=%.2f idx=%d", best->score (), best->index_);
366       me->set_property ("annotation", ly_string2scm (total));
367     }
368 #endif
369
370   SCM controls = SCM_EOL;
371   for (int i = 4; i--;)
372     {
373       Offset o = best->curve_.control_[i]
374                  - Offset (me->relative_coordinate (state.common_[X_AXIS], X_AXIS),
375                            me->relative_coordinate (state.common_[Y_AXIS], Y_AXIS));
376       controls = scm_cons (ly_offset2scm (o), controls);
377     }
378
379   return controls;
380 }
381
382 Slur_configuration *
383 Slur_score_state::get_forced_configuration (Interval ys) const
384 {
385   Slur_configuration *best = NULL;
386   Real mindist = 1e6;
387   for (vsize i = 0; i < configurations_.size (); i++)
388     {
389       Real d = fabs (configurations_[i]->attachment_[LEFT][Y_AXIS] - ys[LEFT])
390                + fabs (configurations_[i]->attachment_[RIGHT][Y_AXIS] - ys[RIGHT]);
391       if (d < mindist)
392         {
393           best = configurations_[i];
394           mindist = d;
395         }
396     }
397
398   while (!best->done ())
399     best->run_next_scorer (*this);
400
401   if (mindist > 1e5)
402     programming_error ("cannot find quant");
403
404   return best;
405 }
406
407 Slur_configuration *
408 Slur_score_state::get_best_curve () const
409 {
410   std::priority_queue < Slur_configuration *, std::vector<Slur_configuration *>,
411       Slur_configuration_less > queue;
412   for (vsize i = 0; i < configurations_.size (); i++)
413     queue.push (configurations_[i]);
414
415   Slur_configuration *best = NULL;
416   while (true)
417     {
418       best = queue.top ();
419       if (best->done ())
420         break;
421
422       queue.pop ();
423       best->run_next_scorer (*this);
424       queue.push (best);
425     }
426
427   return best;
428 }
429
430 Interval
431 Slur_score_state::breakable_bound_extent (Direction d) const
432 {
433   Grob *col = slur_->get_bound (d)->get_column ();
434   Interval ret;
435   ret.set_empty ();
436
437   extract_grob_set (slur_, "encompass-objects", extra_encompasses);
438
439   for (vsize i = 0; i < extra_encompasses.size (); i++)
440     {
441       Item *item = dynamic_cast<Item *> (extra_encompasses[i]);
442       if (item && col == item->get_column ())
443         ret.unite (robust_relative_extent (item, common_[X_AXIS], X_AXIS));
444     }
445
446   return ret;
447 }
448
449 /*
450   TODO: should analyse encompasses to determine sensible region, and
451   should limit slopes available.
452 */
453
454 Drul_array<Real>
455 Slur_score_state::get_y_attachment_range () const
456 {
457   Drul_array<Real> end_ys;
458   for (LEFT_and_RIGHT (d))
459     {
460       if (extremes_[d].note_column_)
461         {
462           Interval nc_extent = extremes_[d].note_column_
463                                ->extent (common_[Y_AXIS], Y_AXIS);
464           if (nc_extent.is_empty ())
465             slur_->warning ("slur trying to encompass an empty note column.");
466           else
467             end_ys[d] = dir_
468                         * max (max (dir_ * (base_attachments_[d][Y_AXIS]
469                                             + parameters_.region_size_ * dir_),
470                                     dir_ * (dir_ + nc_extent[dir_])),
471                                dir_ * base_attachments_[-d][Y_AXIS]);
472         }
473       else
474         end_ys[d] = base_attachments_[d][Y_AXIS] + parameters_.region_size_ * dir_;
475     }
476
477   return end_ys;
478 }
479
480 bool
481 spanner_less (Spanner *s1, Spanner *s2)
482 {
483   Slice b1, b2;
484   for (LEFT_and_RIGHT (d))
485     {
486       b1[d] = s1->get_bound (d)->get_column ()->get_rank ();
487       b2[d] = s2->get_bound (d)->get_column ()->get_rank ();
488     }
489
490   return b2[LEFT] <= b1[LEFT] && b2[RIGHT] >= b1[RIGHT]
491          && (b2[LEFT] != b1[LEFT] || b2[RIGHT] != b1[RIGHT]);
492 }
493
494 Drul_array<Offset>
495 Slur_score_state::get_base_attachments () const
496 {
497   Drul_array<Offset> base_attachment;
498   for (LEFT_and_RIGHT (d))
499     {
500       Grob *stem = extremes_[d].stem_;
501       Grob *head = extremes_[d].slur_head_;
502
503       Real x = 0.0;
504       Real y = 0.0;
505       if (extremes_[d].note_column_)
506         {
507
508           /*
509             fixme: X coord should also be set in this case.
510           */
511           if (stem
512               && !Stem::is_invisible (stem)
513               && extremes_[d].stem_dir_ == dir_
514               && Stem::get_beaming (stem, -d)
515               && Stem::get_beam (stem)
516               && (!spanner_less (slur_, Stem::get_beam (stem))
517                   || has_same_beam_))
518             y = extremes_[d].stem_extent_[Y_AXIS][dir_];
519           else if (head)
520             y = head->extent (common_[Y_AXIS], Y_AXIS)[dir_];
521           y += dir_ * 0.5 * staff_space_;
522
523           y = move_away_from_staffline (y, head);
524
525           Grob *fh = Note_column::first_head (extremes_[d].note_column_);
526           x
527             = (fh ? fh->extent (common_[X_AXIS], X_AXIS)
528                : extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS))
529               .linear_combination (CENTER);
530         }
531       base_attachment[d] = Offset (x, y);
532     }
533
534   for (LEFT_and_RIGHT (d))
535     {
536       if (!extremes_[d].note_column_)
537         {
538           Real x = 0;
539           Real y = 0;
540
541           Interval ext = breakable_bound_extent (d);
542           if (ext.is_empty ())
543             ext = Axis_group_interface::
544                   generic_bound_extent (extremes_[d].bound_,
545                                         common_[X_AXIS], X_AXIS);
546           x = ext[-d];
547
548           Grob *col = (d == LEFT) ? columns_[0] : columns_.back ();
549
550           if (extremes_[-d].bound_ != col)
551             {
552               y = robust_relative_extent (col, common_[Y_AXIS], Y_AXIS)[dir_];
553               y += dir_ * 0.5 * staff_space_;
554
555               if (get_grob_direction (col) == dir_
556                   && Note_column::get_stem (col)
557                   && !Stem::is_invisible (Note_column::get_stem (col)))
558                 y -= dir_ * 1.5 * staff_space_;
559             }
560           else
561             y = base_attachment[-d][Y_AXIS];
562
563           y = move_away_from_staffline (y, col);
564
565           base_attachment[d] = Offset (x, y);
566         }
567     }
568
569   for (LEFT_and_RIGHT (d))
570     {
571       for (int a = X_AXIS; a < NO_AXES; a++)
572         {
573           Real &b = base_attachment[d][Axis (a)];
574
575           if (isinf (b) || isnan (b))
576             {
577               programming_error ("slur attachment is inf/nan");
578               b = 0.0;
579             }
580         }
581     }
582
583   return base_attachment;
584 }
585
586 Real
587 Slur_score_state::move_away_from_staffline (Real y,
588                                             Grob *on_staff) const
589 {
590   if (!on_staff)
591     return y;
592
593   Grob *staff_symbol = Staff_symbol_referencer::get_staff_symbol (on_staff);
594   if (!staff_symbol)
595     return y;
596
597   Real pos
598     = (y - staff_symbol->relative_coordinate (common_[Y_AXIS],
599                                               Y_AXIS))
600       * 2.0 / staff_space_;
601
602   if (fabs (pos - my_round (pos)) < 0.2
603       && Staff_symbol_referencer::on_staff_line (on_staff, (int) rint (pos)))
604     y += 1.5 * staff_space_ * dir_ / 10;
605
606   return y;
607 }
608
609 vector<Offset>
610 Slur_score_state::generate_avoid_offsets () const
611 {
612   vector<Offset> avoid;
613   vector<Grob *> encompasses = columns_;
614
615   for (vsize i = 0; i < encompasses.size (); i++)
616     {
617       if (extremes_[LEFT].note_column_ == encompasses[i]
618           || extremes_[RIGHT].note_column_ == encompasses[i])
619         continue;
620
621       Encompass_info inf (get_encompass_info (encompasses[i]));
622       Real y = dir_ * (max (dir_ * inf.head_, dir_ * inf.stem_));
623
624       avoid.push_back (Offset (inf.x_, y + dir_ * parameters_.free_head_distance_));
625     }
626
627   extract_grob_set (slur_, "encompass-objects", extra_encompasses);
628   for (vsize i = 0; i < extra_encompasses.size (); i++)
629     {
630       if (Slur::has_interface (extra_encompasses[i]))
631         {
632           Grob *small_slur = extra_encompasses[i];
633           Bezier b = Slur::get_curve (small_slur);
634
635           Offset z = b.curve_point (0.5);
636           z += Offset (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
637                        small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
638
639           z[Y_AXIS] += dir_ * parameters_.free_slur_distance_;
640           avoid.push_back (z);
641         }
642       else if (extra_encompasses[i]->get_property ("avoid-slur") == ly_symbol2scm ("inside"))
643         {
644           Grob *g = extra_encompasses [i];
645           Interval xe = g->extent (common_[X_AXIS], X_AXIS);
646           Interval ye = g->extent (common_[Y_AXIS], Y_AXIS);
647
648           if (!xe.is_empty ()
649               && !ye.is_empty ())
650             avoid.push_back (Offset (xe.center (), ye[dir_]));
651         }
652     }
653   return avoid;
654 }
655
656 void
657 Slur_score_state::generate_curves () const
658 {
659   Real r_0 = robust_scm2double (slur_->get_property ("ratio"), 0.33);
660   Real h_inf = staff_space_ * scm_to_double (slur_->get_property ("height-limit"));
661
662   vector<Offset> avoid = generate_avoid_offsets ();
663   for (vsize i = 0; i < configurations_.size (); i++)
664     configurations_[i]->generate_curve (*this, r_0, h_inf, avoid);
665 }
666
667 vector<Slur_configuration *>
668 Slur_score_state::enumerate_attachments (Drul_array<Real> end_ys) const
669 {
670   vector<Slur_configuration *> scores;
671
672   Drul_array<Offset> os;
673   os[LEFT] = base_attachments_[LEFT];
674   Real minimum_length = staff_space_
675                         * robust_scm2double (slur_->get_property ("minimum-length"), 2.0);
676
677   for (int i = 0; dir_ * os[LEFT][Y_AXIS] <= dir_ * end_ys[LEFT]; i++)
678     {
679       os[RIGHT] = base_attachments_[RIGHT];
680       for (int j = 0; dir_ * os[RIGHT][Y_AXIS] <= dir_ * end_ys[RIGHT]; j++)
681         {
682
683           Drul_array<bool> attach_to_stem (false, false);
684           for (LEFT_and_RIGHT (d))
685             {
686               os[d][X_AXIS] = base_attachments_[d][X_AXIS];
687               if (extremes_[d].stem_
688                   && !Stem::is_invisible (extremes_[d].stem_)
689                   && extremes_[d].stem_dir_ == dir_)
690                 {
691                   Interval stem_y = extremes_[d].stem_extent_[Y_AXIS];
692                   stem_y.widen (0.25 * staff_space_);
693                   if (stem_y.contains (os[d][Y_AXIS]))
694                     {
695                       os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS][-d]
696                                       - d * 0.3;
697                       attach_to_stem[d] = true;
698                     }
699                   else if (dir_ * extremes_[d].stem_extent_[Y_AXIS][dir_]
700                            < dir_ * os[d][Y_AXIS]
701                            && !extremes_[d].stem_extent_[X_AXIS].is_empty ())
702
703                     os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS].center ();
704                 }
705             }
706
707           Offset dz;
708           dz = os[RIGHT] - os[LEFT];
709           if (dz[X_AXIS] < minimum_length
710               || fabs (dz[Y_AXIS] / dz[X_AXIS]) > parameters_.max_slope_)
711             {
712               for (LEFT_and_RIGHT (d))
713                 {
714                   if (extremes_[d].slur_head_
715                       && !extremes_[d].slur_head_x_extent_.is_empty ())
716                     {
717                       os[d][X_AXIS] = extremes_[d].slur_head_x_extent_.center ();
718                       attach_to_stem[d] = false;
719                     }
720                 }
721             }
722
723           dz = os[RIGHT] - os[LEFT];
724           for (LEFT_and_RIGHT (d))
725             {
726               if (extremes_[d].slur_head_
727                   && !attach_to_stem[d])
728                 {
729                   /* Horizontally move tilted slurs a little.  Move
730                      more for bigger tilts.
731
732                      TODO: parameter */
733                   os[d][X_AXIS]
734                   -= dir_ * extremes_[d].slur_head_x_extent_.length ()
735                      * sin (dz.arg ()) / 3;
736                 }
737             }
738
739           scores.push_back (Slur_configuration::new_config (os, scores.size ()));
740
741           os[RIGHT][Y_AXIS] += dir_ * staff_space_ / 2;
742         }
743
744       os[LEFT][Y_AXIS] += dir_ * staff_space_ / 2;
745     }
746
747   assert (scores.size () > 0);
748   return scores;
749 }
750
751 vector<Extra_collision_info>
752 Slur_score_state::get_extra_encompass_infos () const
753 {
754   extract_grob_set (slur_, "encompass-objects", encompasses);
755   vector<Extra_collision_info> collision_infos;
756   for (vsize i = encompasses.size (); i--;)
757     {
758       if (Slur::has_interface (encompasses[i]))
759         {
760           Spanner *small_slur = dynamic_cast<Spanner *> (encompasses[i]);
761           Bezier b = Slur::get_curve (small_slur);
762
763           Offset relative (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
764                            small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
765
766           for (int k = 0; k < 3; k++)
767             {
768               Direction hdir = Direction (k - 1);
769
770               /*
771                 Only take bound into account if small slur starts
772                 together with big slur.
773               */
774               if (hdir && small_slur->get_bound (hdir) != slur_->get_bound (hdir))
775                 continue;
776
777               Offset z = b.curve_point (k / 2.0);
778               z += relative;
779
780               Interval yext;
781               yext.set_full ();
782               yext[dir_] = z[Y_AXIS] + dir_ * thickness_ * 1.0;
783
784               Interval xext (-1, 1);
785               xext = xext * (thickness_ * 2) + z[X_AXIS];
786               Extra_collision_info info (small_slur,
787                                          hdir,
788                                          xext,
789                                          yext,
790                                          parameters_.extra_object_collision_penalty_);
791               collision_infos.push_back (info);
792             }
793         }
794       else
795         {
796           Grob *g = encompasses [i];
797           Interval xe = g->extent (common_[X_AXIS], X_AXIS);
798           Interval ye = g->extent (common_[Y_AXIS], Y_AXIS);
799           if (Dots::has_interface (g))
800             ye.widen (0.2);
801
802           Real xp = 0.0;
803           Real penalty = parameters_.extra_object_collision_penalty_;
804           if (Accidental_interface::has_interface (g))
805             {
806               penalty = parameters_.accidental_collision_;
807
808               Rational alt = ly_scm2rational (g->get_property ("alteration"));
809               SCM scm_style = g->get_property ("style");
810               if (!scm_is_symbol (scm_style)
811                   && !to_boolean (g->get_property ("parenthesized"))
812                   && !to_boolean (g->get_property ("restore-first")))
813                 {
814                   /* End copy accidental.cc */
815                   if (alt == FLAT_ALTERATION
816                       || alt == DOUBLE_FLAT_ALTERATION)
817                     xp = LEFT;
818                   else if (alt == SHARP_ALTERATION)
819                     xp = 0.5 * dir_;
820                   else if (alt == NATURAL_ALTERATION)
821                     xp = -dir_;
822                 }
823             }
824
825           ye.widen (thickness_ * 0.5);
826           xe.widen (thickness_ * 1.0);
827           Extra_collision_info info (g, xp, xe, ye, penalty);
828           collision_infos.push_back (info);
829         }
830     }
831
832   return collision_infos;
833 }
834
835 Extra_collision_info::Extra_collision_info (Grob *g, Real idx, Interval x, Interval y, Real p)
836 {
837   idx_ = idx;
838   extents_[X_AXIS] = x;
839   extents_[Y_AXIS] = y;
840   penalty_ = p;
841   grob_ = g;
842   type_ = g->get_property ("avoid-slur");
843 }
844
845 Extra_collision_info::Extra_collision_info ()
846 {
847   idx_ = 0.0;
848   penalty_ = 0.;
849   grob_ = 0;
850   type_ = SCM_EOL;
851 }