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 <cmath>
  11 using namespace std;
  12
  13 #include "slur-scoring.hh"
  14 #include "libc-extension.hh"
  15 #include "slur-configuration.hh"
  16 #include "beam.hh"
  17 #include "directional-element-interface.hh"
  18 #include "pointer-group-interface.hh"
  19 #include "slur.hh"
  20 #include "note-column.hh"
  21 #include "output-def.hh"
  22 #include "pitch.hh"
  23 #include "spanner.hh"
  24 #include "staff-symbol-referencer.hh"
  25 #include "staff-symbol.hh"
  26 #include "stem.hh"
  27 #include "warn.hh"
  28 #include "paper-column.hh"
  29 #include "accidental-interface.hh"
  30
  31 /*
  32   TODO:
  33
  34   - curve around flag for y coordinate
  35
  36   - short-cut: try a smaller region first.
  37
  38   - handle non-visible stems better.
  39
  40   - try to prune number of scoring criteria
  41
  42   - take encompass-objects more into account when determining
  43   slur shape
  44
  45   - calculate encompass scoring directly after determining slur shape.
  46
  47   - optimize.
  48 */
  49 struct Slur_score_state;
  50
  51 Slur_score_state::Slur_score_state ()
  52 {
  53   musical_dy_ = 0.0;
  54   valid_ = false;
  55   edge_has_beams_ = false;
  56   has_same_beam_ = false;
  57   is_broken_ = false;
  58   dir_ = CENTER;
  59   slur_ = 0;
  60   common_[X_AXIS] = 0;
  61   common_[Y_AXIS] = 0;
  62 }
  63
  64 Slur_score_state::~Slur_score_state ()
  65 {
  66   junk_pointers (configurations_);
  67 }
  68
  69 Real
  70 get_detail (SCM alist, SCM sym)
  71 {
  72   SCM entry = scm_assq (sym, alist);
  73   return robust_scm2double (scm_is_pair (entry)
  74                             ? scm_cdr (entry)
  75                             : SCM_EOL,
  76                             0.0);
  77 }
  78
  79 void
  80 Slur_score_parameters::fill (Grob *me)
  81 {
  82   SCM details = me->get_property ("slur-details");
  83
  84   region_size_
  85     = (int) get_detail (details, ly_symbol2scm ("region-size"));
  86   head_encompass_penalty_
  87     = get_detail (details, ly_symbol2scm ("head-encompass-penalty"));
  88   stem_encompass_penalty_
  89     = get_detail (details, ly_symbol2scm ("stem-encompass-penalty"));
  90   closeness_factor_
  91     = get_detail (details, ly_symbol2scm ("closeness-factor"));
  92   edge_attraction_factor_
  93     = get_detail (details, ly_symbol2scm ("edge-attraction-factor"));
  94   same_slope_penalty_
  95     = get_detail (details, ly_symbol2scm ("same-slope-penalty"));
  96   steeper_slope_factor_
  97     = get_detail (details, ly_symbol2scm ("steeper-slope-factor"));
  98   non_horizontal_penalty_
  99     = get_detail (details, ly_symbol2scm ("non-horizontal-penalty"));
 100   max_slope_
 101     = get_detail (details, ly_symbol2scm ("max-slope"));
 102   max_slope_factor_
 103     = get_detail (details, ly_symbol2scm ("max-slope-factor"));
 104   free_head_distance_
 105     = get_detail (details, ly_symbol2scm ("free-head-distance"));
 106   absolute_closeness_measure_
 107     = get_detail (details, ly_symbol2scm ("absolute-closeness-measure"));
 108   extra_object_collision_
 109     = get_detail (details, ly_symbol2scm ("extra-object-collision"));
 110   accidental_collision_
 111     = get_detail (details, ly_symbol2scm ("accidental-collision"));
 112   extra_encompass_free_distance_
 113     = get_detail (details, ly_symbol2scm ("extra-encompass-free-distance"));
 114   head_slur_distance_factor_
 115     = get_detail (details, ly_symbol2scm ("head-slur-distance-factor"));
 116   head_slur_distance_max_ratio_
 117     = get_detail (details, ly_symbol2scm ("head-slur-distance-max-ratio"));
 118   free_slur_distance_
 119     = get_detail (details, ly_symbol2scm ("free-slur-distance"));
 120   edge_slope_exponent_
 121     = get_detail (details, ly_symbol2scm ("edge-slope-exponent"));
 122 }
 123
 124 Real
 125 broken_trend_y (Slur_score_state const &state, Direction hdir)
 126 {
 127   /* A broken slur should maintain the same vertical trend
 128      the unbroken slur would have had.  */
 129   Real by = 0.0;
 130   if (Spanner *mother = dynamic_cast<Spanner *> (state.slur_->original_))
 131     {
 132       int k = broken_spanner_index (state.slur_);
 133       int j = k + hdir;
 134       if (j < 0 || j >= mother->broken_intos_.size ())
 135         return by;
 136
 137       Grob *neighbor = mother->broken_intos_[j];
 138       Spanner *common_mother
 139         = dynamic_cast<Spanner *> (state.common_[Y_AXIS]->original_);
 140       int common_k
 141         = broken_spanner_index (dynamic_cast<Spanner *> (state.common_[Y_AXIS]));
 142       int common_j = common_k + hdir;
 143
 144       if (common_j < 0 || common_j >= common_mother->broken_intos_.size ())
 145         return by;
 146
 147       Grob *common_next_system = common_mother->broken_intos_[common_j];
 148
 149       SCM last_point = scm_car (scm_last_pair (neighbor->get_property ("control-points")));
 150
 151       return scm_to_double (scm_cdr (last_point))
 152         + neighbor->relative_coordinate (common_next_system, Y_AXIS);
 153     }
 154   return by;
 155 }
 156
 157 /*
 158   copy slur dir forwards across line break.
 159 */
 160 void
 161 Slur_score_state::set_next_direction ()
 162 {
 163   if (extremes_[RIGHT].note_column_)
 164     return;
 165
 166   if (Spanner *mother = dynamic_cast<Spanner *> (slur_->original_))
 167     {
 168       int k = broken_spanner_index (slur_);
 169       int j = k + 1;
 170       if (j < 0 || j >= mother->broken_intos_.size ())
 171         return;
 172
 173       Grob *neighbor = mother->broken_intos_[j];
 174       set_grob_direction (neighbor, dir_);
 175     }
 176 }
 177
 178 Encompass_info
 179 Slur_score_state::get_encompass_info (Grob *col) const
 180 {
 181   Grob *stem = unsmob_grob (col->get_object ("stem"));
 182   Encompass_info ei;
 183
 184   if (!stem)
 185     {
 186       programming_error ("no stem for note column");
 187       ei.x_ = col->relative_coordinate (common_[X_AXIS], X_AXIS);
 188       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS],
 189                                          Y_AXIS)[dir_];
 190       return ei;
 191     }
 192   Direction stem_dir = get_grob_direction (stem);
 193
 194   if (Grob *head = Note_column::first_head (col))
 195     ei.x_ = head->extent (common_[X_AXIS], X_AXIS).center ();
 196   else
 197     ei.x_ = col->extent (common_[X_AXIS], X_AXIS).center ();
 198
 199   Grob *h = Stem::extremal_heads (stem)[Direction (dir_)];
 200   if (!h)
 201     {
 202       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 203       return ei;
 204     }
 205
 206   ei.head_ = h->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 207
 208   if ((stem_dir == dir_)
 209       && !stem->extent (stem, Y_AXIS).is_empty ())
 210     {
 211       ei.stem_ = stem->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 212       if (Grob *b = Stem::get_beam (stem))
 213         ei.stem_ += stem_dir * 0.5 * Beam::get_thickness (b);
 214
 215       Interval x = stem->extent (common_[X_AXIS], X_AXIS);
 216       ei.x_ = x.is_empty ()
 217         ? stem->relative_coordinate (common_[X_AXIS], X_AXIS)
 218         : x.center ();
 219     }
 220   else
 221     ei.stem_ = ei.head_;
 222
 223   return ei;
 224 }
 225
 226 Drul_array<Bound_info>
 227 Slur_score_state::get_bound_info () const
 228 {
 229   Drul_array<Bound_info> extremes;
 230
 231   Direction d = LEFT;
 232   Direction dir = dir_;
 233
 234   do
 235     {
 236       extremes[d].bound_ = slur_->get_bound (d);
 237       if (Note_column::has_interface (extremes[d].bound_))
 238         {
 239           extremes[d].note_column_ = extremes[d].bound_;
 240           extremes[d].stem_ = Note_column::get_stem (extremes[d].note_column_);
 241           extremes[d].stem_dir_ = get_grob_direction (extremes[d].stem_);
 242
 243           for (int a = X_AXIS; a < NO_AXES; a++)
 244             {
 245               Axis ax = Axis (a);
 246               Interval s = extremes[d].stem_->extent (common_[ax], ax);
 247               if (s.is_empty ())
 248                 {
 249                   /*
 250                     do not issue warning. This happens for rests and
 251                     whole notes.
 252                   */
 253                   s = Interval (0, 0)
 254                     + extremes[d].stem_->relative_coordinate (common_[ax], ax);
 255                 }
 256               extremes[d].stem_extent_[ax] = s;
 257             }
 258
 259           extremes[d].slur_head_
 260             = Stem::extremal_heads (extremes[d].stem_)[dir];
 261           if (!extremes[d].slur_head_
 262               && Note_column::has_rests (extremes[d].bound_))
 263             extremes[d].slur_head_ = Note_column::get_rest (extremes[d].bound_);
 264
 265           if (extremes[d].slur_head_)
 266             extremes[d].slur_head_extent_
 267               = extremes[d].slur_head_->extent (common_[X_AXIS], X_AXIS);
 268
 269           extremes[d].staff_ = Staff_symbol_referencer
 270             ::get_staff_symbol (extremes[d].stem_);
 271           extremes[d].staff_space_ = Staff_symbol_referencer
 272             ::staff_space (extremes[d].stem_);
 273         }
 274     }
 275   while (flip (&d) != LEFT);
 276
 277   return extremes;
 278 }
 279
 280 void
 281 Slur_score_state::fill (Grob *me)
 282 {
 283   slur_ = dynamic_cast<Spanner *> (me);
 284   columns_
 285     = internal_extract_grob_array (me, ly_symbol2scm ("note-columns"));
 286
 287   if (columns_.is_empty ())
 288     {
 289       me->suicide ();
 290       return;
 291     }
 292
 293   staff_space_ = Staff_symbol_referencer::staff_space (me);
 294   Real lt = me->get_layout ()->get_dimension (ly_symbol2scm ("linethickness"));
 295   thickness_ = robust_scm2double (me->get_property ("thickness"), 1.0) * lt;
 296
 297   dir_ = get_grob_direction (me);
 298   parameters_.fill (me);
 299
 300   extract_grob_set (me, "note-columns", columns);
 301   extract_grob_set (me, "encompass-objects", extra_objects);
 302
 303   Spanner *sp = dynamic_cast<Spanner *> (me);
 304
 305   for (int i = X_AXIS; i < NO_AXES; i++)
 306     {
 307       Axis a = (Axis)i;
 308       common_[a] = common_refpoint_of_array (columns, me, a);
 309       common_[a] = common_refpoint_of_array (extra_objects, common_[a], a);
 310
 311       Direction d = LEFT;
 312       do
 313         {
 314           /*
 315             If bound is not in note-columns, we don't want to know about
 316             its Y-position
 317           */
 318           if (a != Y_AXIS)
 319             common_[a] = common_[a]->common_refpoint (sp->get_bound (d), a);
 320         }
 321       while (flip (&d) != LEFT);
 322     }
 323
 324   extremes_ = get_bound_info ();
 325   is_broken_ = (!extremes_[LEFT].note_column_
 326                 || !extremes_[RIGHT].note_column_);
 327
 328   has_same_beam_
 329     = (extremes_[LEFT].stem_ && extremes_[RIGHT].stem_
 330        && Stem::get_beam (extremes_[LEFT].stem_) == Stem::get_beam (extremes_[RIGHT].stem_));
 331
 332   base_attachments_ = get_base_attachments ();
 333
 334   Drul_array<Real> end_ys
 335     = get_y_attachment_range ();
 336
 337   configurations_ = enumerate_attachments (end_ys);
 338   for (int i = 0; i < columns_.size (); i++)
 339     encompass_infos_.push (get_encompass_info (columns_[i]));
 340
 341   extra_encompass_infos_ = get_extra_encompass_infos ();
 342   valid_ = true;
 343
 344   musical_dy_ = 0.0;
 345   Direction d = LEFT;
 346   do
 347     {
 348       if (!is_broken_)
 349         musical_dy_ += d
 350           * extremes_[d].slur_head_->relative_coordinate (common_[Y_AXIS], Y_AXIS);
 351     }
 352   while (flip (&d) != LEFT);
 353
 354   edge_has_beams_
 355     = (extremes_[LEFT].stem_ && Stem::get_beam (extremes_[LEFT].stem_))
 356     || (extremes_[RIGHT].stem_ && Stem::get_beam (extremes_[RIGHT].stem_));
 357
 358   set_next_direction ();
 359
 360   if (is_broken_)
 361     musical_dy_ = 0.0;
 362 }
 363
 364 void
 365 set_slur_control_points (Grob *me)
 366 {
 367   Slur_score_state state;
 368   state.fill (me);
 369
 370   if (!state.valid_)
 371     return;
 372
 373   state.generate_curves ();
 374
 375   SCM end_ys = me->get_property ("positions");
 376   Bezier best;
 377
 378   if (is_number_pair (end_ys))
 379     best = state.configurations_[state.get_closest_index (end_ys)]->curve_;
 380   else
 381     best = state.get_best_curve ();
 382
 383   SCM controls = SCM_EOL;
 384   for (int i = 4; i--;)
 385     {
 386       Offset o = best.control_[i]
 387         - Offset (me->relative_coordinate (state.common_[X_AXIS], X_AXIS),
 388                   me->relative_coordinate (state.common_[Y_AXIS], Y_AXIS));
 389       controls = scm_cons (ly_offset2scm (o), controls);
 390     }
 391   me->set_property ("control-points", controls);
 392 }
 393
 394 Bezier
 395 Slur_score_state::get_best_curve ()
 396 {
 397   int opt_idx = -1;
 398   Real opt = 1e6;
 399
 400 #if DEBUG_SLUR_SCORING
 401   SCM inspect_quants = slur_->get_property ("inspect-quants");
 402   if (to_boolean (slur_->get_layout ()
 403                   ->lookup_variable (ly_symbol2scm ("debug-slur-scoring")))
 404       && scm_is_pair (inspect_quants))
 405     {
 406       opt_idx = get_closest_index (inspect_quants);
 407       configurations_[opt_idx]->score (*this);
 408       opt = configurations_[opt_idx]->score_;
 409     }
 410   else
 411 #endif
 412     {
 413       for (int i = 0; i < configurations_.size (); i++)
 414         configurations_[i]->score (*this);
 415       for (int i = 0; i < configurations_.size (); i++)
 416         {
 417           if (configurations_[i]->score_ < opt)
 418             {
 419               opt = configurations_[i]->score_;
 420               opt_idx = i;
 421             }
 422         }
 423     }
 424
 425 #if DEBUG_SLUR_SCORING
 426   configurations_[opt_idx]->score_card_ += to_string ("=%.2f", opt);
 427   configurations_[opt_idx]->score_card_ += to_string ("i%d", opt_idx);
 428
 429   // debug quanting
 430   slur_->set_property ("quant-score",
 431                        scm_makfrom0str (configurations_[opt_idx]->score_card_.to_str0 ()));
 432
 433 #endif
 434
 435   return configurations_[opt_idx]->curve_;
 436 }
 437
 438 int
 439 Slur_score_state::get_closest_index (SCM inspect_quants) const
 440 {
 441   Drul_array<Real> ins = ly_scm2interval (inspect_quants);
 442
 443   int opt_idx = -1;
 444   Real mindist = 1e6;
 445   for (int i = 0; i < configurations_.size (); i++)
 446     {
 447       Real d = fabs (configurations_[i]->attachment_[LEFT][Y_AXIS] - ins[LEFT])
 448         + fabs (configurations_[i]->attachment_[RIGHT][Y_AXIS] - ins[RIGHT]);
 449       if (d < mindist)
 450         {
 451           opt_idx = i;
 452           mindist = d;
 453         }
 454     }
 455   if (mindist > 1e5)
 456     programming_error ("can't not find quant");
 457   return opt_idx;
 458 }
 459
 460 /*
 461   TODO: should analyse encompasses to determine sensible region, and
 462   should limit slopes available.
 463 */
 464
 465 Drul_array<Real>
 466 Slur_score_state::get_y_attachment_range () const
 467 {
 468   Drul_array<Real> end_ys;
 469   Direction d = LEFT;
 470   do
 471     {
 472       if (extremes_[d].note_column_)
 473         {
 474           end_ys[d] = dir_
 475             * max (max (dir_ * (base_attachments_[d][Y_AXIS]
 476                                           + parameters_.region_size_ * dir_),
 477                         dir_ * (dir_ + extremes_[d].note_column_->extent (common_[Y_AXIS], Y_AXIS)[dir_])),
 478                    dir_ * base_attachments_[-d][Y_AXIS]);
 479         }
 480       else
 481         end_ys[d] = base_attachments_[d][Y_AXIS] + parameters_.region_size_ * dir_;
 482     }
 483   while (flip (&d) != LEFT);
 484
 485   return end_ys;
 486 }
 487
 488 bool
 489 spanner_less (Spanner *s1, Spanner *s2)
 490 {
 491   Slice b1, b2;
 492   Direction d = LEFT;
 493   do
 494     {
 495       b1[d] = s1->get_bound (d)->get_column ()->get_rank ();
 496       b2[d] = s2->get_bound (d)->get_column ()->get_rank ();
 497     }
 498   while (flip (&d) != LEFT);
 499
 500   return b2[LEFT] <= b1[LEFT] && b2[RIGHT] >= b1[RIGHT]
 501     && (b2[LEFT] != b1[LEFT] || b2[RIGHT] != b1[RIGHT]);
 502 }
 503
 504 Drul_array<Offset>
 505 Slur_score_state::get_base_attachments () const
 506 {
 507   Drul_array<Offset> base_attachment;
 508   Direction d = LEFT;
 509   do
 510     {
 511       Grob *stem = extremes_[d].stem_;
 512       Grob *head = extremes_[d].slur_head_;
 513
 514       Real x = 0.0;
 515       Real y = 0.0;
 516       if (extremes_[d].note_column_)
 517         {
 518
 519           /*
 520             fixme: X coord should also be set in this case.
 521           */
 522           if (stem
 523               && !Stem::is_invisible (stem)
 524               && extremes_[d].stem_dir_ == dir_
 525               && Stem::get_beaming (stem, -d)
 526               && (!spanner_less (slur_, Stem::get_beam (stem))
 527                   || has_same_beam_))
 528             y = extremes_[d].stem_extent_[Y_AXIS][dir_];
 529           else if (head)
 530             y = head->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 531           y += dir_ * 0.5 * staff_space_;
 532
 533           y = move_away_from_staffline (y, head);
 534
 535           Grob *fh = Note_column::first_head (extremes_[d].note_column_);
 536           x
 537             = (fh ? fh->extent (common_[X_AXIS], X_AXIS)
 538                : extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS))
 539             .linear_combination (CENTER);
 540         }
 541       base_attachment[d] = Offset (x, y);
 542     }
 543   while (flip (&d) != LEFT);
 544
 545   do
 546     {
 547       if (!extremes_[d].note_column_)
 548         {
 549           Real x, y;
 550           if (d == RIGHT)
 551             x = extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS)[d];
 552           else
 553             x = slur_->get_broken_left_end_align ();
 554           Grob *col = (d == LEFT) ? columns_[0] : columns_.top ();
 555
 556           if (extremes_[-d].bound_ != col)
 557             {
 558               y = robust_relative_extent (col, common_[Y_AXIS], Y_AXIS)[dir_];
 559               y += dir_ * 0.5 * staff_space_;
 560
 561               if (get_grob_direction (col) == dir_
 562                   && Note_column::get_stem (col)
 563                   && !Stem::is_invisible (Note_column::get_stem (col)))
 564                 y -= dir_ * 1.5 * staff_space_;
 565             }
 566           else
 567             y = base_attachment[-d][Y_AXIS];
 568
 569           y = move_away_from_staffline (y, col);
 570
 571           base_attachment[d] = Offset (x, y);
 572         }
 573     }
 574   while (flip (&d) != LEFT);
 575
 576   do
 577     {
 578       for (int a = X_AXIS; a < NO_AXES; a++)
 579         {
 580           Real &b = base_attachment[d][Axis (a)];
 581
 582           if (isinf (b) || isnan (b))
 583             {
 584               programming_error ("slur attachment is inf/nan");
 585               b = 0.0;
 586             }
 587         }
 588     }
 589   while (flip (&d) != LEFT);
 590
 591   return base_attachment;
 592 }
 593
 594 Real
 595 Slur_score_state::move_away_from_staffline (Real y,
 596                                             Grob *on_staff) const
 597 {
 598   Grob *staff_symbol = Staff_symbol_referencer::get_staff_symbol (on_staff);
 599   if (!staff_symbol)
 600     return y;
 601
 602   Real pos
 603     = (y - staff_symbol->relative_coordinate (common_[Y_AXIS],
 604                                               Y_AXIS))
 605     * 2.0 / staff_space_;
 606
 607   if (fabs (pos - my_round (pos)) < 0.2
 608       && Staff_symbol_referencer::on_staffline (on_staff, (int) rint (pos))
 609       && Staff_symbol_referencer::line_count (on_staff) - 1 >= rint (pos))
 610     y += 1.5 * staff_space_ * dir_ / 10;
 611
 612   return y;
 613 }
 614
 615 Array<Offset>
 616 Slur_score_state::generate_avoid_offsets () const
 617 {
 618   Array<Offset> avoid;
 619   Link_array<Grob> encompasses = columns_;
 620
 621   for (int i = 0; i < encompasses.size (); i++)
 622     {
 623       if (extremes_[LEFT].note_column_ == encompasses[i]
 624           || extremes_[RIGHT].note_column_ == encompasses[i])
 625         continue;
 626
 627       Encompass_info inf (get_encompass_info (encompasses[i]));
 628       Real y = dir_ * (max (dir_ * inf.head_, dir_ * inf.stem_));
 629
 630       avoid.push (Offset (inf.x_, y + dir_ * parameters_.free_head_distance_));
 631     }
 632
 633   extract_grob_set (slur_, "encompass-objects", extra_encompasses);
 634   for (int i = 0; i < extra_encompasses.size (); i++)
 635     if (Slur::has_interface (extra_encompasses[i]))
 636       {
 637         Grob *small_slur = extra_encompasses[i];
 638         Bezier b = Slur::get_curve (small_slur);
 639
 640         Offset z = b.curve_point (0.5);
 641         z += Offset (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
 642                      small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
 643
 644         z[Y_AXIS] += dir_ * parameters_.free_slur_distance_;
 645         avoid.push (z);
 646       }
 647
 648   return avoid;
 649 }
 650
 651 void
 652 Slur_score_state::generate_curves () const
 653 {
 654   Real r_0 = robust_scm2double (slur_->get_property ("ratio"), 0.33);
 655   Real h_inf = staff_space_ * scm_to_double (slur_->get_property ("height-limit"));
 656
 657   Array<Offset> avoid = generate_avoid_offsets ();
 658   for (int i = 0; i < configurations_.size (); i++)
 659     configurations_[i]->generate_curve (*this, r_0, h_inf, avoid);
 660 }
 661
 662 Link_array<Slur_configuration>
 663 Slur_score_state::enumerate_attachments (Drul_array<Real> end_ys) const
 664 {
 665   Link_array<Slur_configuration> scores;
 666
 667   Drul_array<Offset> os;
 668   os[LEFT] = base_attachments_[LEFT];
 669   Real minimum_length = staff_space_
 670     * robust_scm2double (slur_->get_property ("minimum-length"), 2.0);
 671
 672   for (int i = 0; dir_ * os[LEFT][Y_AXIS] <= dir_ * end_ys[LEFT]; i++)
 673     {
 674       os[RIGHT] = base_attachments_[RIGHT];
 675       for (int j = 0; dir_ * os[RIGHT][Y_AXIS] <= dir_ * end_ys[RIGHT]; j++)
 676         {
 677           Slur_configuration s;
 678           Direction d = LEFT;
 679           Drul_array<bool> attach_to_stem (false, false);
 680           do
 681             {
 682               os[d][X_AXIS] = base_attachments_[d][X_AXIS];
 683               if (extremes_[d].stem_
 684                   && !Stem::is_invisible (extremes_[d].stem_)
 685                   && extremes_[d].stem_dir_ == dir_)
 686                 {
 687                   Interval stem_y = extremes_[d].stem_extent_[Y_AXIS];
 688                   stem_y.widen (0.25 * staff_space_);
 689                   if (stem_y.contains (os[d][Y_AXIS]))
 690                     {
 691                       os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS][-d]
 692                         - d * 0.3;
 693                       attach_to_stem[d] = true;
 694                     }
 695                   else if (dir_ * extremes_[d].stem_extent_[Y_AXIS][dir_]
 696                            < dir_ * os[d][Y_AXIS]
 697                            && !extremes_[d].stem_extent_[X_AXIS].is_empty ())
 698
 699                     os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS].center ();
 700                 }
 701             }
 702           while (flip (&d) != LEFT);
 703
 704           Offset dz;
 705           dz = os[RIGHT] - os[LEFT];
 706           if (dz[X_AXIS] < minimum_length
 707               || fabs (dz[Y_AXIS] / dz[X_AXIS]) > parameters_.max_slope_)
 708             {
 709               do
 710                 {
 711                   if (extremes_[d].slur_head_)
 712                     {
 713                       os[d][X_AXIS] = extremes_[d].slur_head_extent_.center ();
 714                       attach_to_stem[d] = false;
 715                     }
 716                 }
 717               while (flip (&d) != LEFT);
 718             }
 719
 720           dz = os[RIGHT] - os[LEFT];
 721           do
 722             {
 723               if (extremes_[d].slur_head_
 724                   && !attach_to_stem[d])
 725                 {
 726                   /* Horizontally move tilted slurs a little.  Move
 727                      more for bigger tilts.
 728
 729                      TODO: parameter */
 730                   os[d][X_AXIS]
 731                     -= dir_ * extremes_[d].slur_head_extent_.length ()
 732                     * sin (dz.arg ()) / 3;
 733                 }
 734             }
 735           while (flip (&d) != LEFT);
 736
 737           s.attachment_ = os;
 738           s.index_ = scores.size ();
 739
 740           scores.push (new Slur_configuration (s));
 741
 742           os[RIGHT][Y_AXIS] += dir_ * staff_space_ / 2;
 743         }
 744
 745       os[LEFT][Y_AXIS] += dir_ * staff_space_ / 2;
 746     }
 747
 748   assert (scores.size () > 0);
 749   return scores;
 750 }
 751
 752 Array<Extra_collision_info>
 753 Slur_score_state::get_extra_encompass_infos () const
 754 {
 755   extract_grob_set (slur_, "encompass-objects", encompasses);
 756   Array<Extra_collision_info> collision_infos;
 757   for (int i = encompasses.size (); i--;)
 758     {
 759       if (Slur::has_interface (encompasses[i]))
 760         {
 761           Spanner *small_slur = dynamic_cast<Spanner *> (encompasses[i]);
 762           Bezier b = Slur::get_curve (small_slur);
 763
 764           Offset relative (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
 765                            small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
 766
 767           for (int k = 0; k < 3; k++)
 768             {
 769               Direction hdir = Direction (k / 2 - 1);
 770
 771               /*
 772                 Only take bound into account if small slur starts
 773                 together with big slur.
 774               */
 775               if (hdir && small_slur->get_bound (hdir) != slur_->get_bound (hdir))
 776                 continue;
 777
 778               Offset z = b.curve_point (k / 2.0);
 779               z += relative;
 780
 781               Interval yext;
 782               yext.set_full ();
 783               yext[dir_] = z[Y_AXIS] + dir_ * thickness_ * 1.0;
 784
 785               Interval xext (-1, 1);
 786               xext = xext * (thickness_ * 2) + z[X_AXIS];
 787               Extra_collision_info info (small_slur,
 788                                          k - 1.0,
 789                                          xext,
 790                                          yext,
 791                                          parameters_.extra_object_collision_);
 792               collision_infos.push (info);
 793             }
 794         }
 795       else
 796         {
 797           Grob *g = encompasses [i];
 798           Interval xe = g->extent (common_[X_AXIS], X_AXIS);
 799           Interval ye = g->extent (common_[Y_AXIS], Y_AXIS);
 800
 801           Real xp = 0.0;
 802           Real penalty = parameters_.extra_object_collision_;
 803           if (Accidental_interface::has_interface (g))
 804             {
 805               penalty = parameters_.accidental_collision_;
 806               /* Begin copy accidental.cc */
 807               bool parens = false;
 808               if (to_boolean (g->get_property ("cautionary")))
 809                 {
 810                   SCM cstyle = g->get_property ("cautionary-style");
 811                   parens = ly_is_equal (cstyle, ly_symbol2scm ("parentheses"));
 812                 }
 813
 814               SCM accs = g->get_property ("accidentals");
 815               SCM scm_style = g->get_property ("style");
 816               if (!scm_is_symbol (scm_style)
 817                   && !parens
 818                   && scm_ilength (accs) == 1)
 819                 {
 820                   /* End copy accidental.cc */
 821                   switch (scm_to_int (scm_car (accs)))
 822                     {
 823                     case FLAT:
 824                     case DOUBLE_FLAT:
 825                       xp = LEFT;
 826                       break;
 827                     case SHARP:
 828                       xp = 0.5 * dir_;
 829                       break;
 830                     case NATURAL:
 831                       xp = -dir_;
 832                       break;
 833                     }
 834                 }
 835             }
 836
 837           ye.widen (thickness_ * 0.5);
 838           xe.widen (thickness_ * 1.0);
 839           Extra_collision_info info (g, xp, xe, ye, penalty);
 840           collision_infos.push (info);
 841         }
 842     }
 843
 844   return collision_infos;
 845 }
 846