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   - short-cut: try a smaller region first.
  36
  37   - handle non-visible stems better.
  38
  39   - try to prune number of scoring criteria
  40
  41   - take encompass-objects more into account when determining
  42   slur shape
  43
  44   - calculate encompass scoring directly after determining slur shape.
  45
  46   - optimize.
  47 */
  48 struct Slur_score_state;
  49
  50 Slur_score_state::Slur_score_state ()
  51 {
  52   musical_dy_ = 0.0;
  53   valid_ = false;
  54   edge_has_beams_ = false;
  55   has_same_beam_ = false;
  56   is_broken_ = false;
  57   dir_ = CENTER;
  58   slur_ = 0;
  59   common_[X_AXIS] = 0;
  60   common_[Y_AXIS] = 0;
  61 }
  62
  63 Slur_score_state::~Slur_score_state ()
  64 {
  65   junk_pointers (configurations_);
  66 }
  67
  68 Real
  69 get_detail (SCM alist, SCM sym)
  70 {
  71   SCM entry = scm_assq (sym, alist);
  72   return robust_scm2double (scm_is_pair (entry)
  73                             ? scm_cdr (entry)
  74                             : SCM_EOL,
  75                             0.0);
  76 }
  77
  78 void
  79 Slur_score_parameters::fill (Grob *me)
  80 {
  81   SCM details = me->get_property ("slur-details");
  82
  83   region_size_
  84     = (int) get_detail (details, ly_symbol2scm ("region-size"));
  85   head_encompass_penalty_
  86     = get_detail (details, ly_symbol2scm ("head-encompass-penalty"));
  87   stem_encompass_penalty_
  88     = get_detail (details, ly_symbol2scm ("stem-encompass-penalty"));
  89   closeness_factor_
  90     = get_detail (details, ly_symbol2scm ("closeness-factor"));
  91   edge_attraction_factor_
  92     = get_detail (details, ly_symbol2scm ("edge-attraction-factor"));
  93   same_slope_penalty_
  94     = get_detail (details, ly_symbol2scm ("same-slope-penalty"));
  95   steeper_slope_factor_
  96     = get_detail (details, ly_symbol2scm ("steeper-slope-factor"));
  97   non_horizontal_penalty_
  98     = get_detail (details, ly_symbol2scm ("non-horizontal-penalty"));
  99   max_slope_
 100     = get_detail (details, ly_symbol2scm ("max-slope"));
 101   max_slope_factor_
 102     = get_detail (details, ly_symbol2scm ("max-slope-factor"));
 103   free_head_distance_
 104     = get_detail (details, ly_symbol2scm ("free-head-distance"));
 105   absolute_closeness_measure_
 106     = get_detail (details, ly_symbol2scm ("absolute-closeness-measure"));
 107   extra_object_collision_
 108     = get_detail (details, ly_symbol2scm ("extra-object-collision"));
 109   accidental_collision_
 110     = get_detail (details, ly_symbol2scm ("accidental-collision"));
 111   extra_encompass_free_distance_
 112     = get_detail (details, ly_symbol2scm ("extra-encompass-free-distance"));
 113   head_slur_distance_factor_
 114     = get_detail (details, ly_symbol2scm ("head-slur-distance-factor"));
 115   head_slur_distance_max_ratio_
 116     = get_detail (details, ly_symbol2scm ("head-slur-distance-max-ratio"));
 117   free_slur_distance_
 118     = get_detail (details, ly_symbol2scm ("free-slur-distance"));
 119   edge_slope_exponent_
 120     = get_detail (details, ly_symbol2scm ("edge-slope-exponent"));
 121 }
 122
 123 Real
 124 broken_trend_y (Slur_score_state const &state, Direction hdir)
 125 {
 126   /* A broken slur should maintain the same vertical trend
 127      the unbroken slur would have had.  */
 128   Real by = 0.0;
 129   if (Spanner *mother = dynamic_cast<Spanner *> (state.slur_->original_))
 130     {
 131       int k = broken_spanner_index (state.slur_);
 132       int j = k + hdir;
 133       if (j < 0 || j >= mother->broken_intos_.size ())
 134         return by;
 135
 136       Grob *neighbor = mother->broken_intos_[j];
 137       Spanner *common_mother
 138         = dynamic_cast<Spanner *> (state.common_[Y_AXIS]->original_);
 139       int common_k
 140         = broken_spanner_index (dynamic_cast<Spanner *> (state.common_[Y_AXIS]));
 141       int common_j = common_k + hdir;
 142
 143       if (common_j < 0 || common_j >= common_mother->broken_intos_.size ())
 144         return by;
 145
 146       Grob *common_next_system = common_mother->broken_intos_[common_j];
 147
 148       SCM last_point = scm_car (scm_last_pair (neighbor->get_property ("control-points")));
 149
 150       return scm_to_double (scm_cdr (last_point))
 151         + neighbor->relative_coordinate (common_next_system, Y_AXIS);
 152     }
 153   return by;
 154 }
 155
 156 /*
 157   copy slur dir forwards across line break.
 158 */
 159 void
 160 Slur_score_state::set_next_direction ()
 161 {
 162   if (extremes_[RIGHT].note_column_)
 163     return;
 164
 165   if (Spanner *mother = dynamic_cast<Spanner *> (slur_->original_))
 166     {
 167       int k = broken_spanner_index (slur_);
 168       int j = k + 1;
 169       if (j < 0 || j >= mother->broken_intos_.size ())
 170         return;
 171
 172       Grob *neighbor = mother->broken_intos_[j];
 173       set_grob_direction (neighbor, dir_);
 174     }
 175 }
 176
 177 Encompass_info
 178 Slur_score_state::get_encompass_info (Grob *col) const
 179 {
 180   Grob *stem = unsmob_grob (col->get_property ("stem"));
 181   Encompass_info ei;
 182
 183   if (!stem)
 184     {
 185       programming_error ("no stem for note column");
 186       ei.x_ = col->relative_coordinate (common_[X_AXIS], X_AXIS);
 187       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS],
 188                                          Y_AXIS)[dir_];
 189       return ei;
 190     }
 191   Direction stem_dir = get_grob_direction (stem);
 192
 193   if (Grob *head = Note_column::first_head (col))
 194     ei.x_ = head->extent (common_[X_AXIS], X_AXIS).center ();
 195   else
 196     ei.x_ = col->extent (common_[X_AXIS], X_AXIS).center ();
 197
 198   Grob *h = Stem::extremal_heads (stem)[Direction (dir_)];
 199   if (!h)
 200     {
 201       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 202       return ei;
 203     }
 204
 205   ei.head_ = h->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 206
 207   if ((stem_dir == dir_)
 208       && !stem->extent (stem, Y_AXIS).is_empty ())
 209     {
 210       ei.stem_ = stem->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 211       if (Grob *b = Stem::get_beam (stem))
 212         ei.stem_ += stem_dir * 0.5 * Beam::get_thickness (b);
 213
 214       Interval x = stem->extent (common_[X_AXIS], X_AXIS);
 215       ei.x_ = x.is_empty ()
 216         ? stem->relative_coordinate (common_[X_AXIS], X_AXIS)
 217         : x.center ();
 218     }
 219   else
 220     ei.stem_ = ei.head_;
 221
 222   return ei;
 223 }
 224
 225 Drul_array<Bound_info>
 226 Slur_score_state::get_bound_info () const
 227 {
 228   Drul_array<Bound_info> extremes;
 229
 230   Direction d = LEFT;
 231   Direction dir = dir_;
 232
 233   do
 234     {
 235       extremes[d].bound_ = slur_->get_bound (d);
 236       if (Note_column::has_interface (extremes[d].bound_))
 237         {
 238           extremes[d].note_column_ = extremes[d].bound_;
 239           extremes[d].stem_ = Note_column::get_stem (extremes[d].note_column_);
 240           extremes[d].stem_dir_ = get_grob_direction (extremes[d].stem_);
 241
 242           for (int a = X_AXIS; a < NO_AXES; a++)
 243             {
 244               Axis ax = Axis (a);
 245               Interval s = extremes[d].stem_->extent (common_[ax], ax);
 246               if (s.is_empty ())
 247                 {
 248                   /*
 249                     do not issue warning. This happens for rests and
 250                     whole notes.
 251                   */
 252                   s = Interval (0,0)
 253                     + extremes[d].stem_->relative_coordinate (common_[ax], ax);
 254                 }
 255               extremes[d].stem_extent_[ax] = s;
 256             }
 257
 258           extremes[d].slur_head_
 259             = Stem::extremal_heads (extremes[d].stem_)[dir];
 260           if (!extremes[d].slur_head_
 261               && Note_column::has_rests (extremes[d].bound_))
 262             {
 263               extremes[d].slur_head_ = Note_column::get_rest (extremes[d].bound_);
 264             }
 265
 266           if (extremes[d].slur_head_)
 267             extremes[d].slur_head_extent_
 268               = extremes[d].slur_head_->extent (common_[X_AXIS], X_AXIS);
 269
 270           extremes[d].staff_ = Staff_symbol_referencer
 271             ::get_staff_symbol (extremes[d].stem_);
 272           extremes[d].staff_space_ = Staff_symbol_referencer
 273             ::staff_space (extremes[d].stem_);
 274         }
 275     }
 276   while (flip (&d) != LEFT);
 277
 278   return extremes;
 279 }
 280
 281 void
 282 Slur_score_state::fill (Grob *me)
 283 {
 284   slur_ = dynamic_cast<Spanner *> (me);
 285   columns_
 286     = extract_grob_array (me, ly_symbol2scm ("note-columns"));
 287
 288   if (columns_.is_empty ())
 289     {
 290       me->suicide ();
 291       return;
 292     }
 293
 294   staff_space_ = Staff_symbol_referencer::staff_space (me);
 295   Real lt = me->get_layout ()->get_dimension (ly_symbol2scm ("linethickness"));
 296   thickness_ = robust_scm2double (me->get_property ("thickness"), 1.0) * lt;
 297
 298   dir_ = get_grob_direction (me);
 299   parameters_.fill (me);
 300
 301   SCM eltlist = me->get_property ("note-columns");
 302   SCM extra_list = me->get_property ("encompass-objects");
 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_list (eltlist, me, a);
 309       common_[a] = common_refpoint_of_list (extra_list, 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     {
 380       best = state.configurations_[state.get_closest_index (end_ys)]->curve_;
 381     }
 382   else
 383     {
 384       best = state.get_best_curve ();
 385     }
 386
 387   SCM controls = SCM_EOL;
 388   for (int i = 4; i--;)
 389     {
 390       Offset o = best.control_[i]
 391         - Offset (me->relative_coordinate (state.common_[X_AXIS], X_AXIS),
 392                   me->relative_coordinate (state.common_[Y_AXIS], Y_AXIS));
 393       controls = scm_cons (ly_offset2scm (o), controls);
 394     }
 395   me->set_property ("control-points", controls);
 396 }
 397
 398 Bezier
 399 Slur_score_state::get_best_curve ()
 400 {
 401   int opt_idx = -1;
 402   Real opt = 1e6;
 403
 404 #if DEBUG_SLUR_SCORING
 405   SCM inspect_quants = slur_->get_property ("inspect-quants");
 406   if (to_boolean (slur_->get_layout ()
 407                   ->lookup_variable (ly_symbol2scm ("debug-slur-scoring")))
 408       && scm_is_pair (inspect_quants))
 409     {
 410       opt_idx = get_closest_index (inspect_quants);
 411       configurations_[opt_idx]->score (*this);
 412       opt = configurations_[opt_idx]->score_;
 413     }
 414   else
 415 #endif
 416     {
 417       for (int i = 0; i < configurations_.size (); i++)
 418         {
 419           configurations_[i]->score (*this);
 420         }
 421       for (int i = 0; i < configurations_.size (); i++)
 422         {
 423           if (configurations_[i]->score_ < opt)
 424             {
 425               opt = configurations_[i]->score_;
 426               opt_idx = i;
 427             }
 428         }
 429     }
 430
 431 #if DEBUG_SLUR_SCORING
 432   configurations_[opt_idx]->score_card_ += to_string ("=%.2f", opt);
 433   configurations_[opt_idx]->score_card_ += to_string ("i%d", opt_idx);
 434
 435   // debug quanting
 436   slur_->set_property ("quant-score",
 437                        scm_makfrom0str (configurations_[opt_idx]->score_card_.to_str0 ()));
 438
 439 #endif
 440
 441   return configurations_[opt_idx]->curve_;
 442 }
 443
 444 int
 445 Slur_score_state::get_closest_index (SCM inspect_quants) const
 446 {
 447   Drul_array<Real> ins = ly_scm2interval (inspect_quants);
 448
 449   int opt_idx = -1;
 450   Real mindist = 1e6;
 451   for (int i = 0; i < configurations_.size (); i++)
 452     {
 453       Real d = fabs (configurations_[i]->attachment_[LEFT][Y_AXIS] - ins[LEFT])
 454         + fabs (configurations_[i]->attachment_[RIGHT][Y_AXIS] - ins[RIGHT]);
 455       if (d < mindist)
 456         {
 457           opt_idx = i;
 458           mindist = d;
 459         }
 460     }
 461   if (mindist > 1e5)
 462     programming_error ("can't not find quant");
 463   return opt_idx;
 464 }
 465
 466 /*
 467   TODO: should analyse encompasses to determine sensible region, and
 468   should limit slopes available.
 469 */
 470
 471 Drul_array<Real>
 472 Slur_score_state::get_y_attachment_range () const
 473 {
 474   Drul_array<Real> end_ys;
 475   Direction d = LEFT;
 476   do
 477     {
 478       if (extremes_[d].note_column_)
 479         {
 480           end_ys[d] = dir_
 481             * max (max (dir_ * (base_attachments_[d][Y_AXIS] + parameters_.region_size_ * dir_),
 482                         dir_ * (dir_ + extremes_[d].note_column_->extent (common_[Y_AXIS], Y_AXIS)[dir_])),
 483                    dir_ * base_attachments_[-d][Y_AXIS]);
 484         }
 485       else
 486         end_ys[d] = base_attachments_[d][Y_AXIS] + parameters_.region_size_ * dir_;
 487     }
 488   while (flip (&d) != LEFT);
 489
 490   return end_ys;
 491 }
 492
 493 bool
 494 spanner_less (Spanner *s1, Spanner *s2)
 495 {
 496   Slice b1, b2;
 497   Direction d = LEFT;
 498   do
 499     {
 500       b1[d] = s1->get_bound (d)->get_column ()->rank_;
 501       b2[d] = s2->get_bound (d)->get_column ()->rank_;
 502     }
 503   while (flip (&d) != LEFT);
 504
 505   return b2[LEFT] <= b1[LEFT] && b2[RIGHT] >= b1[RIGHT]
 506     && (b2[LEFT] != b1[LEFT] || b2[RIGHT] != b1[RIGHT]);
 507 }
 508
 509 Drul_array<Offset>
 510 Slur_score_state::get_base_attachments () const
 511 {
 512   Drul_array<Offset> base_attachment;
 513   Direction d = LEFT;
 514   do
 515     {
 516       Grob *stem = extremes_[d].stem_;
 517       Grob *head = extremes_[d].slur_head_;
 518
 519       Real x = 0.0;
 520       Real y = 0.0;
 521       if (extremes_[d].note_column_)
 522         {
 523
 524           /*
 525             fixme: X coord should also be set in this case.
 526           */
 527           if (stem
 528               && !Stem::is_invisible (stem)
 529               && extremes_[d].stem_dir_ == dir_
 530               && Stem::get_beaming (stem, -d)
 531               && (!spanner_less (slur_, Stem::get_beam (stem))
 532                   || has_same_beam_))
 533             y = extremes_[d].stem_extent_[Y_AXIS][dir_];
 534           else if (head)
 535             y = head->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 536           y += dir_ * 0.5 * staff_space_;
 537
 538           y = move_away_from_staffline (y, head);
 539
 540           Grob *fh = Note_column::first_head (extremes_[d].note_column_);
 541           x
 542             = (fh ? fh->extent (common_[X_AXIS], X_AXIS)
 543                : extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS))
 544             .linear_combination (CENTER);
 545         }
 546       base_attachment[d] = Offset (x, y);
 547     }
 548   while (flip (&d) != LEFT);
 549
 550   do
 551     {
 552       if (!extremes_[d].note_column_)
 553         {
 554           Real x, y;
 555           if (d == RIGHT)
 556             {
 557               x = extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS)[d];
 558             }
 559           else
 560             {
 561               x = slur_->get_broken_left_end_align ();
 562             }
 563           Grob *col = (d == LEFT) ? columns_[0] : columns_.top ();
 564
 565           if (extremes_[-d].bound_ != col)
 566             {
 567               y = robust_relative_extent (col, common_[Y_AXIS], Y_AXIS)[dir_];
 568               y += dir_ * 0.5 * staff_space_;
 569
 570               if (get_grob_direction (col) == dir_
 571                   && Note_column::get_stem (col)
 572                   && !Stem::is_invisible (Note_column::get_stem (col)))
 573                 y -= dir_ * 1.5 * staff_space_;
 574             }
 575           else
 576             y = base_attachment[-d][Y_AXIS];
 577
 578           y = move_away_from_staffline (y, col);
 579
 580           base_attachment[d] = Offset (x, y);
 581         }
 582     }
 583   while (flip (&d) != LEFT);
 584
 585
 586   do
 587     {
 588       for (int a = X_AXIS; a < NO_AXES; a++)
 589         {
 590           Real &b = base_attachment[d][Axis (a)];
 591
 592           if (isinf (b) || isnan (b))
 593             {
 594               programming_error ("slur attachment is inf/nan");
 595               b = 0.0;
 596             }
 597
 598         }
 599     }
 600   while (flip (&d) != LEFT);
 601
 602
 603   return base_attachment;
 604 }
 605
 606 Real
 607 Slur_score_state::move_away_from_staffline (Real y,
 608                                             Grob *on_staff) const
 609 {
 610   Grob * staff_symbol = Staff_symbol_referencer::get_staff_symbol (on_staff);
 611   if (!staff_symbol)
 612     return y;
 613
 614   Real pos
 615     = (y - staff_symbol->relative_coordinate (common_[Y_AXIS],
 616                                                                                       Y_AXIS))
 617     * 2.0 / staff_space_;
 618
 619   if (fabs (pos - my_round (pos)) < 0.2
 620       && Staff_symbol_referencer::on_staffline (on_staff, (int) rint (pos))
 621       && Staff_symbol_referencer::line_count (on_staff) - 1 >= rint (pos))
 622     y += 1.5 * staff_space_ * dir_ / 10;
 623
 624   return y;
 625 }
 626
 627
 628
 629 Array<Offset>
 630 Slur_score_state::generate_avoid_offsets () const
 631 {
 632   Array<Offset> avoid;
 633   Link_array<Grob> encompasses = columns_;
 634
 635   for (int i = 0; i < encompasses.size (); i++)
 636     {
 637       if (extremes_[LEFT].note_column_ == encompasses[i]
 638           || extremes_[RIGHT].note_column_ == encompasses[i])
 639         continue;
 640
 641       Encompass_info inf (get_encompass_info (encompasses[i]));
 642       Real y = dir_ * (max (dir_ * inf.head_, dir_ * inf.stem_));
 643
 644       avoid.push (Offset (inf.x_, y + dir_ * parameters_.free_head_distance_));
 645     }
 646
 647   Link_array<Grob> extra_encompasses
 648     = extract_grob_array (slur_, ly_symbol2scm ("encompass-objects"));
 649   for (int i = 0; i < extra_encompasses.size (); i++)
 650     if (Slur::has_interface (extra_encompasses[i]))
 651       {
 652         Grob *small_slur = extra_encompasses[i];
 653         Bezier b = Slur::get_curve (small_slur);
 654
 655         Offset z = b.curve_point (0.5);
 656         z += Offset (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
 657                      small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
 658
 659         z[Y_AXIS] += dir_ * parameters_.free_slur_distance_;
 660         avoid.push (z);
 661       }
 662
 663   return avoid;
 664 }
 665
 666 void
 667 Slur_score_state::generate_curves () const
 668 {
 669   Real r_0 = robust_scm2double (slur_->get_property ("ratio"), 0.33);
 670   Real h_inf = staff_space_ * scm_to_double (slur_->get_property ("height-limit"));
 671
 672   Array<Offset> avoid = generate_avoid_offsets ();
 673   for (int i = 0; i < configurations_.size (); i++)
 674     configurations_[i]->generate_curve (*this, r_0, h_inf, avoid);
 675 }
 676
 677 Link_array<Slur_configuration>
 678 Slur_score_state::enumerate_attachments (Drul_array<Real> end_ys) const
 679 {
 680   Link_array<Slur_configuration> scores;
 681
 682   Drul_array<Offset> os;
 683   os[LEFT] = base_attachments_[LEFT];
 684   Real minimum_length = staff_space_
 685     * robust_scm2double (slur_->get_property ("minimum-length"), 2.0);
 686
 687   for (int i = 0; dir_ * os[LEFT][Y_AXIS] <= dir_ * end_ys[LEFT]; i++)
 688     {
 689       os[RIGHT] = base_attachments_[RIGHT];
 690       for (int j = 0; dir_ * os[RIGHT][Y_AXIS] <= dir_ * end_ys[RIGHT]; j++)
 691         {
 692           Slur_configuration s;
 693           Direction d = LEFT;
 694           Drul_array<bool> attach_to_stem (false, false);
 695           do
 696             {
 697               os[d][X_AXIS] = base_attachments_[d][X_AXIS];
 698               if (extremes_[d].stem_
 699                   && !Stem::is_invisible (extremes_[d].stem_)
 700                   && extremes_[d].stem_dir_ == dir_)
 701                 {
 702                   Interval stem_y = extremes_[d].stem_extent_[Y_AXIS];
 703                   stem_y.widen (0.25 * staff_space_);
 704                   if (stem_y.contains (os[d][Y_AXIS]))
 705                     {
 706                       os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS][-d]
 707                         - d * 0.3;
 708                       attach_to_stem[d] = true;
 709                     }
 710                   else if (dir_ * extremes_[d].stem_extent_[Y_AXIS][dir_]
 711                            < dir_ * os[d][Y_AXIS]
 712                            && !extremes_[d].stem_extent_[X_AXIS].is_empty ())
 713
 714                     os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS].center ();
 715                 }
 716             }
 717           while (flip (&d) != LEFT);
 718
 719           Offset dz;
 720           dz = os[RIGHT] - os[LEFT];
 721           if (dz[X_AXIS] < minimum_length
 722               || fabs (dz[Y_AXIS] / dz[X_AXIS]) > parameters_.max_slope_)
 723             {
 724               do
 725                 {
 726                   if (extremes_[d].slur_head_)
 727                     {
 728                       os[d][X_AXIS] = extremes_[d].slur_head_extent_.center ();
 729                       attach_to_stem[d] = false;
 730                     }
 731                 }
 732               while (flip (&d) != LEFT);
 733             }
 734
 735           dz = os[RIGHT] - os[LEFT];
 736           do
 737             {
 738               if (extremes_[d].slur_head_
 739                   && !attach_to_stem[d])
 740                 {
 741                   /* Horizontally move tilted slurs a little.  Move
 742                      more for bigger tilts.
 743
 744                      TODO: parameter */
 745                   os[d][X_AXIS]
 746                     -= dir_ * extremes_[d].slur_head_extent_.length ()
 747                     * sin (dz.arg ()) / 3;
 748                 }
 749             }
 750           while (flip (&d) != LEFT);
 751
 752           s.attachment_ = os;
 753           s.index_ = scores.size ();
 754
 755           scores.push (new Slur_configuration (s));
 756
 757           os[RIGHT][Y_AXIS] += dir_ * staff_space_ / 2;
 758         }
 759
 760       os[LEFT][Y_AXIS] += dir_ * staff_space_ / 2;
 761     }
 762
 763   assert (scores.size () > 0);
 764   return scores;
 765 }
 766
 767 Array<Extra_collision_info>
 768 Slur_score_state::get_extra_encompass_infos () const
 769 {
 770   Link_array<Grob> encompasses
 771     = extract_grob_array (slur_, ly_symbol2scm ("encompass-objects"));
 772   Array<Extra_collision_info> collision_infos;
 773   for (int i = encompasses.size (); i--;)
 774     {
 775       if (Slur::has_interface (encompasses[i]))
 776         {
 777           Spanner *small_slur = dynamic_cast<Spanner *> (encompasses[i]);
 778           Bezier b = Slur::get_curve (small_slur);
 779
 780           Offset relative (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
 781                            small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
 782
 783           for (int k = 0; k < 3; k++)
 784             {
 785               Direction hdir = Direction (k / 2 - 1);
 786
 787               /*
 788                 Only take bound into account if small slur starts
 789                 together with big slur.
 790               */
 791               if (hdir && small_slur->get_bound (hdir) != slur_->get_bound (hdir))
 792                 continue;
 793
 794               Offset z = b.curve_point (k / 2.0);
 795               z += relative;
 796
 797               Interval yext;
 798               yext.set_full ();
 799               yext[dir_] = z[Y_AXIS] + dir_ * thickness_ * 1.0;
 800
 801               Interval xext (-1, 1);
 802               xext = xext * (thickness_ * 2) + z[X_AXIS];
 803               Extra_collision_info info (small_slur,
 804                                          k - 1.0,
 805                                          xext,
 806                                          yext,
 807                                          parameters_.extra_object_collision_);
 808               collision_infos.push (info);
 809             }
 810         }
 811       else
 812         {
 813           Grob *g = encompasses [i];
 814           Interval xe = g->extent (common_[X_AXIS], X_AXIS);
 815           Interval ye = g->extent (common_[Y_AXIS], Y_AXIS);
 816
 817           Real xp = 0.0;
 818           Real penalty = parameters_.extra_object_collision_;
 819           if (Accidental_interface::has_interface (g))
 820             {
 821               penalty = parameters_.accidental_collision_;
 822               /* Begin copy accidental.cc */
 823               bool parens = false;
 824               if (to_boolean (g->get_property ("cautionary")))
 825                 {
 826                   SCM cstyle = g->get_property ("cautionary-style");
 827                   parens = ly_c_equal_p (cstyle, ly_symbol2scm ("parentheses"));
 828                 }
 829
 830               SCM accs = g->get_property ("accidentals");
 831               SCM scm_style = g->get_property ("style");
 832               if (!scm_is_symbol (scm_style)
 833                   && !parens
 834                   && scm_ilength (accs) == 1)
 835                 {
 836                   /* End copy accidental.cc */
 837                   switch (scm_to_int (scm_car (accs)))
 838                     {
 839                     case FLAT:
 840                     case DOUBLE_FLAT:
 841                       xp = LEFT;
 842                       break;
 843                     case SHARP:
 844                       xp = 0.5 * dir_;
 845                       break;
 846                     case NATURAL:
 847                       xp = -dir_;
 848                       break;
 849                     }
 850                 }
 851             }
 852
 853           ye.widen (thickness_ * 0.5);
 854           xe.widen (thickness_ * 1.0);
 855           Extra_collision_info info (g, xp, xe, ye, penalty);
 856           collision_infos.push (info);
 857         }
 858     }
 859
 860   return collision_infos;
 861 }
 862