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