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                   programming_error ("Stem has no extent in Slur_score_state");
 249                   s = Interval (0,0)
 250                     + extremes[d].stem_->relative_coordinate (common_[ax], ax);
 251                 }
 252               extremes[d].stem_extent_[ax] = s;
 253             }
 254
 255           extremes[d].stem_extent_[Y_AXIS]
 256             = extremes[d].stem_->extent (common_[Y_AXIS], Y_AXIS);
 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             {
 262               extremes[d].slur_head_ = Note_column::get_rest (extremes[d].bound_);
 263             }
 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     = 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   SCM eltlist = me->get_property ("note-columns");
 301   SCM extra_list = me->get_property ("encompass-objects");
 302   Spanner *sp = dynamic_cast<Spanner *> (me);
 303
 304   for (int i = X_AXIS; i < NO_AXES; i++)
 305     {
 306       Axis a = (Axis)i;
 307       common_[a] = common_refpoint_of_list (eltlist, me, a);
 308       common_[a] = common_refpoint_of_list (extra_list, common_[a], a);
 309
 310       Direction d = LEFT;
 311       do
 312         {
 313           /*
 314             If bound is not in note-columns, we don't want to know about
 315             its Y-position
 316           */
 317           if (a != Y_AXIS)
 318             common_[a] = common_[a]->common_refpoint (sp->get_bound (d), a);
 319         }
 320       while (flip (&d) != LEFT);
 321     }
 322
 323   extremes_ = get_bound_info ();
 324   is_broken_ = (!extremes_[LEFT].note_column_
 325                 || !extremes_[RIGHT].note_column_);
 326
 327   has_same_beam_
 328     = (extremes_[LEFT].stem_ && extremes_[RIGHT].stem_
 329        && Stem::get_beam (extremes_[LEFT].stem_) == Stem::get_beam (extremes_[RIGHT].stem_));
 330
 331   base_attachments_ = get_base_attachments ();
 332
 333   Drul_array<Real> end_ys
 334     = get_y_attachment_range ();
 335
 336   configurations_ = enumerate_attachments (end_ys);
 337   for (int i = 0; i < columns_.size (); i++)
 338     encompass_infos_.push (get_encompass_info (columns_[i]));
 339
 340   extra_encompass_infos_ = get_extra_encompass_infos ();
 341   valid_ = true;
 342
 343   musical_dy_ = 0.0;
 344   Direction d = LEFT;
 345   do
 346     {
 347       if (!is_broken_)
 348         musical_dy_ += d
 349           * extremes_[d].slur_head_->relative_coordinate (common_[Y_AXIS], Y_AXIS);
 350     }
 351   while (flip (&d) != LEFT);
 352
 353   edge_has_beams_
 354     = (extremes_[LEFT].stem_ && Stem::get_beam (extremes_[LEFT].stem_))
 355     || (extremes_[RIGHT].stem_ && Stem::get_beam (extremes_[RIGHT].stem_));
 356
 357   set_next_direction ();
 358
 359   if (is_broken_)
 360     musical_dy_ = 0.0;
 361 }
 362
 363 void
 364 set_slur_control_points (Grob *me)
 365 {
 366   Slur_score_state state;
 367   state.fill (me);
 368
 369   if (!state.valid_)
 370     return;
 371
 372   state.generate_curves ();
 373
 374   SCM end_ys = me->get_property ("positions");
 375   Bezier best;
 376
 377   if (is_number_pair (end_ys))
 378     {
 379       best = state.configurations_[state.get_closest_index (end_ys)]->curve_;
 380     }
 381   else
 382     {
 383       best = state.get_best_curve ();
 384     }
 385
 386   SCM controls = SCM_EOL;
 387   for (int i = 4; i--;)
 388     {
 389       Offset o = best.control_[i]
 390         - Offset (me->relative_coordinate (state.common_[X_AXIS], X_AXIS),
 391                   me->relative_coordinate (state.common_[Y_AXIS], Y_AXIS));
 392       controls = scm_cons (ly_offset2scm (o), controls);
 393     }
 394   me->set_property ("control-points", controls);
 395 }
 396
 397 Bezier
 398 Slur_score_state::get_best_curve ()
 399 {
 400   for (int i = 0; i < configurations_.size (); i++)
 401     {
 402       configurations_[i]->score (*this);
 403     }
 404
 405   Real opt = 1e6;
 406   int opt_idx = -1;
 407   for (int i = 0; i < configurations_.size (); i++)
 408     {
 409       if (configurations_[i]->score_ < opt)
 410         {
 411           opt = configurations_[i]->score_;
 412           opt_idx = i;
 413         }
 414     }
 415
 416 #if DEBUG_SLUR_SCORING
 417   SCM inspect_quants = slur_->get_property ("inspect-quants");
 418   if (to_boolean (slur_->get_layout ()
 419                   ->lookup_variable (ly_symbol2scm ("debug-slur-scoring")))
 420       && scm_is_pair (inspect_quants))
 421     opt_idx = get_closest_index (inspect_quants);
 422
 423   configurations_[opt_idx]->score_card_ += to_string ("=%.2f", opt);
 424   configurations_[opt_idx]->score_card_ += to_string ("i%d", opt_idx);
 425
 426   // debug quanting
 427   slur_->set_property ("quant-score",
 428                        scm_makfrom0str (configurations_[opt_idx]->score_card_.to_str0 ()));
 429
 430 #endif
 431
 432   return configurations_[opt_idx]->curve_;
 433 }
 434
 435 int
 436 Slur_score_state::get_closest_index (SCM inspect_quants) const
 437 {
 438   Drul_array<Real> ins = ly_scm2interval (inspect_quants);
 439
 440   int opt_idx = -1;
 441   Real mindist = 1e6;
 442   for (int i = 0; i < configurations_.size (); i++)
 443     {
 444       Real d = fabs (configurations_[i]->attachment_[LEFT][Y_AXIS] - ins[LEFT])
 445         + fabs (configurations_[i]->attachment_[RIGHT][Y_AXIS] - ins[RIGHT]);
 446       if (d < mindist)
 447         {
 448           opt_idx = i;
 449           mindist = d;
 450         }
 451     }
 452   if (mindist > 1e5)
 453     programming_error ("can't not find quant");
 454   return opt_idx;
 455 }
 456
 457 /*
 458   TODO: should analyse encompasses to determine sensible region, and
 459   should limit slopes available.
 460 */
 461
 462 Drul_array<Real>
 463 Slur_score_state::get_y_attachment_range () const
 464 {
 465   Drul_array<Real> end_ys;
 466   Direction d = LEFT;
 467   do
 468     {
 469       if (extremes_[d].note_column_)
 470         {
 471           end_ys[d] = dir_
 472             * max (max (dir_ * (base_attachments_[d][Y_AXIS] + parameters_.region_size_ * dir_),
 473                         dir_ * (dir_ + extremes_[d].note_column_->extent (common_[Y_AXIS], Y_AXIS)[dir_])),
 474                    dir_ * base_attachments_[-d][Y_AXIS]);
 475         }
 476       else
 477         end_ys[d] = base_attachments_[d][Y_AXIS] + parameters_.region_size_ * dir_;
 478     }
 479   while (flip (&d) != LEFT);
 480
 481   return end_ys;
 482 }
 483
 484 bool
 485 spanner_less (Spanner *s1, Spanner *s2)
 486 {
 487   Slice b1, b2;
 488   Direction d = LEFT;
 489   do
 490     {
 491       b1[d] = s1->get_bound (d)->get_column ()->rank_;
 492       b2[d] = s2->get_bound (d)->get_column ()->rank_;
 493     }
 494   while (flip (&d) != LEFT);
 495
 496   return b2[LEFT] <= b1[LEFT] && b2[RIGHT] >= b1[RIGHT]
 497     && (b2[LEFT] != b1[LEFT] || b2[RIGHT] != b1[RIGHT]);
 498 }
 499
 500 Drul_array<Offset>
 501 Slur_score_state::get_base_attachments () const
 502 {
 503   Drul_array<Offset> base_attachment;
 504   Direction d = LEFT;
 505   do
 506     {
 507       Grob *stem = extremes_[d].stem_;
 508       Grob *head = extremes_[d].slur_head_;
 509
 510       Real x = 0.0;
 511       Real y = 0.0;
 512       if (extremes_[d].note_column_)
 513         {
 514
 515           /*
 516             fixme: X coord should also be set in this case.
 517           */
 518           if (stem
 519               && !Stem::is_invisible (stem)
 520               && extremes_[d].stem_dir_ == dir_
 521               && Stem::get_beaming (stem, -d)
 522               && (!spanner_less (slur_, Stem::get_beam (stem))
 523                   || has_same_beam_))
 524             y = extremes_[d].stem_extent_[Y_AXIS][dir_];
 525           else if (head)
 526             y = head->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 527           y += dir_ * 0.5 * staff_space_;
 528
 529           y = move_away_from_staffline (y, head);
 530
 531           Grob *fh = Note_column::first_head (extremes_[d].note_column_);
 532           x
 533             = (fh ? fh->extent (common_[X_AXIS], X_AXIS)
 534                : extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS))
 535             .linear_combination (CENTER);
 536         }
 537       base_attachment[d] = Offset (x, y);
 538     }
 539   while (flip (&d) != LEFT);
 540
 541   do
 542     {
 543       if (!extremes_[d].note_column_)
 544         {
 545           Real x, y;
 546           if (d == RIGHT)
 547             {
 548               x = extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS)[d];
 549             }
 550           else
 551             {
 552               x = slur_->get_broken_left_end_align ();
 553             }
 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
 577   do
 578     {
 579       for (int a = X_AXIS; a < NO_AXES; a++)
 580         {
 581           Real &b = base_attachment[d][Axis (a)];
 582
 583           if (isinf (b) || isnan (b))
 584             {
 585               programming_error ("slur attachment is inf/nan");
 586               b = 0.0;
 587             }
 588
 589         }
 590     }
 591   while (flip (&d) != LEFT);
 592
 593
 594   return base_attachment;
 595 }
 596
 597 Real
 598 Slur_score_state::move_away_from_staffline (Real y,
 599                                             Grob *on_staff) const
 600 {
 601   Grob * staff_symbol = Staff_symbol_referencer::get_staff_symbol (on_staff);
 602   if (!staff_symbol)
 603     return y;
 604
 605   Real pos
 606     = (y - staff_symbol->relative_coordinate (common_[Y_AXIS],
 607                                                                                       Y_AXIS))
 608     * 2.0 / staff_space_;
 609
 610   if (fabs (pos - my_round (pos)) < 0.2
 611       && Staff_symbol_referencer::on_staffline (on_staff, (int) rint (pos))
 612       && Staff_symbol_referencer::line_count (on_staff) - 1 >= rint (pos))
 613     y += 1.5 * staff_space_ * dir_ / 10;
 614
 615   return y;
 616 }
 617
 618 void
 619 Slur_score_state::generate_curves () const
 620 {
 621   Real r_0 = robust_scm2double (slur_->get_property ("ratio"), 0.33);
 622   Real h_inf = staff_space_ * scm_to_double (slur_->get_property ("height-limit"));
 623   for (int i = 0; i < configurations_.size (); i++)
 624     configurations_[i]->generate_curve (*this, r_0, h_inf);
 625 }
 626
 627 Link_array<Slur_configuration>
 628 Slur_score_state::enumerate_attachments (Drul_array<Real> end_ys) const
 629 {
 630   Link_array<Slur_configuration> scores;
 631
 632   Drul_array<Offset> os;
 633   os[LEFT] = base_attachments_[LEFT];
 634   Real minimum_length = staff_space_
 635     * robust_scm2double (slur_->get_property ("minimum-length"), 2.0);
 636
 637   for (int i = 0; dir_ * os[LEFT][Y_AXIS] <= dir_ * end_ys[LEFT]; i++)
 638     {
 639       os[RIGHT] = base_attachments_[RIGHT];
 640       for (int j = 0; dir_ * os[RIGHT][Y_AXIS] <= dir_ * end_ys[RIGHT]; j++)
 641         {
 642           Slur_configuration s;
 643           Direction d = LEFT;
 644           Drul_array<bool> attach_to_stem (false, false);
 645           do
 646             {
 647               os[d][X_AXIS] = base_attachments_[d][X_AXIS];
 648               if (extremes_[d].stem_
 649                   && !Stem::is_invisible (extremes_[d].stem_)
 650                   && extremes_[d].stem_dir_ == dir_)
 651                 {
 652                   Interval stem_y = extremes_[d].stem_extent_[Y_AXIS];
 653                   stem_y.widen (0.25 * staff_space_);
 654                   if (stem_y.contains (os[d][Y_AXIS]))
 655                     {
 656                       os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS][-d]
 657                         - d * 0.3;
 658                       attach_to_stem[d] = true;
 659                     }
 660                   else if (dir_ * extremes_[d].stem_extent_[Y_AXIS][dir_]
 661                            < dir_ * os[d][Y_AXIS]
 662                            && !extremes_[d].stem_extent_[X_AXIS].is_empty ())
 663
 664                     os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS].center ();
 665                 }
 666             }
 667           while (flip (&d) != LEFT);
 668
 669           Offset dz;
 670           dz = os[RIGHT] - os[LEFT];
 671           if (dz[X_AXIS] < minimum_length
 672               || fabs (dz[Y_AXIS] / dz[X_AXIS]) > parameters_.max_slope_)
 673             {
 674               do
 675                 {
 676                   if (extremes_[d].slur_head_)
 677                     {
 678                       os[d][X_AXIS] = extremes_[d].slur_head_extent_.center ();
 679                       attach_to_stem[d] = false;
 680                     }
 681                 }
 682               while (flip (&d) != LEFT);
 683             }
 684
 685           dz = os[RIGHT] - os[LEFT];
 686           do
 687             {
 688               if (extremes_[d].slur_head_
 689                   && !attach_to_stem[d])
 690                 {
 691                   /* Horizontally move tilted slurs a little.  Move
 692                      more for bigger tilts.
 693
 694                      TODO: parameter */
 695                   os[d][X_AXIS]
 696                     -= dir_ * extremes_[d].slur_head_extent_.length ()
 697                     * sin (dz.arg ()) / 3;
 698                 }
 699             }
 700           while (flip (&d) != LEFT);
 701
 702           s.attachment_ = os;
 703           s.index_ = scores.size ();
 704
 705           scores.push (new Slur_configuration (s));
 706
 707           os[RIGHT][Y_AXIS] += dir_ * staff_space_ / 2;
 708         }
 709
 710       os[LEFT][Y_AXIS] += dir_ * staff_space_ / 2;
 711     }
 712
 713   assert (scores.size () > 0);
 714   return scores;
 715 }
 716
 717 Array<Extra_collision_info>
 718 Slur_score_state::get_extra_encompass_infos () const
 719 {
 720   Link_array<Grob> encompasses
 721     = extract_grob_array (slur_, ly_symbol2scm ("encompass-objects"));
 722   Array<Extra_collision_info> collision_infos;
 723   for (int i = encompasses.size (); i--;)
 724     {
 725       if (Slur::has_interface (encompasses[i]))
 726         {
 727           Spanner *small_slur = dynamic_cast<Spanner *> (encompasses[i]);
 728           Bezier b = Slur::get_curve (small_slur);
 729
 730           Offset relative (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
 731                            small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
 732
 733           for (int k = 0; k < 3; k++)
 734             {
 735               Direction hdir = Direction (k / 2 - 1);
 736
 737               /*
 738                 Only take bound into account if small slur starts
 739                 together with big slur.
 740               */
 741               if (hdir && small_slur->get_bound (hdir) != slur_->get_bound (hdir))
 742                 continue;
 743
 744               Offset z = b.curve_point (k / 2.0);
 745               z += relative;
 746
 747               Interval yext;
 748               yext.set_full ();
 749               yext[dir_] = z[Y_AXIS] + dir_ * thickness_ * 1.0;
 750
 751               Interval xext (-1, 1);
 752               xext = xext * (thickness_ * 2) + z[X_AXIS];
 753               Extra_collision_info info (small_slur,
 754                                          k - 1.0,
 755                                          xext,
 756                                          yext,
 757                                          parameters_.extra_object_collision_);
 758               collision_infos.push (info);
 759             }
 760         }
 761       else
 762         {
 763           Grob *g = encompasses [i];
 764           Interval xe = g->extent (common_[X_AXIS], X_AXIS);
 765           Interval ye = g->extent (common_[Y_AXIS], Y_AXIS);
 766
 767           Real xp = 0.0;
 768           Real penalty = parameters_.extra_object_collision_;
 769           if (Accidental_interface::has_interface (g))
 770             {
 771               penalty = parameters_.accidental_collision_;
 772               /* Begin copy accidental.cc */
 773               bool parens = false;
 774               if (to_boolean (g->get_property ("cautionary")))
 775                 {
 776                   SCM cstyle = g->get_property ("cautionary-style");
 777                   parens = ly_c_equal_p (cstyle, ly_symbol2scm ("parentheses"));
 778                 }
 779
 780               SCM accs = g->get_property ("accidentals");
 781               SCM scm_style = g->get_property ("style");
 782               if (!scm_is_symbol (scm_style)
 783                   && !parens
 784                   && scm_ilength (accs) == 1)
 785                 {
 786                   /* End copy accidental.cc */
 787                   switch (scm_to_int (scm_car (accs)))
 788                     {
 789                     case FLAT:
 790                     case DOUBLE_FLAT:
 791                       xp = LEFT;
 792                       break;
 793                     case SHARP:
 794                       xp = 0.5 * dir_;
 795                       break;
 796                     case NATURAL:
 797                       xp = -dir_;
 798                       break;
 799                     }
 800                 }
 801             }
 802
 803           ye.widen (thickness_ * 0.5);
 804           xe.widen (thickness_ * 1.0);
 805           Extra_collision_info info (g, xp, xe, ye, penalty);
 806           collision_infos.push (info);
 807         }
 808     }
 809
 810   return collision_infos;
 811 }
 812