lily/slur-scoring.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1996--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5   Jan Nieuwenhuizen <janneke@gnu.org>
   6
   7   LilyPond is free software: you can redistribute it and/or modify
   8   it under the terms of the GNU General Public License as published by
   9   the Free Software Foundation, either version 3 of the License, or
  10   (at your option) any later version.
  11
  12   LilyPond is distributed in the hope that it will be useful,
  13   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15   GNU General Public License for more details.
  16
  17   You should have received a copy of the GNU General Public License
  18   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21
  22 #include "slur-scoring.hh"
  23
  24 #include <queue>
  25
  26 #include "accidental-interface.hh"
  27 #include "beam.hh"
  28 #include "directional-element-interface.hh"
  29 #include "libc-extension.hh"
  30 #include "main.hh"
  31 #include "note-column.hh"
  32 #include "output-def.hh"
  33 #include "paper-column.hh"
  34 #include "pitch.hh"
  35 #include "pointer-group-interface.hh"
  36 #include "slur-configuration.hh"
  37 #include "slur.hh"
  38 #include "spanner.hh"
  39 #include "staff-symbol-referencer.hh"
  40 #include "staff-symbol.hh"
  41 #include "stem.hh"
  42 #include "warn.hh"
  43
  44 /*
  45   TODO:
  46
  47   - curve around flag for y coordinate
  48
  49   - short-cut: try a smaller region first.
  50
  51   - handle non-visible stems better.
  52
  53   - try to prune number of scoring criteria
  54
  55   - take encompass-objects more into account when determining
  56   slur shape
  57
  58   - calculate encompass scoring directly after determining slur shape.
  59
  60   - optimize.
  61 */
  62 struct Slur_score_state;
  63
  64 Slur_score_state::Slur_score_state ()
  65 {
  66   musical_dy_ = 0.0;
  67   valid_ = false;
  68   edge_has_beams_ = false;
  69   has_same_beam_ = false;
  70   is_broken_ = false;
  71   dir_ = CENTER;
  72   slur_ = 0;
  73   common_[X_AXIS] = 0;
  74   common_[Y_AXIS] = 0;
  75 }
  76
  77 Slur_score_state::~Slur_score_state ()
  78 {
  79   junk_pointers (configurations_);
  80 }
  81
  82 /*
  83   If a slur is broken across a line break, the direction
  84   of the post-break slur must be the same as the pre-break
  85   slur.
  86 */
  87 Direction
  88 Slur_score_state::slur_direction () const
  89 {
  90   Grob *left_neighbor = slur_->broken_neighbor (LEFT);
  91
  92   if (left_neighbor && left_neighbor->is_live ())
  93     return get_grob_direction (left_neighbor);
  94
  95   Direction dir = get_grob_direction (slur_);
  96
  97   if (Grob *right_neighbor = slur_->broken_neighbor (RIGHT))
  98     set_grob_direction (right_neighbor, dir);
  99
 100   return dir;
 101 }
 102
 103 Encompass_info
 104 Slur_score_state::get_encompass_info (Grob *col) const
 105 {
 106   Grob *stem = unsmob_grob (col->get_object ("stem"));
 107   Encompass_info ei;
 108
 109   if (!stem)
 110     {
 111       programming_error ("no stem for note column");
 112       ei.x_ = col->relative_coordinate (common_[X_AXIS], X_AXIS);
 113       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS],
 114                                          Y_AXIS)[dir_];
 115       return ei;
 116     }
 117   Direction stem_dir = get_grob_direction (stem);
 118
 119   if (Grob *head = Note_column::first_head (col))
 120     ei.x_ = head->extent (common_[X_AXIS], X_AXIS).center ();
 121   else
 122     ei.x_ = col->extent (common_[X_AXIS], X_AXIS).center ();
 123
 124   Grob *h = Stem::extremal_heads (stem)[Direction (dir_)];
 125   if (!h)
 126     {
 127       ei.head_ = ei.stem_ = col->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 128       return ei;
 129     }
 130
 131   ei.head_ = h->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 132
 133   if ((stem_dir == dir_)
 134       && !stem->extent (stem, Y_AXIS).is_empty ())
 135     {
 136       ei.stem_ = stem->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 137       if (Grob *b = Stem::get_beam (stem))
 138         ei.stem_ += stem_dir * 0.5 * Beam::get_beam_thickness (b);
 139
 140       Interval x = stem->extent (common_[X_AXIS], X_AXIS);
 141       ei.x_ = x.is_empty ()
 142         ? stem->relative_coordinate (common_[X_AXIS], X_AXIS)
 143         : x.center ();
 144     }
 145   else
 146     ei.stem_ = ei.head_;
 147
 148   return ei;
 149 }
 150
 151 Drul_array<Bound_info>
 152 Slur_score_state::get_bound_info () const
 153 {
 154   Drul_array<Bound_info> extremes;
 155
 156   Direction d = LEFT;
 157   Direction dir = dir_;
 158
 159   do
 160     {
 161       extremes[d].bound_ = slur_->get_bound (d);
 162       if (Note_column::has_interface (extremes[d].bound_))
 163         {
 164           extremes[d].note_column_ = extremes[d].bound_;
 165           extremes[d].stem_ = Note_column::get_stem (extremes[d].note_column_);
 166           if (extremes[d].stem_)
 167             {
 168               extremes[d].stem_dir_ = get_grob_direction (extremes[d].stem_);
 169
 170               for (int a = X_AXIS; a < NO_AXES; a++)
 171                 {
 172                   Axis ax = Axis (a);
 173                   Interval s = extremes[d].stem_->extent (common_[ax], ax);
 174                   if (s.is_empty ())
 175                     {
 176                       /*
 177                         do not issue warning. This happens for rests and
 178                         whole notes.
 179                       */
 180                       s = Interval (0, 0)
 181                         + extremes[d].stem_->relative_coordinate (common_[ax], ax);
 182                     }
 183                   extremes[d].stem_extent_[ax] = s;
 184                 }
 185
 186               extremes[d].slur_head_
 187                 = Stem::extremal_heads (extremes[d].stem_)[dir];
 188               if (!extremes[d].slur_head_
 189                   && Note_column::has_rests (extremes[d].bound_))
 190                 extremes[d].slur_head_ = Note_column::get_rest (extremes[d].bound_);
 191               extremes[d].staff_ = Staff_symbol_referencer
 192                 ::get_staff_symbol (extremes[d].stem_);
 193               extremes[d].staff_space_ = Staff_symbol_referencer
 194                 ::staff_space (extremes[d].stem_);
 195             }
 196
 197           if (extremes[d].slur_head_)
 198             extremes[d].slur_head_x_extent_
 199               = extremes[d].slur_head_->extent (common_[X_AXIS], X_AXIS);
 200
 201         }
 202     }
 203   while (flip (&d) != LEFT);
 204
 205   return extremes;
 206 }
 207
 208 void
 209 Slur_score_state::fill (Grob *me)
 210 {
 211   slur_ = dynamic_cast<Spanner *> (me);
 212   columns_
 213     = internal_extract_grob_array (me, ly_symbol2scm ("note-columns"));
 214
 215   if (columns_.empty ())
 216     {
 217       me->suicide ();
 218       return;
 219     }
 220
 221   Slur::replace_breakable_encompass_objects (me);
 222   staff_space_ = Staff_symbol_referencer::staff_space (me);
 223   Real lt = me->layout ()->get_dimension (ly_symbol2scm ("line-thickness"));
 224   thickness_ = robust_scm2double (me->get_property ("thickness"), 1.0) * lt;
 225
 226   dir_ = slur_direction ();
 227   parameters_.fill (me);
 228
 229   extract_grob_set (me, "note-columns", columns);
 230   extract_grob_set (me, "encompass-objects", extra_objects);
 231
 232   Spanner *sp = dynamic_cast<Spanner *> (me);
 233
 234   for (int i = X_AXIS; i < NO_AXES; i++)
 235     {
 236       Axis a = (Axis)i;
 237       common_[a] = common_refpoint_of_array (columns, me, a);
 238       common_[a] = common_refpoint_of_array (extra_objects, common_[a], a);
 239
 240       Direction d = LEFT;
 241       do
 242         {
 243           /*
 244             If bound is not in note-columns, we don't want to know about
 245             its Y-position
 246           */
 247           if (a != Y_AXIS)
 248             common_[a] = common_[a]->common_refpoint (sp->get_bound (d), a);
 249         }
 250       while (flip (&d) != LEFT);
 251     }
 252
 253   extremes_ = get_bound_info ();
 254   is_broken_ = (!extremes_[LEFT].note_column_
 255                 || !extremes_[RIGHT].note_column_);
 256
 257   has_same_beam_
 258     = (extremes_[LEFT].stem_ && extremes_[RIGHT].stem_
 259        && Stem::get_beam (extremes_[LEFT].stem_) == Stem::get_beam (extremes_[RIGHT].stem_));
 260
 261   base_attachments_ = get_base_attachments ();
 262
 263   Drul_array<Real> end_ys
 264     = get_y_attachment_range ();
 265
 266   configurations_ = enumerate_attachments (end_ys);
 267   for (vsize i = 0; i < columns_.size (); i++)
 268     encompass_infos_.push_back (get_encompass_info (columns_[i]));
 269
 270   extra_encompass_infos_ = get_extra_encompass_infos ();
 271   valid_ = true;
 272
 273   musical_dy_ = 0.0;
 274   Direction d = LEFT;
 275   do
 276     {
 277       if (!is_broken_
 278           && extremes_[d].slur_head_)
 279         musical_dy_ += d
 280           * extremes_[d].slur_head_->relative_coordinate (common_[Y_AXIS], Y_AXIS);
 281     }
 282   while (flip (&d) != LEFT);
 283
 284   edge_has_beams_
 285     = (extremes_[LEFT].stem_ && Stem::get_beam (extremes_[LEFT].stem_))
 286     || (extremes_[RIGHT].stem_ && Stem::get_beam (extremes_[RIGHT].stem_));
 287
 288   if (is_broken_)
 289     musical_dy_ = 0.0;
 290 }
 291
 292
 293 MAKE_SCHEME_CALLBACK (Slur, calc_control_points, 1)
 294 SCM
 295 Slur::calc_control_points (SCM smob)
 296 {
 297   Spanner *me = unsmob_spanner (smob);
 298
 299   Slur_score_state state;
 300   state.fill (me);
 301
 302   if (!state.valid_)
 303     return SCM_EOL;
 304
 305   state.generate_curves ();
 306
 307   SCM end_ys = me->get_property ("positions");
 308   SCM inspect_quants = me->get_property ("inspect-quants");
 309   bool debug_slurs = to_boolean (me->layout ()
 310                                  ->lookup_variable (ly_symbol2scm ("debug-slur-scoring")));
 311
 312   if (is_number_pair (inspect_quants))
 313     {
 314       debug_slurs = true;
 315       end_ys = inspect_quants;
 316     }
 317
 318   Slur_configuration *best = NULL;
 319   if (is_number_pair (end_ys))
 320     best = state.get_forced_configuration (ly_scm2interval(end_ys));
 321   else
 322     best = state.get_best_curve ();
 323
 324 #if DEBUG_SLUR_SCORING
 325   if (debug_slurs)
 326     {
 327       string total = best->card ();
 328       total += to_string (" TOTAL=%.2f idx=%d", best->score (), best->index_);
 329       me->set_property ("annotation", ly_string2scm (total));
 330     }
 331 #endif
 332
 333   SCM controls = SCM_EOL;
 334   for (int i = 4; i--;)
 335     {
 336       Offset o = best->curve_.control_[i]
 337         - Offset (me->relative_coordinate (state.common_[X_AXIS], X_AXIS),
 338                   me->relative_coordinate (state.common_[Y_AXIS], Y_AXIS));
 339       controls = scm_cons (ly_offset2scm (o), controls);
 340     }
 341
 342   return controls;
 343 }
 344
 345 Slur_configuration*
 346 Slur_score_state::get_forced_configuration (Interval ys) const
 347 {
 348   Slur_configuration *best = NULL;
 349   Real mindist = 1e6;
 350   for (vsize i = 0; i < configurations_.size (); i++)
 351     {
 352       Real d = fabs (configurations_[i]->attachment_[LEFT][Y_AXIS] - ys[LEFT])
 353         + fabs (configurations_[i]->attachment_[RIGHT][Y_AXIS] - ys[RIGHT]);
 354       if (d < mindist)
 355         {
 356           best = configurations_[i];
 357           mindist = d;
 358         }
 359     }
 360
 361   while (!best->done ())
 362     best->run_next_scorer (*this);
 363
 364   if (mindist > 1e5)
 365     programming_error ("cannot find quant");
 366
 367   return best;
 368 }
 369
 370
 371 Slur_configuration *
 372 Slur_score_state::get_best_curve () const
 373 {
 374   std::priority_queue<Slur_configuration*, std::vector<Slur_configuration*>,
 375                       Slur_configuration_less> queue;
 376   for (vsize i = 0; i < configurations_.size (); i++)
 377     queue.push (configurations_[i]);
 378
 379   Slur_configuration *best = NULL;
 380   while (true) {
 381     best = queue.top ();
 382     if (best->done ())
 383       break;
 384
 385     queue.pop ();
 386     best->run_next_scorer (*this);
 387     queue.push (best);
 388   }
 389
 390   return best;
 391 }
 392
 393 Grob *
 394 Slur_score_state::breakable_bound_item (Direction d) const
 395 {
 396   Grob *col = slur_->get_bound (d)->get_column ();
 397
 398   extract_grob_set (slur_, "encompass-objects", extra_encompasses);
 399
 400   for (vsize i = 0; i < extra_encompasses.size (); i++)
 401     {
 402       Item *item = dynamic_cast<Item*> (extra_encompasses[i]);
 403       if (item && col == item->get_column ())
 404         return item;
 405     }
 406
 407   return 0;
 408 }
 409
 410 /*
 411   TODO: should analyse encompasses to determine sensible region, and
 412   should limit slopes available.
 413 */
 414
 415 Drul_array<Real>
 416 Slur_score_state::get_y_attachment_range () const
 417 {
 418   Drul_array<Real> end_ys;
 419   Direction d = LEFT;
 420   do
 421     {
 422       if (extremes_[d].note_column_)
 423         {
 424           end_ys[d] = dir_
 425             * max (max (dir_ * (base_attachments_[d][Y_AXIS]
 426                                 + parameters_.region_size_ * dir_),
 427                         dir_ * (dir_ + extremes_[d].note_column_->extent (common_[Y_AXIS], Y_AXIS)[dir_])),
 428                    dir_ * base_attachments_[-d][Y_AXIS]);
 429         }
 430       else
 431         end_ys[d] = base_attachments_[d][Y_AXIS] + parameters_.region_size_ * dir_;
 432     }
 433   while (flip (&d) != LEFT);
 434
 435   return end_ys;
 436 }
 437
 438 bool
 439 spanner_less (Spanner *s1, Spanner *s2)
 440 {
 441   Slice b1, b2;
 442   Direction d = LEFT;
 443   do
 444     {
 445       b1[d] = s1->get_bound (d)->get_column ()->get_rank ();
 446       b2[d] = s2->get_bound (d)->get_column ()->get_rank ();
 447     }
 448   while (flip (&d) != LEFT);
 449
 450   return b2[LEFT] <= b1[LEFT] && b2[RIGHT] >= b1[RIGHT]
 451     && (b2[LEFT] != b1[LEFT] || b2[RIGHT] != b1[RIGHT]);
 452 }
 453
 454 Drul_array<Offset>
 455 Slur_score_state::get_base_attachments () const
 456 {
 457   Drul_array<Offset> base_attachment;
 458   Direction d = LEFT;
 459   do
 460     {
 461       Grob *stem = extremes_[d].stem_;
 462       Grob *head = extremes_[d].slur_head_;
 463
 464       Real x = 0.0;
 465       Real y = 0.0;
 466       if (extremes_[d].note_column_)
 467         {
 468
 469           /*
 470             fixme: X coord should also be set in this case.
 471           */
 472           if (stem
 473               && !Stem::is_invisible (stem)
 474               && extremes_[d].stem_dir_ == dir_
 475               && Stem::get_beaming (stem, -d)
 476               && Stem::get_beam (stem)
 477               && (!spanner_less (slur_, Stem::get_beam (stem))
 478                   || has_same_beam_))
 479             y = extremes_[d].stem_extent_[Y_AXIS][dir_];
 480           else if (head)
 481             y = head->extent (common_[Y_AXIS], Y_AXIS)[dir_];
 482           y += dir_ * 0.5 * staff_space_;
 483
 484           y = move_away_from_staffline (y, head);
 485
 486           Grob *fh = Note_column::first_head (extremes_[d].note_column_);
 487           x
 488             = (fh ? fh->extent (common_[X_AXIS], X_AXIS)
 489                : extremes_[d].bound_->extent (common_[X_AXIS], X_AXIS))
 490             .linear_combination (CENTER);
 491         }
 492       base_attachment[d] = Offset (x, y);
 493     }
 494   while (flip (&d) != LEFT);
 495
 496   do
 497     {
 498       if (!extremes_[d].note_column_)
 499         {
 500           Real x = 0;
 501           Real y = 0;
 502
 503           if (Grob *g = breakable_bound_item (d))
 504             {
 505               x = robust_relative_extent (g, common_[X_AXIS], X_AXIS)[RIGHT];
 506             }
 507           else if (d == RIGHT)
 508             x = robust_relative_extent (extremes_[d].bound_, common_[X_AXIS], X_AXIS)[d];
 509           else
 510             x = slur_->get_broken_left_end_align ();
 511
 512           Grob *col = (d == LEFT) ? columns_[0] : columns_.back ();
 513
 514           if (extremes_[-d].bound_ != col)
 515             {
 516               y = robust_relative_extent (col, common_[Y_AXIS], Y_AXIS)[dir_];
 517               y += dir_ * 0.5 * staff_space_;
 518
 519               if (get_grob_direction (col) == dir_
 520                   && Note_column::get_stem (col)
 521                   && !Stem::is_invisible (Note_column::get_stem (col)))
 522                 y -= dir_ * 1.5 * staff_space_;
 523             }
 524           else
 525             y = base_attachment[-d][Y_AXIS];
 526
 527           y = move_away_from_staffline (y, col);
 528
 529           base_attachment[d] = Offset (x, y);
 530         }
 531     }
 532   while (flip (&d) != LEFT);
 533
 534   do
 535     {
 536       for (int a = X_AXIS; a < NO_AXES; a++)
 537         {
 538           Real &b = base_attachment[d][Axis (a)];
 539
 540           if (isinf (b) || isnan (b))
 541             {
 542               programming_error ("slur attachment is inf/nan");
 543               b = 0.0;
 544             }
 545         }
 546     }
 547   while (flip (&d) != LEFT);
 548
 549   return base_attachment;
 550 }
 551
 552 Real
 553 Slur_score_state::move_away_from_staffline (Real y,
 554                                             Grob *on_staff) const
 555 {
 556   if (!on_staff)
 557     return y;
 558
 559   Grob *staff_symbol = Staff_symbol_referencer::get_staff_symbol (on_staff);
 560   if (!staff_symbol)
 561     return y;
 562
 563   Real pos
 564     = (y - staff_symbol->relative_coordinate (common_[Y_AXIS],
 565                                               Y_AXIS))
 566     * 2.0 / staff_space_;
 567
 568   if (fabs (pos - my_round (pos)) < 0.2
 569       && Staff_symbol_referencer::on_line (on_staff, (int) rint (pos))
 570       && Staff_symbol_referencer::line_count (on_staff) - 1 >= rint (pos))
 571     y += 1.5 * staff_space_ * dir_ / 10;
 572
 573   return y;
 574 }
 575
 576 vector<Offset>
 577 Slur_score_state::generate_avoid_offsets () const
 578 {
 579   vector<Offset> avoid;
 580   vector<Grob*> encompasses = columns_;
 581
 582   for (vsize i = 0; i < encompasses.size (); i++)
 583     {
 584       if (extremes_[LEFT].note_column_ == encompasses[i]
 585           || extremes_[RIGHT].note_column_ == encompasses[i])
 586         continue;
 587
 588       Encompass_info inf (get_encompass_info (encompasses[i]));
 589       Real y = dir_ * (max (dir_ * inf.head_, dir_ * inf.stem_));
 590
 591       avoid.push_back (Offset (inf.x_, y + dir_ * parameters_.free_head_distance_));
 592     }
 593
 594   extract_grob_set (slur_, "encompass-objects", extra_encompasses);
 595   for (vsize i = 0; i < extra_encompasses.size (); i++)
 596     {
 597       if (Slur::has_interface (extra_encompasses[i]))
 598         {
 599           Grob *small_slur = extra_encompasses[i];
 600           Bezier b = Slur::get_curve (small_slur);
 601
 602           Offset z = b.curve_point (0.5);
 603           z += Offset (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
 604                        small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
 605
 606           z[Y_AXIS] += dir_ * parameters_.free_slur_distance_;
 607           avoid.push_back (z);
 608         }
 609       else if (extra_encompasses[i]->get_property ("avoid-slur") == ly_symbol2scm ("inside"))
 610         {
 611           Grob *g = extra_encompasses [i];
 612           Interval xe = g->extent (common_[X_AXIS], X_AXIS);
 613           Interval ye = g->extent (common_[Y_AXIS], Y_AXIS);
 614
 615           if (!xe.is_empty ()
 616               && !ye.is_empty ())
 617             avoid.push_back (Offset (xe.center (), ye[dir_]));
 618         }
 619     }
 620   return avoid;
 621 }
 622
 623 void
 624 Slur_score_state::generate_curves () const
 625 {
 626   Real r_0 = robust_scm2double (slur_->get_property ("ratio"), 0.33);
 627   Real h_inf = staff_space_ * scm_to_double (slur_->get_property ("height-limit"));
 628
 629   vector<Offset> avoid = generate_avoid_offsets ();
 630   for (vsize i = 0; i < configurations_.size (); i++)
 631     configurations_[i]->generate_curve (*this, r_0, h_inf, avoid);
 632 }
 633
 634 vector<Slur_configuration*>
 635 Slur_score_state::enumerate_attachments (Drul_array<Real> end_ys) const
 636 {
 637   vector<Slur_configuration*> scores;
 638
 639   Drul_array<Offset> os;
 640   os[LEFT] = base_attachments_[LEFT];
 641   Real minimum_length = staff_space_
 642     * robust_scm2double (slur_->get_property ("minimum-length"), 2.0);
 643
 644   for (int i = 0; dir_ * os[LEFT][Y_AXIS] <= dir_ * end_ys[LEFT]; i++)
 645     {
 646       os[RIGHT] = base_attachments_[RIGHT];
 647       for (int j = 0; dir_ * os[RIGHT][Y_AXIS] <= dir_ * end_ys[RIGHT]; j++)
 648         {
 649           Direction d = LEFT;
 650           Drul_array<bool> attach_to_stem (false, false);
 651           do
 652             {
 653               os[d][X_AXIS] = base_attachments_[d][X_AXIS];
 654               if (extremes_[d].stem_
 655                   && !Stem::is_invisible (extremes_[d].stem_)
 656                   && extremes_[d].stem_dir_ == dir_)
 657                 {
 658                   Interval stem_y = extremes_[d].stem_extent_[Y_AXIS];
 659                   stem_y.widen (0.25 * staff_space_);
 660                   if (stem_y.contains (os[d][Y_AXIS]))
 661                     {
 662                       os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS][-d]
 663                         - d * 0.3;
 664                       attach_to_stem[d] = true;
 665                     }
 666                   else if (dir_ * extremes_[d].stem_extent_[Y_AXIS][dir_]
 667                            < dir_ * os[d][Y_AXIS]
 668                            && !extremes_[d].stem_extent_[X_AXIS].is_empty ())
 669
 670                     os[d][X_AXIS] = extremes_[d].stem_extent_[X_AXIS].center ();
 671                 }
 672             }
 673           while (flip (&d) != LEFT);
 674
 675           Offset dz;
 676           dz = os[RIGHT] - os[LEFT];
 677           if (dz[X_AXIS] < minimum_length
 678               || fabs (dz[Y_AXIS] / dz[X_AXIS]) > parameters_.max_slope_)
 679             {
 680               do
 681                 {
 682                   if (extremes_[d].slur_head_
 683                       && !extremes_[d].slur_head_x_extent_.is_empty ())
 684                     {
 685                       os[d][X_AXIS] = extremes_[d].slur_head_x_extent_.center ();
 686                       attach_to_stem[d] = false;
 687                     }
 688                 }
 689               while (flip (&d) != LEFT);
 690             }
 691
 692           dz = os[RIGHT] - os[LEFT];
 693           do
 694             {
 695               if (extremes_[d].slur_head_
 696                   && !attach_to_stem[d])
 697                 {
 698                   /* Horizontally move tilted slurs a little.  Move
 699                      more for bigger tilts.
 700
 701                      TODO: parameter */
 702                   os[d][X_AXIS]
 703                     -= dir_ * extremes_[d].slur_head_x_extent_.length ()
 704                     * sin (dz.arg ()) / 3;
 705                 }
 706             }
 707           while (flip (&d) != LEFT);
 708
 709           scores.push_back (Slur_configuration::new_config (os, scores.size ()));
 710
 711           os[RIGHT][Y_AXIS] += dir_ * staff_space_ / 2;
 712         }
 713
 714       os[LEFT][Y_AXIS] += dir_ * staff_space_ / 2;
 715     }
 716
 717   assert (scores.size () > 0);
 718   return scores;
 719 }
 720
 721 vector<Extra_collision_info>
 722 Slur_score_state::get_extra_encompass_infos () const
 723 {
 724   extract_grob_set (slur_, "encompass-objects", encompasses);
 725   vector<Extra_collision_info> collision_infos;
 726   for (vsize i = encompasses.size (); i--;)
 727     {
 728       if (Slur::has_interface (encompasses[i]))
 729         {
 730           Spanner *small_slur = dynamic_cast<Spanner *> (encompasses[i]);
 731           Bezier b = Slur::get_curve (small_slur);
 732
 733           Offset relative (small_slur->relative_coordinate (common_[X_AXIS], X_AXIS),
 734                            small_slur->relative_coordinate (common_[Y_AXIS], Y_AXIS));
 735
 736           for (int k = 0; k < 3; k++)
 737             {
 738               Direction hdir = Direction (k - 1);
 739
 740               /*
 741                 Only take bound into account if small slur starts
 742                 together with big slur.
 743               */
 744               if (hdir && small_slur->get_bound (hdir) != slur_->get_bound (hdir))
 745                 continue;
 746
 747               Offset z = b.curve_point (k / 2.0);
 748               z += relative;
 749
 750               Interval yext;
 751               yext.set_full ();
 752               yext[dir_] = z[Y_AXIS] + dir_ * thickness_ * 1.0;
 753
 754               Interval xext (-1, 1);
 755               xext = xext * (thickness_ * 2) + z[X_AXIS];
 756               Extra_collision_info info (small_slur,
 757                                          hdir,
 758                                          xext,
 759                                          yext,
 760                                          parameters_.extra_object_collision_penalty_);
 761               collision_infos.push_back (info);
 762             }
 763         }
 764       else
 765         {
 766           Grob *g = encompasses [i];
 767           Interval xe = g->extent (common_[X_AXIS], X_AXIS);
 768           Interval ye = g->extent (common_[Y_AXIS], Y_AXIS);
 769
 770           Real xp = 0.0;
 771           Real penalty = parameters_.extra_object_collision_penalty_;
 772           if (Accidental_interface::has_interface (g))
 773             {
 774               penalty = parameters_.accidental_collision_;
 775
 776               Rational alt = ly_scm2rational (g->get_property ("alteration"));
 777               SCM scm_style = g->get_property ("style");
 778               if (!scm_is_symbol (scm_style)
 779                   && !to_boolean (g->get_property ("parenthesized"))
 780                   && !to_boolean (g->get_property ("restore-first")))
 781                 {
 782                   /* End copy accidental.cc */
 783                   if (alt == FLAT_ALTERATION
 784                       || alt == DOUBLE_FLAT_ALTERATION)
 785                     xp = LEFT;
 786                   else if (alt == SHARP_ALTERATION)
 787                     xp = 0.5 * dir_;
 788                   else if (alt == NATURAL_ALTERATION)
 789                     xp = -dir_;
 790                 }
 791             }
 792
 793           ye.widen (thickness_ * 0.5);
 794           xe.widen (thickness_ * 1.0);
 795           Extra_collision_info info (g, xp, xe, ye, penalty);
 796           collision_infos.push_back (info);
 797         }
 798     }
 799
 800   return collision_infos;
 801 }
 802
 803 Extra_collision_info::Extra_collision_info (Grob *g, Real idx, Interval x, Interval y, Real p)
 804 {
 805   idx_ = idx;
 806   extents_[X_AXIS] = x;
 807   extents_[Y_AXIS] = y;
 808   penalty_ = p;
 809   grob_ = g;
 810   type_ = g->get_property ("avoid-slur");
 811 }
 812
 813 Extra_collision_info::Extra_collision_info ()
 814 {
 815   idx_ = 0.0;
 816   penalty_ = 0.;
 817   grob_ = 0;
 818   type_ = SCM_EOL;
 819 }