lily/system.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
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "system.hh"
  21
  22 #include "align-interface.hh"
  23 #include "all-font-metrics.hh"
  24 #include "axis-group-interface.hh"
  25 #include "break-align-interface.hh"
  26 #include "grob-array.hh"
  27 #include "hara-kiri-group-spanner.hh"
  28 #include "international.hh"
  29 #include "lookup.hh"
  30 #include "main.hh"
  31 #include "output-def.hh"
  32 #include "page-layout-problem.hh"
  33 #include "paper-column.hh"
  34 #include "paper-score.hh"
  35 #include "paper-system.hh"
  36 #include "pointer-group-interface.hh"
  37 #include "skyline-pair.hh"
  38 #include "staff-symbol-referencer.hh"
  39 #include "text-interface.hh"
  40 #include "warn.hh"
  41
  42 System::System (System const &src)
  43   : Spanner (src)
  44 {
  45   all_elements_ = 0;
  46   pscore_ = 0;
  47   rank_ = 0;
  48   checked_footnotes_ = false;
  49   init_elements ();
  50 }
  51
  52 System::System (SCM s)
  53   : Spanner (s)
  54 {
  55   all_elements_ = 0;
  56   rank_ = 0;
  57   checked_footnotes_ = false;
  58   init_elements ();
  59 }
  60
  61 void
  62 System::init_elements ()
  63 {
  64   SCM scm_arr = Grob_array::make_array ();
  65   all_elements_ = unsmob_grob_array (scm_arr);
  66   all_elements_->set_ordered (false);
  67   set_object ("all-elements", scm_arr);
  68 }
  69
  70 Grob *
  71 System::clone () const
  72 {
  73   return new System (*this);
  74 }
  75
  76 int
  77 System::element_count () const
  78 {
  79   return all_elements_->size ();
  80 }
  81
  82 int
  83 System::spanner_count () const
  84 {
  85   int k = 0;
  86   for (vsize i = all_elements_->size (); i--;)
  87     if (dynamic_cast<Spanner *> (all_elements_->grob (i)))
  88       k++;
  89   return k;
  90 }
  91
  92 void
  93 System::typeset_grob (Grob *elem)
  94 {
  95   if (elem->layout_)
  96     programming_error ("adding element twice");
  97   else
  98     {
  99       elem->layout_ = pscore_->layout ();
 100       all_elements_->add (elem);
 101       elem->unprotect ();
 102     }
 103 }
 104
 105 void
 106 System::derived_mark () const
 107 {
 108   if (!all_elements_->empty ())
 109     {
 110       Grob **ptr = &all_elements_->array_reference ()[0];
 111       Grob **end = ptr + all_elements_->size ();
 112       while (ptr < end)
 113         {
 114           scm_gc_mark ((*ptr)->self_scm ());
 115           ptr++;
 116         }
 117     }
 118
 119   if (pscore_)
 120     scm_gc_mark (pscore_->self_scm ());
 121
 122   Spanner::derived_mark ();
 123 }
 124
 125 static void
 126 fixup_refpoints (vector<Grob *> const &grobs)
 127 {
 128   for (vsize i = grobs.size (); i--;)
 129     grobs[i]->fixup_refpoint ();
 130 }
 131
 132 void
 133 System::do_break_substitution_and_fixup_refpoints ()
 134 {
 135   for (vsize i = 0; i < all_elements_->size (); i++)
 136     {
 137       Grob *g = all_elements_->grob (i);
 138       if (g->internal_has_interface (ly_symbol2scm ("only-prebreak-interface")))
 139         {
 140           /*
 141             Kill no longer needed grobs.
 142           */
 143           Item *it = dynamic_cast<Item *> (g);
 144           if (it && Item::is_non_musical (it))
 145             {
 146               it->find_prebroken_piece (LEFT)->suicide ();
 147               it->find_prebroken_piece (RIGHT)->suicide ();
 148             }
 149           g->suicide ();
 150         }
 151       else if (g->is_live ())
 152         g->do_break_processing ();
 153     }
 154
 155   /*
 156     fixups must be done in broken line_of_scores, because new elements
 157     are put over there.  */
 158   int count = 0;
 159   for (vsize i = 0; i < broken_intos_.size (); i++)
 160     {
 161       Grob *se = broken_intos_[i];
 162
 163       extract_grob_set (se, "all-elements", all_elts);
 164       for (vsize j = 0; j < all_elts.size (); j++)
 165         {
 166           Grob *g = all_elts[j];
 167           g->fixup_refpoint ();
 168         }
 169
 170       count += all_elts.size ();
 171     }
 172
 173   /*
 174     needed for doing items.
 175   */
 176   fixup_refpoints (all_elements_->array ());
 177
 178   for (vsize i = 0; i < all_elements_->size (); i++)
 179     all_elements_->grob (i)->handle_broken_dependencies ();
 180
 181   handle_broken_dependencies ();
 182
 183   /* Because the this->get_property (all-elements) contains items in 3
 184      versions, handle_broken_dependencies () will leave duplicated
 185      items in all-elements.  Strictly speaking this is harmless, but
 186      it leads to duplicated symbols in the output.  uniq makes sure
 187      that no duplicates are in the list.  */
 188   for (vsize i = 0; i < broken_intos_.size (); i++)
 189     {
 190       System *child = dynamic_cast<System *> (broken_intos_[i]);
 191       child->all_elements_->remove_duplicates ();
 192       for (vsize j = 0; j < child->all_elements_->size (); j++)
 193         {
 194           Grob *g = child->all_elements_->grob (j);
 195
 196           (void) g->get_property ("after-line-breaking");
 197         }
 198     }
 199
 200   if (be_verbose_global)
 201     message (_f ("Element count %d", count + element_count ()) + "\n");
 202 }
 203
 204 SCM
 205 System::get_broken_system_grobs ()
 206 {
 207   SCM ret = SCM_EOL;
 208   for (vsize i = 0; i < broken_intos_.size (); i++)
 209     ret = scm_cons (broken_intos_[i]->self_scm (), ret);
 210   return scm_reverse (ret);
 211 }
 212
 213 SCM
 214 System::get_paper_systems ()
 215 {
 216   SCM lines = scm_c_make_vector (broken_intos_.size (), SCM_EOL);
 217   for (vsize i = 0; i < broken_intos_.size (); i++)
 218     {
 219       if (be_verbose_global)
 220         progress_indication ("[");
 221
 222       System *system = dynamic_cast<System *> (broken_intos_[i]);
 223
 224       scm_vector_set_x (lines, scm_from_int (i),
 225                         system->get_paper_system ());
 226
 227       if (be_verbose_global)
 228         progress_indication (to_string (i) + "]");
 229     }
 230   return lines;
 231 }
 232
 233 void
 234 System::populate_footnote_grob_vector ()
 235 {
 236   extract_grob_set (this, "all-elements", all_elts);
 237   for (vsize i = 0; i < all_elts.size (); i++)
 238     if (all_elts[i]->internal_has_interface (ly_symbol2scm ("footnote-interface")))
 239       footnote_grobs_.push_back (all_elts[i]);
 240
 241   sort (footnote_grobs_.begin (), footnote_grobs_.end (), Grob::less);
 242   checked_footnotes_ = true;
 243 }
 244
 245 void
 246 System::get_footnote_grobs_in_range (vector<Grob *> &out, vsize start, vsize end)
 247 {
 248   if (!checked_footnotes_)
 249     populate_footnote_grob_vector ();
 250
 251   for (vsize i = 0; i < footnote_grobs_.size (); i++)
 252     {
 253       int pos = footnote_grobs_[i]->spanned_rank_interval ()[LEFT];
 254       bool end_of_line_visible = true;
 255       if (Spanner *s = dynamic_cast<Spanner *>(footnote_grobs_[i]))
 256         {
 257           Direction spanner_placement =  robust_scm2dir (s->get_property ("spanner-placement"), LEFT);
 258           if (spanner_placement == CENTER)
 259             spanner_placement = LEFT;
 260
 261           pos = s->spanned_rank_interval ()[spanner_placement];
 262         }
 263
 264       if (Item *item = dynamic_cast<Item *>(footnote_grobs_[i]))
 265         {
 266           if (!Item::break_visible (item))
 267             continue;
 268           // safeguard to bring down the column rank so that end of line footnotes show up on the correct line
 269           end_of_line_visible = (LEFT == item->break_status_dir ());
 270         }
 271
 272       if (pos < int (start))
 273         continue;
 274       if (pos > int (end))
 275         break;
 276       if (pos == int (start) && end_of_line_visible)
 277         continue;
 278       if (pos == int (end) && !end_of_line_visible)
 279         continue;
 280       if (!footnote_grobs_[i]->is_live ())
 281         continue;
 282
 283       out.push_back (footnote_grobs_[i]);
 284     }
 285 }
 286
 287 vector<Stencil *>
 288 System::get_footnotes_in_range (vsize start, vsize end)
 289 {
 290   vector<Grob *> footnote_grobs;
 291   get_footnote_grobs_in_range (footnote_grobs, start, end);
 292   vector<Stencil *> out;
 293
 294   for (vsize i = 0; i < footnote_grobs.size (); i++)
 295     {
 296       SCM footnote_markup = footnote_grobs[i]->get_property ("footnote-text");
 297
 298       if (!Text_interface::is_markup (footnote_markup))
 299         continue;
 300
 301       SCM props = scm_call_1 (ly_lily_module_constant ("layout-extract-page-properties"),
 302                               pscore_->layout ()->self_scm ());
 303
 304       SCM footnote_stl = Text_interface::interpret_markup (pscore_->layout ()->self_scm (),
 305                                                            props, footnote_markup);
 306
 307       Stencil *footnote_stencil = unsmob_stencil (footnote_stl);
 308       out.push_back (footnote_stencil);
 309     }
 310
 311   return out;
 312 }
 313
 314 Stencil
 315 System::make_footnote_stencil (Real padding)
 316 {
 317   Stencil mol;
 318
 319   for (vsize i = 0; i < footnote_grobs_.size (); i++)
 320     {
 321       SCM footnote_markup = footnote_grobs_[i]->get_property ("footnote-text");
 322       if (Spanner *orig = dynamic_cast<Spanner *>(footnote_grobs_[i]))
 323         if (orig->is_broken ())
 324           footnote_markup = orig->broken_intos_[0]->get_property ("footnote-text");
 325
 326       if (!Text_interface::is_markup (footnote_markup))
 327         continue;
 328
 329       SCM props = scm_call_1 (ly_lily_module_constant ("layout-extract-page-properties"),
 330                               pscore_->layout ()->self_scm ());
 331
 332       SCM footnote_stl = Text_interface::interpret_markup (pscore_->layout ()->self_scm (),
 333                                                            props, footnote_markup);
 334
 335       mol.add_at_edge (Y_AXIS, DOWN, *unsmob_stencil (footnote_stl), padding);
 336     }
 337
 338   return mol;
 339 }
 340
 341 void
 342 System::break_into_pieces (vector<Column_x_positions> const &breaking)
 343 {
 344   for (vsize i = 0; i < breaking.size (); i++)
 345     {
 346       System *system = dynamic_cast<System *> (clone ());
 347       system->rank_ = broken_intos_.size ();
 348
 349       vector<Grob *> c (breaking[i].cols_);
 350       pscore_->typeset_system (system);
 351
 352       int st = Paper_column::get_rank (c[0]);
 353       int end = Paper_column::get_rank (c.back ());
 354       Interval iv (pure_height (this, st, end));
 355       system->set_property ("pure-Y-extent", ly_interval2scm (iv));
 356
 357       get_footnote_grobs_in_range (system->footnote_grobs_, st, end);
 358
 359       system->set_bound (LEFT, c[0]);
 360       system->set_bound (RIGHT, c.back ());
 361       SCM system_labels = SCM_EOL;
 362       for (vsize j = 0; j < c.size (); j++)
 363         {
 364           c[j]->translate_axis (breaking[i].config_[j], X_AXIS);
 365           dynamic_cast<Paper_column *> (c[j])->set_system (system);
 366           /* collect the column labels */
 367           collect_labels (c[j], &system_labels);
 368         }
 369       /*
 370         Collect labels from any loose columns too: theses will be set on
 371         an empty bar line or a column which is otherwise unused mid-line
 372       */
 373       vector<Grob *> loose (breaking[i].loose_cols_);
 374       for (vsize j = 0; j < loose.size (); j++)
 375         collect_labels (loose[j], &system_labels);
 376
 377       system->set_property ("labels", system_labels);
 378
 379       set_loose_columns (system, &breaking[i]);
 380       broken_intos_.push_back (system);
 381     }
 382 }
 383
 384 void
 385 System::collect_labels (Grob const *col, SCM *labels)
 386 {
 387   SCM col_labels = col->get_property ("labels");
 388   if (scm_is_pair (col_labels))
 389     *labels = scm_append (scm_list_2 (col_labels, *labels));
 390 }
 391
 392 void
 393 System::add_column (Paper_column *p)
 394 {
 395   Grob *me = this;
 396   Grob_array *ga = unsmob_grob_array (me->get_object ("columns"));
 397   if (!ga)
 398     {
 399       SCM scm_ga = Grob_array::make_array ();
 400       me->set_object ("columns", scm_ga);
 401       ga = unsmob_grob_array (scm_ga);
 402     }
 403
 404   p->set_rank (ga->size ());
 405
 406   ga->add (p);
 407   Axis_group_interface::add_element (this, p);
 408 }
 409
 410 void
 411 System::pre_processing ()
 412 {
 413   for (vsize i = 0; i < all_elements_->size (); i++)
 414     all_elements_->grob (i)->discretionary_processing ();
 415
 416   if (be_verbose_global)
 417     message (_f ("Grob count %d", element_count ()));
 418
 419   /*
 420     order is significant: broken grobs are added to the end of the
 421     array, and should be processed before the original is potentially
 422     killed.
 423   */
 424   for (vsize i = all_elements_->size (); i--;)
 425     all_elements_->grob (i)->handle_prebroken_dependencies ();
 426
 427   fixup_refpoints (all_elements_->array ());
 428
 429   for (vsize i = 0; i < all_elements_->size (); i++)
 430     {
 431       Grob *g = all_elements_->grob (i);
 432       (void) g->get_property ("before-line-breaking");
 433     }
 434
 435   for (vsize i = 0; i < all_elements_->size (); i++)
 436     {
 437       Grob *e = all_elements_->grob (i);
 438       (void) e->get_property ("springs-and-rods");
 439     }
 440 }
 441
 442 void
 443 System::post_processing ()
 444 {
 445   Interval iv (extent (this, Y_AXIS));
 446   if (iv.is_empty ())
 447     programming_error ("system with empty extent");
 448   else
 449     translate_axis (-iv[MAX], Y_AXIS);
 450
 451   /* Generate all stencils to trigger font loads.
 452      This might seem inefficient, but Stencils are cached per grob
 453      anyway. */
 454
 455   vector<Grob *> all_elts_sorted (all_elements_->array ());
 456   vector_sort (all_elts_sorted, std::less<Grob *> ());
 457   uniq (all_elts_sorted);
 458   this->get_stencil ();
 459   for (vsize i = all_elts_sorted.size (); i--;)
 460     {
 461       Grob *g = all_elts_sorted[i];
 462       g->get_stencil ();
 463     }
 464 }
 465
 466 struct Layer_entry
 467 {
 468   Grob *grob_;
 469   int layer_;
 470 };
 471
 472 bool
 473 operator< (Layer_entry  const &a,
 474            Layer_entry  const &b)
 475 {
 476   return a.layer_ < b.layer_;
 477 }
 478
 479 SCM
 480 System::get_paper_system ()
 481 {
 482   SCM exprs = SCM_EOL;
 483   SCM *tail = &exprs;
 484
 485   post_processing ();
 486
 487   vector<Layer_entry> entries;
 488   for (vsize j = 0; j < all_elements_->size (); j++)
 489     {
 490       Layer_entry e;
 491       e.grob_ = all_elements_->grob (j);
 492       e.layer_ = robust_scm2int (e.grob_->get_property ("layer"), 1);
 493
 494       entries.push_back (e);
 495     }
 496
 497   vector_sort (entries, std::less<Layer_entry> ());
 498   for (vsize j = 0; j < entries.size (); j++)
 499     {
 500       Grob *g = entries[j].grob_;
 501       Stencil st = g->get_print_stencil ();
 502
 503       if (st.expr () == SCM_EOL)
 504         continue;
 505
 506       Offset o;
 507       for (int a = X_AXIS; a < NO_AXES; a++)
 508         o[Axis (a)] = g->relative_coordinate (this, Axis (a));
 509
 510       Offset extra = robust_scm2offset (g->get_property ("extra-offset"),
 511                                         Offset (0, 0))
 512         * Staff_symbol_referencer::staff_space (g);
 513
 514       /* Must copy the stencil, for we cannot change the stencil
 515          cached in G.  */
 516
 517       st.translate (o + extra);
 518
 519       *tail = scm_cons (st.expr (), SCM_EOL);
 520       tail = SCM_CDRLOC (*tail);
 521     }
 522
 523   if (Stencil *me = get_stencil ())
 524     exprs = scm_cons (me->expr (), exprs);
 525
 526   Interval x (extent (this, X_AXIS));
 527   Interval y (extent (this, Y_AXIS));
 528   Stencil sys_stencil (Box (x, y),
 529                        scm_cons (ly_symbol2scm ("combine-stencil"),
 530                                  exprs));
 531   if (debug_skylines)
 532     {
 533       Skyline_pair *skylines = Skyline_pair::unsmob (get_property ("vertical-skylines"));
 534       if (skylines)
 535         {
 536           Stencil up
 537             = Lookup::points_to_line_stencil (0.1, (*skylines)[UP].to_points (X_AXIS));
 538           Stencil down
 539             = Lookup::points_to_line_stencil (0.1, (*skylines)[DOWN].to_points (X_AXIS));
 540           sys_stencil.add_stencil (up.in_color (255, 0, 0));
 541           sys_stencil.add_stencil (down.in_color (0, 255, 0));
 542         }
 543     }
 544
 545   Grob *left_bound = this->get_bound (LEFT);
 546   SCM prop_init = left_bound->get_property ("line-break-system-details");
 547   Prob *pl = make_paper_system (prop_init);
 548   paper_system_set_stencil (pl, sys_stencil);
 549
 550   /* information that the page breaker might need */
 551   Grob *right_bound = this->get_bound (RIGHT);
 552   pl->set_property ("vertical-skylines", this->get_property ("vertical-skylines"));
 553   pl->set_property ("page-break-permission", right_bound->get_property ("page-break-permission"));
 554   pl->set_property ("page-turn-permission", right_bound->get_property ("page-turn-permission"));
 555   pl->set_property ("page-break-penalty", right_bound->get_property ("page-break-penalty"));
 556   pl->set_property ("page-turn-penalty", right_bound->get_property ("page-turn-penalty"));
 557
 558   Interval staff_refpoints;
 559   if (Grob *align = get_vertical_alignment ())
 560     {
 561       extract_grob_set (align, "elements", staves);
 562       for (vsize i = 0; i < staves.size (); i++)
 563         if (staves[i]->is_live ()
 564             && Page_layout_problem::is_spaceable (staves[i]))
 565           staff_refpoints.add_point (staves[i]->relative_coordinate (this,
 566                                                                      Y_AXIS));
 567     }
 568
 569   pl->set_property ("staff-refpoint-extent", ly_interval2scm (staff_refpoints));
 570   pl->set_property ("system-grob", this->self_scm ());
 571
 572   return pl->unprotect ();
 573 }
 574
 575 vector<Item *>
 576 System::broken_col_range (Item const *left, Item const *right) const
 577 {
 578   vector<Item *> ret;
 579
 580   left = left->get_column ();
 581   right = right->get_column ();
 582
 583   extract_grob_set (this, "columns", cols);
 584
 585   vsize i = Paper_column::get_rank (left);
 586   int end_rank = Paper_column::get_rank (right);
 587   if (i < cols.size ())
 588     i++;
 589
 590   while (i < cols.size ()
 591          && Paper_column::get_rank (cols[i]) < end_rank)
 592     {
 593       Paper_column *c = dynamic_cast<Paper_column *> (cols[i]);
 594       if (Paper_column::is_breakable (c) && !c->get_system ())
 595         ret.push_back (c);
 596       i++;
 597     }
 598
 599   return ret;
 600 }
 601
 602 /** Return all columns, but filter out any unused columns , since they might
 603     disrupt the spacing problem. */
 604 vector<Grob *>
 605 System::used_columns () const
 606 {
 607   extract_grob_set (this, "columns", ro_columns);
 608
 609   int last_breakable = ro_columns.size ();
 610
 611   while (last_breakable--)
 612     {
 613       if (Paper_column::is_breakable (ro_columns [last_breakable]))
 614         break;
 615     }
 616
 617   vector<Grob *> columns;
 618   for (int i = 0; i <= last_breakable; i++)
 619     {
 620       if (Paper_column::is_used (ro_columns[i]))
 621         columns.push_back (ro_columns[i]);
 622     }
 623
 624   return columns;
 625 }
 626
 627 Paper_column *
 628 System::column (vsize which) const
 629 {
 630   extract_grob_set (this, "columns", columns);
 631   if (which >= columns.size ())
 632     return 0;
 633
 634   return dynamic_cast<Paper_column *> (columns[which]);
 635 }
 636
 637 Paper_score *
 638 System::paper_score () const
 639 {
 640   return pscore_;
 641 }
 642
 643 int
 644 System::get_rank () const
 645 {
 646   return rank_;
 647 }
 648
 649 System *
 650 get_root_system (Grob *me)
 651 {
 652   Grob *system_grob = me;
 653
 654   while (system_grob->get_parent (Y_AXIS))
 655     system_grob = system_grob->get_parent (Y_AXIS);
 656
 657   return dynamic_cast<System *> (system_grob);
 658 }
 659
 660 Grob *
 661 System::get_vertical_alignment ()
 662 {
 663   extract_grob_set (this, "elements", elts);
 664   Grob *ret = 0;
 665   for (vsize i = 0; i < elts.size (); i++)
 666     if (Align_interface::has_interface (elts[i]))
 667       {
 668         if (ret)
 669           programming_error ("found multiple vertical alignments in this system");
 670         ret = elts[i];
 671       }
 672
 673   if (!ret)
 674     programming_error ("didn't find a vertical alignment in this system");
 675   return ret;
 676 }
 677
 678 // Finds the furthest staff in the given direction whose x-extent
 679 // overlaps with the given interval.
 680 Grob *
 681 System::get_extremal_staff (Direction dir, Interval const &iv)
 682 {
 683   Grob *align = get_vertical_alignment ();
 684   if (!align)
 685     return 0;
 686
 687   extract_grob_set (align, "elements", elts);
 688   vsize start = (dir == UP) ? 0 : elts.size () - 1;
 689   vsize end = (dir == UP) ? elts.size () : VPOS;
 690   for (vsize i = start; i != end; i += dir)
 691     {
 692       if (Hara_kiri_group_spanner::has_interface (elts[i]))
 693         Hara_kiri_group_spanner::consider_suicide (elts[i]);
 694
 695       Interval intersection = elts[i]->extent (this, X_AXIS);
 696       intersection.intersect (iv);
 697       if (elts[i]->is_live () && !intersection.is_empty ())
 698         return elts[i];
 699     }
 700   return 0;
 701 }
 702
 703 Interval
 704 System::pure_refpoint_extent (vsize start, vsize end)
 705 {
 706   Interval ret;
 707   Grob *alignment = get_vertical_alignment ();
 708   if (!alignment)
 709     return Interval ();
 710
 711   extract_grob_set (alignment, "elements", staves);
 712   vector<Real> offsets = Align_interface::get_pure_minimum_translations (alignment, staves, Y_AXIS, start, end);
 713
 714   for (vsize i = 0; i < offsets.size (); ++i)
 715     if (Page_layout_problem::is_spaceable (staves[i]))
 716       {
 717         ret[UP] = offsets[i];
 718         break;
 719       }
 720
 721   for (vsize i = offsets.size (); i--;)
 722     if (Page_layout_problem::is_spaceable (staves[i]))
 723       {
 724         ret[DOWN] = offsets[i];
 725         break;
 726       }
 727
 728   return ret;
 729 }
 730
 731 Interval
 732 System::part_of_line_pure_height (vsize start, vsize end, bool begin)
 733 {
 734   Grob *alignment = get_vertical_alignment ();
 735   if (!alignment)
 736     return Interval ();
 737
 738   extract_grob_set (alignment, "elements", staves);
 739   vector<Real> offsets = Align_interface::get_pure_minimum_translations (alignment, staves, Y_AXIS, start, end);
 740
 741   Interval ret;
 742   for (vsize i = 0; i < staves.size (); ++i)
 743     {
 744       Interval iv = begin
 745         ? Axis_group_interface::begin_of_line_pure_height (staves[i], start)
 746         : Axis_group_interface::rest_of_line_pure_height (staves[i], start, end);
 747       if (i < offsets.size ())
 748         iv.translate (offsets[i]);
 749       ret.unite (iv);
 750     }
 751
 752   Interval other_elements = begin
 753     ? Axis_group_interface::begin_of_line_pure_height (this, start)
 754     : Axis_group_interface::rest_of_line_pure_height (this, start, end);
 755
 756   ret.unite (other_elements);
 757
 758   return ret;
 759 }
 760
 761 Interval
 762 System::begin_of_line_pure_height (vsize start, vsize end)
 763 {
 764   return part_of_line_pure_height (start, end, true);
 765 }
 766
 767 Interval
 768 System::rest_of_line_pure_height (vsize start, vsize end)
 769 {
 770   return part_of_line_pure_height (start, end, false);
 771 }
 772
 773 // This differs from Axis_group_interface::calc_pure_relevant_grobs
 774 // because here, we are only interested in those few elements that aren't
 775 // descended from VerticalAlignment (ie. things like RehearsalMark, BarLine).
 776 MAKE_SCHEME_CALLBACK (System, calc_pure_relevant_grobs, 1);
 777 SCM
 778 System::calc_pure_relevant_grobs (SCM smob)
 779 {
 780   Grob *me = unsmob_grob (smob);
 781
 782   extract_grob_set (me, "elements", elts);
 783   vector<Grob *> relevant_grobs;
 784   SCM pure_relevant_p = ly_lily_module_constant ("pure-relevant?");
 785
 786   for (vsize i = 0; i < elts.size (); ++i)
 787     {
 788       if (!Axis_group_interface::has_interface (elts[i]))
 789         {
 790           if (to_boolean (scm_apply_1 (pure_relevant_p, elts[i]->self_scm (), SCM_EOL)))
 791             relevant_grobs.push_back (elts[i]);
 792
 793           if (Item *it = dynamic_cast<Item*> (elts[i]))
 794             {
 795               Direction d = LEFT;
 796               do
 797                 {
 798                   Item *piece = it->find_prebroken_piece (d);
 799                   if (piece && to_boolean (scm_apply_1 (pure_relevant_p, piece->self_scm (), SCM_EOL)))
 800                     relevant_grobs.push_back (piece);
 801                 }
 802               while (flip (&d) != LEFT);
 803             }
 804         }
 805     }
 806
 807   SCM grobs_scm = Grob_array::make_array ();
 808
 809   unsmob_grob_array (grobs_scm)->set_array (relevant_grobs);
 810   return grobs_scm;
 811 }
 812
 813 MAKE_SCHEME_CALLBACK (System, height, 1);
 814 SCM
 815 System::height (SCM smob)
 816 {
 817   return Axis_group_interface::height (smob);
 818 }
 819
 820 MAKE_SCHEME_CALLBACK (System, calc_pure_height, 3);
 821 SCM
 822 System::calc_pure_height (SCM smob, SCM start_scm, SCM end_scm)
 823 {
 824   System *me = dynamic_cast<System *> (unsmob_grob (smob));
 825   int start = scm_to_int (start_scm);
 826   int end = scm_to_int (end_scm);
 827
 828   Interval begin = me->begin_of_line_pure_height (start, end);
 829   Interval rest = me->rest_of_line_pure_height (start, end);
 830   begin.unite (rest);
 831
 832   return ly_interval2scm (begin);
 833 }
 834
 835 Grob*
 836 System::get_pure_bound (Direction d, int start, int end)
 837 {
 838   vector<vsize> ranks = pscore_->get_break_ranks ();
 839   vector<vsize> indices = pscore_->get_break_indices ();
 840   vector<Grob*> cols = pscore_->get_columns ();
 841
 842   vsize target_rank = (d == LEFT ? start : end);
 843   vector<vsize>::const_iterator i =
 844     lower_bound (ranks.begin (), ranks.end (), target_rank, std::less<vsize> ());
 845
 846   if (i != ranks.end () && (*i) == target_rank)
 847     return cols[indices[i - ranks.begin ()]];
 848   else
 849     return 0;
 850 }
 851
 852 Grob*
 853 System::get_maybe_pure_bound (Direction d, bool pure, int start, int end)
 854 {
 855   return pure ? get_pure_bound (d, start, end) : get_bound (d);
 856 }
 857
 858 ADD_INTERFACE (System,
 859                "This is the top-level object: Each object in a score"
 860                " ultimately has a @code{System} object as its X and"
 861                " Y@tie{}parent.",
 862
 863                /* properties */
 864                "all-elements "
 865                "columns "
 866                "labels "
 867                "pure-Y-extent "
 868                "skyline-horizontal-padding "
 869                );