2 This file is part of LilyPond, the GNU music typesetter.
4 Copyright (C) 2006--2015 Joe Neeman <joeneeman@gmail.com>
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.
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.
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/>.
20 #include "constrained-breaking.hh"
22 #include "international.hh"
24 #include "output-def.hh"
25 #include "page-layout-problem.hh"
26 #include "paper-column.hh"
27 #include "paper-score.hh"
28 #include "simple-spacer.hh"
35 We use the following optimal substructure. Let W (A) be our weight function.
37 Let A_{k, n} = (a_{k, n, 1}, ... a_{k, n, k}) be the optimal set of line breaks
38 for k systems and n potential breakpoints. a_{k, n, k} = n (it is the end of
41 Then A_{k+1, m} is contructed from
42 min_ {k < j < m} ( W (A_{k, j} :: m) )
43 where by A::m we denote appending m to the list A
47 The above algorithm makes it easy to end at a point before the end of the
48 score (just find A_{k, m} for some m < breaks_.size () - 1). However, we must
49 add information for starting at a point after the beginning. One constructor
50 allows the specification of a list of starting columns, start_. We then have
51 start_.size () different solution arrays. state_[i] is the array for the
52 solution starting at column number start_[i].
54 The indices "start" and "end" refer to the index in the start_ array of the
55 desired starting and ending columns.
57 each solution array looks like
58 a_{1,1,1} a_{2,1,2} a_{3,1,3} . . .
59 X a_{2,2,2} a_{3,2,3} . . .
63 where the X's mark invalid solutions (can't have more systems than
64 breakpoints). Note that each value is of the form a_{x, n, x}. This is because
65 a breakpoint of the form a_{x, n, x-1} will also be called a_{x-1, m, x-1} for
66 some m < n. Each cell in the array stores the value of its m (ie. the
67 ending breakpoint of the previous line) as "prev_".
69 For finding A_{sys, brk}, let "me" be the (sys_count, brk) cell in our
70 solution array (state_[start][sys * rank + brk]).
72 Then A_{sys, brk} = A_{sys - 1, me.prev_} :: me
76 start and sys here are indexed from 0.
77 brk is indexed from starting_breakpoints_[start]
78 (for brk, starting_breakpoints_[start] is the beginning
79 of the piece; the smallest value we should ever see here is
80 starting_breakpoints_[start] + 1) */
82 Constrained_breaking::calc_subproblem (vsize start, vsize sys, vsize brk)
84 assert (sys < systems_);
85 assert (start < start_.size ());
86 assert (brk < breaks_.size ());
88 bool found_something = false;
89 vsize start_col = starting_breakpoints_[start];
90 Matrix<Constrained_break_node> &st = state_[start];
91 vsize max_index = brk - start_col;
92 for (vsize j = max_index; j-- > sys;)
94 if (0 == sys && j > 0)
95 continue; /* the first line cannot have its first break after the beginning */
97 Line_details const &cur = lines_.at (brk, j + start_col);
98 if (isinf (cur.force_))
106 prev_f = st.at (j, sys - 1).details_.force_;
107 prev_dem = st.at (j, sys - 1).demerits_;
109 if (isinf (prev_dem))
112 Real dem = combine_demerits (cur.force_, prev_f) + prev_dem + cur.break_penalty_;
113 Constrained_break_node &n = st.at (max_index, sys);
114 if (dem < n.demerits_)
116 found_something = true;
122 return found_something;
126 Constrained_breaking::space_line (vsize i, vsize j)
128 bool ragged_right = to_boolean (pscore_->layout ()->c_variable ("ragged-right"));
129 bool ragged_last = to_boolean (pscore_->layout ()->c_variable ("ragged-last"));
131 vector<Grob *> line (all_.begin () + breaks_[i],
132 all_.begin () + breaks_[j] + 1);
133 Interval line_dims = line_dimensions_int (pscore_->layout (), i);
134 bool last = j == breaks_.size () - 1;
135 bool ragged = ragged_right || (last && ragged_last);
137 /* As a special case, if there is only one line in the score and ragged-right
138 hasn't been specifically forbidden and the line is stretched, use
141 && lines_.at (i, j).force_ >= 0
142 && !scm_is_bool (pscore_->layout ()->c_variable ("ragged-right"))
143 && !scm_is_bool (pscore_->layout ()->c_variable ("ragged-last")))
146 return get_line_configuration (line, line_dims[RIGHT] - line_dims[LEFT], line_dims[LEFT], ragged);
150 Constrained_breaking::resize (vsize systems)
154 if (pscore_ && systems_ > valid_systems_)
156 for (vsize i = 0; i < state_.size (); i++)
157 state_[i].resize (breaks_.size () - starting_breakpoints_[i], systems_, Constrained_break_node ());
159 /* fill out the matrices */
160 for (vsize i = 0; i < state_.size (); i++)
161 for (vsize j = valid_systems_; j < systems_; j++)
162 for (vsize k = starting_breakpoints_[i] + j + 1; k < breaks_.size (); k++)
163 if (!calc_subproblem (i, j, k))
164 break; /* if we couldn't break this, it is too cramped already */
165 valid_systems_ = systems_;
169 vector<Column_x_positions>
170 Constrained_breaking::solve (vsize start, vsize end, vsize sys_count)
172 vsize start_brk = starting_breakpoints_[start];
173 vsize end_brk = prepare_solution (start, end, sys_count);
175 Matrix<Constrained_break_node> const &st = state_[start];
176 vector<Column_x_positions> ret;
178 /* find the first solution that satisfies constraints */
179 for (vsize sys = sys_count - 1; sys != VPOS; sys--)
181 for (vsize brk = end_brk; brk != VPOS; brk--)
183 if (!isinf (st.at (brk, sys).details_.force_))
187 brk = st.at (brk, sys).prev_;
189 warning (_ ("cannot find line breaking that satisfies constraints"));
190 ret.push_back (space_line (brk, end_brk));
193 /* build up the good part of the solution */
194 for (vsize cur_sys = sys; cur_sys != VPOS; cur_sys--)
196 vsize prev_brk = st.at (brk, cur_sys).prev_;
197 assert (brk != VPOS);
198 ret.push_back (space_line (prev_brk + start_brk, brk + start_brk));
206 /* if we get to here, just put everything on one line */
208 warning (_ ("cannot find line breaking that satisfies constraints"));
209 ret.push_back (space_line (0, end_brk));
214 vector<Column_x_positions>
215 Constrained_breaking::best_solution (vsize start, vsize end)
217 vsize min_systems = min_system_count (start, end);
218 vsize max_systems = max_system_count (start, end);
219 Real best_demerits = infinity_f;
220 vector<Column_x_positions> best_so_far;
222 for (vsize i = min_systems; i <= max_systems; i++)
224 vsize brk = prepare_solution (start, end, i);
225 Real dem = state_[start].at (brk, i - 1).demerits_;
227 if (dem < best_demerits)
230 best_so_far = solve (start, end, i);
234 vector<Column_x_positions> cur = solve (start, end, i);
235 bool too_many_lines = true;
237 for (vsize j = 0; j < cur.size (); j++)
238 if (cur[j].force_ < 0)
240 too_many_lines = false;
247 if (best_so_far.size ())
249 return solve (start, end, max_systems);
252 std::vector<Line_details>
253 Constrained_breaking::line_details (vsize start, vsize end, vsize sys_count)
255 vsize end_brk = prepare_solution (start, end, sys_count);
256 Matrix<Constrained_break_node> const &st = state_[start];
257 vector<Line_details> ret;
259 /* This loop structure is C&Ped from solve(). */
260 /* find the first solution that satisfies constraints */
261 for (vsize sys = sys_count - 1; sys != VPOS; sys--)
263 for (vsize brk = end_brk; brk != VPOS; brk--)
265 if (!isinf (st.at (brk, sys).details_.force_))
270 During initialize(), we only fill out a
271 Line_details for lines that are valid (ie. not too
272 long), otherwise line breaking becomes O(n^3).
273 In case sys_count is such that no valid solution
274 is found, we need to fill in the Line_details.
276 Line_details details;
277 brk = st.at (brk, sys).prev_;
279 fill_line_details (&details, brk, end_brk);
280 ret.push_back (details);
283 /* build up the good part of the solution */
284 for (vsize cur_sys = sys; cur_sys != VPOS; cur_sys--)
286 vsize prev_brk = st.at (brk, cur_sys).prev_;
287 assert (brk != VPOS);
288 ret.push_back (st.at (brk, cur_sys).details_);
297 /* if we get to here, just put everything on one line */
299 Line_details details;
300 fill_line_details (&details, 0, end_brk);
301 ret.push_back (details);
307 Constrained_breaking::min_system_count (vsize start, vsize end)
310 vsize brk = prepare_solution (start, end, 1);
311 vsize rank = breaks_.size () - starting_breakpoints_[start];
312 Matrix<Constrained_break_node> const &st = state_[start];
314 /* sys_count < rank : rank is the # of breakpoints, we can't have more systems */
315 for (sys_count = 0; sys_count < rank; sys_count++)
317 if (sys_count >= valid_systems_)
319 resize (sys_count + 3);
321 if (!isinf (st.at (brk, sys_count).details_.force_))
322 return sys_count + 1;
324 /* no possible breaks satisfy constraints */
329 Constrained_breaking::max_system_count (vsize start, vsize end)
331 vsize brk = (end >= start_.size ()) ? breaks_.size () - 1 : starting_breakpoints_[end];
332 return brk - starting_breakpoints_[start];
336 Constrained_breaking::prepare_solution (vsize start, vsize end, vsize sys_count)
338 assert (start < start_.size () && (end == VPOS || end <= start_.size ()));
339 assert (start < end);
342 if (end == start_.size ())
346 brk = end == VPOS ? breaks_.size () - 1 : starting_breakpoints_[end];
347 brk -= starting_breakpoints_[start];
351 Constrained_breaking::Constrained_breaking (Paper_score *ps)
353 valid_systems_ = systems_ = 0;
354 start_.push_back (0);
359 Constrained_breaking::Constrained_breaking (Paper_score *ps, vector<vsize> const &start)
362 valid_systems_ = systems_ = 0;
368 min_permission (SCM perm1, SCM perm2)
370 if (scm_is_eq (perm1, ly_symbol2scm ("force")))
372 if (scm_is_eq (perm1, ly_symbol2scm ("allow"))
373 && !scm_is_eq (perm2, ly_symbol2scm ("force")))
378 /* find the forces for all possible lines and cache ragged_ and ragged_right_ */
380 Constrained_breaking::initialize ()
385 ragged_right_ = to_boolean (pscore_->layout ()->c_variable ("ragged-right"));
386 ragged_last_ = to_boolean (pscore_->layout ()->c_variable ("ragged-last"));
387 system_system_space_ = 0;
388 system_markup_space_ = 0;
389 system_system_padding_ = 0;
390 system_system_min_distance_ = 0;
391 score_system_padding_ = 0;
392 score_system_min_distance_ = 0;
393 score_markup_padding_ = 0;
394 score_markup_min_distance_ = 0;
396 Output_def *l = pscore_->layout ();
398 SCM spacing_spec = l->c_variable ("system-system-spacing");
399 SCM between_scores_spec = l->c_variable ("score-system-spacing");
400 SCM title_spec = l->c_variable ("score-markup-spacing");
401 SCM page_breaking_spacing_spec = l->c_variable ("page-breaking-system-system-spacing");
403 Page_layout_problem::read_spacing_spec (spacing_spec,
404 &system_system_space_,
405 ly_symbol2scm ("basic-distance"));
406 Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec,
407 &system_system_space_,
408 ly_symbol2scm ("basic-distance"));
409 Page_layout_problem::read_spacing_spec (title_spec,
410 &system_markup_space_,
411 ly_symbol2scm ("basic-distance"));
413 Page_layout_problem::read_spacing_spec (spacing_spec,
414 &system_system_padding_,
415 ly_symbol2scm ("padding"));
416 Page_layout_problem::read_spacing_spec (between_scores_spec,
417 &score_system_padding_,
418 ly_symbol2scm ("padding"));
419 Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec,
420 &system_system_padding_,
421 ly_symbol2scm ("padding"));
422 Page_layout_problem::read_spacing_spec (title_spec,
423 &score_markup_padding_,
424 ly_symbol2scm ("padding"));
426 Page_layout_problem::read_spacing_spec (between_scores_spec,
427 &score_system_min_distance_,
428 ly_symbol2scm ("minimum-distance"));
429 Page_layout_problem::read_spacing_spec (spacing_spec,
430 &system_system_min_distance_,
431 ly_symbol2scm ("minimum-distance"));
432 Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec,
433 &system_system_min_distance_,
434 ly_symbol2scm ("minimum-distance"));
435 Page_layout_problem::read_spacing_spec (title_spec,
436 &score_markup_min_distance_,
437 ly_symbol2scm ("minimum-distance"));
439 Interval first_line = line_dimensions_int (pscore_->layout (), 0);
440 Interval other_lines = line_dimensions_int (pscore_->layout (), 1);
441 /* do all the rod/spring problems */
442 breaks_ = pscore_->get_break_indices ();
443 all_ = pscore_->root_system ()->used_columns ();
444 lines_.resize (breaks_.size (), breaks_.size (), Line_details ());
445 vector<Real> forces = get_line_forces (all_,
446 other_lines.length (),
447 other_lines.length () - first_line.length (),
449 for (vsize i = 0; i + 1 < breaks_.size (); i++)
451 for (vsize j = i + 1; j < breaks_.size (); j++)
453 bool last = j == breaks_.size () - 1;
454 bool ragged = ragged_right_ || (last && ragged_last_);
455 Line_details &line = lines_.at (j, i);
457 line.force_ = forces[i * breaks_.size () + j];
458 if (ragged && last && !isinf (line.force_))
459 line.force_ = (line.force_ < 0 && j > i + 1) ? infinity_f : 0;
460 if (isinf (line.force_))
463 fill_line_details (&line, i, j);
467 /* work out all the starting indices */
468 for (vsize i = 0; i < start_.size (); i++)
471 for (j = 0; j + 1 < breaks_.size () && breaks_[j] < start_[i]; j++)
473 starting_breakpoints_.push_back (j);
474 start_[i] = breaks_[j];
476 state_.resize (start_.size ());
480 Fills out all of the information contained in a Line_details,
481 except for information about horizontal spacing.
484 Constrained_breaking::fill_line_details (Line_details *const out, vsize start, vsize end)
486 int start_rank = Paper_column::get_rank (all_[breaks_[start]]);
487 int end_rank = Paper_column::get_rank (all_[breaks_[end]]);
488 System *sys = pscore_->root_system ();
489 Interval begin_of_line_extent = sys->begin_of_line_pure_height (start_rank, end_rank);
490 Interval rest_of_line_extent = sys->rest_of_line_pure_height (start_rank, end_rank);
491 bool last = (end == breaks_.size () - 1);
493 Grob *c = all_[breaks_[end]];
494 out->last_column_ = c;
495 out->break_penalty_ = robust_scm2double (c->get_property ("line-break-penalty"), 0);
496 out->page_penalty_ = robust_scm2double (c->get_property ("page-break-penalty"), 0);
497 out->turn_penalty_ = robust_scm2double (c->get_property ("page-turn-penalty"), 0);
498 out->break_permission_ = c->get_property ("line-break-permission");
499 out->page_permission_ = c->get_property ("page-break-permission");
500 out->turn_permission_ = c->get_property ("page-turn-permission");
502 /* turn permission should always be stricter than page permission
503 and page permission should always be stricter than line permission */
504 out->page_permission_ = min_permission (out->break_permission_,
505 out->page_permission_);
506 out->turn_permission_ = min_permission (out->page_permission_,
507 out->turn_permission_);
509 begin_of_line_extent = (begin_of_line_extent.is_empty ()
510 || isnan (begin_of_line_extent[LEFT])
511 || isnan (begin_of_line_extent[RIGHT]))
512 ? Interval (0, 0) : begin_of_line_extent;
513 rest_of_line_extent = (rest_of_line_extent.is_empty ()
514 || isnan (rest_of_line_extent[LEFT])
515 || isnan (rest_of_line_extent[RIGHT]))
516 ? Interval (0, 0) : rest_of_line_extent;
517 out->shape_ = Line_shape (begin_of_line_extent, rest_of_line_extent);
518 out->padding_ = last ? score_system_padding_ : system_system_padding_;
519 out->title_padding_ = score_markup_padding_;
520 out->min_distance_ = last ? score_system_min_distance_ : system_system_min_distance_;
521 out->title_min_distance_ = score_markup_min_distance_;
522 out->space_ = system_system_space_;
523 out->title_space_ = system_markup_space_;
524 out->inverse_hooke_ = out->full_height () + system_system_space_;
526 out->footnote_heights_ = sys->get_footnote_heights_in_range (start_rank, end_rank);
527 out->in_note_heights_ = sys->get_in_note_heights_in_range (start_rank, end_rank);
529 out->refpoint_extent_ = sys->pure_refpoint_extent (start_rank, end_rank);
530 if (out->refpoint_extent_.is_empty ())
531 out->refpoint_extent_ = Interval (0, 0);
535 Constrained_breaking::combine_demerits (Real force, Real prev_force)
538 return force * force;
540 return force * force + (prev_force - force) * (prev_force - force);
543 Line_details::Line_details (Prob *pb, Output_def *paper)
545 SCM spec = paper->c_variable ("markup-system-spacing");
546 SCM title_spec = paper->c_variable ("markup-markup-spacing");
550 title_min_distance_ = 0;
553 Page_layout_problem::read_spacing_spec (spec, &space_, ly_symbol2scm ("basic-distance"));
554 Page_layout_problem::read_spacing_spec (title_spec, &title_space_, ly_symbol2scm ("basic-distance"));
555 Page_layout_problem::read_spacing_spec (spec, &padding_, ly_symbol2scm ("padding"));
556 Page_layout_problem::read_spacing_spec (title_spec, &title_padding_, ly_symbol2scm ("padding"));
557 Page_layout_problem::read_spacing_spec (spec, &min_distance_, ly_symbol2scm ("minimum-distance"));
558 Page_layout_problem::read_spacing_spec (title_spec, &title_min_distance_, ly_symbol2scm ("minimum-distance"));
560 SCM footnotes = pb->get_property ("footnotes");
562 if (scm_is_pair (footnotes))
563 for (SCM s = footnotes; scm_is_pair (s); s = scm_cdr (s))
565 Stencil *sten = unsmob<Stencil> (scm_caddar (s));
568 programming_error ("expecting stencil, got empty pointer");
571 footnote_heights_.push_back (sten->extent (Y_AXIS).length ());
576 Stencil *st = unsmob<Stencil> (pb->get_property ("stencil"));
577 Interval stencil_extent = st->is_empty (Y_AXIS) ? Interval (0, 0)
578 : st->extent (Y_AXIS);
579 shape_ = Line_shape (stencil_extent, stencil_extent); // pretend it goes all the way across
582 inverse_hooke_ = 1.0;
583 break_permission_ = ly_symbol2scm ("allow");
584 page_permission_ = pb->get_property ("page-break-permission");
585 turn_permission_ = pb->get_property ("page-turn-permission");
587 page_penalty_ = robust_scm2double (pb->get_property ("page-break-penalty"), 0);
588 turn_penalty_ = robust_scm2double (pb->get_property ("page-turn-penalty"), 0);
589 title_ = to_boolean (pb->get_property ("is-title"));
590 compressed_lines_count_ = 1;
591 compressed_nontitle_lines_count_ = title_ ? 0 : 1;
592 SCM last_scm = pb->get_property ("last-markup-line");
593 last_markup_line_ = to_boolean (last_scm);
594 SCM first_scm = pb->get_property ("first-markup-line");
595 first_markup_line_ = to_boolean (first_scm);
596 tight_spacing_ = to_boolean (pb->get_property ("tight-spacing"));
597 refpoint_extent_ = Interval (0, 0);
601 Line_details::full_height () const
604 ret.unite (shape_.begin_);
605 ret.unite (shape_.rest_);
606 return ret.length ();
610 Line_details::tallness () const
616 Line_details::spring_length (Line_details const &next_line) const
618 // space_ measures the spring which goes from the bottom refpoint
619 // of this to the top refpoint of next_line. We want to return
620 // the stretchable space between the bottom of this's extent to
621 // the top of next_line's extent.
622 Real refpoint_dist = tallness_ + refpoint_extent_[DOWN] - next_line.refpoint_extent_[UP];
623 Real space = next_line.title_ ? title_space_ : space_;
624 return std::max (0.0, space - refpoint_dist);
627 Line_shape::Line_shape (Interval begin, Interval rest)
634 Line_shape::piggyback (Line_shape mount, Real padding) const
636 Real elevation = std::max (begin_[UP] - mount.begin_[DOWN], rest_[UP] - mount.rest_[DOWN]);
637 Interval begin = Interval (begin_[DOWN], elevation + mount.begin_[UP] + padding);
638 Interval rest = Interval (rest_[DOWN], elevation + mount.rest_[UP] + padding);
639 return Line_shape (begin, rest);