2 This file is part of LilyPond, the GNU music typesetter.
4 Copyright (C) 2006--2012 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"
33 We use the following optimal substructure. Let W (A) be our weight function.
35 Let A_{k, n} = (a_{k, n, 1}, ... a_{k, n, k}) be the optimal set of line breaks
36 for k systems and n potential breakpoints. a_{k, n, k} = n (it is the end of
39 Then A_{k+1, m} is contructed from
40 min_ {k < j < m} ( W (A_{k, j} :: m) )
41 where by A::m we denote appending m to the list A
45 The above algorithm makes it easy to end at a point before the end of the
46 score (just find A_{k, m} for some m < breaks_.size () - 1). However, we must
47 add information for starting at a point after the beginning. One constructor
48 allows the specification of a list of starting columns, start_. We then have
49 start_.size () different solution arrays. state_[i] is the array for the
50 solution starting at column number start_[i].
52 The indices "start" and "end" refer to the index in the start_ array of the
53 desired starting and ending columns.
55 each solution array looks like
56 a_{1,1,1} a_{2,1,2} a_{3,1,3} . . .
57 X a_{2,2,2} a_{3,2,3} . . .
61 where the X's mark invalid solutions (can't have more systems than
62 breakpoints). Note that each value is of the form a_{x, n, x}. This is because
63 a breakpoint of the form a_{x, n, x-1} will also be called a_{x-1, m, x-1} for
64 some m < n. Each cell in the array stores the value of its m (ie. the
65 ending breakpoint of the previous line) as "prev_".
67 For finding A_{sys, brk}, let "me" be the (sys_count, brk) cell in our
68 solution array (state_[start][sys * rank + brk]).
70 Then A_{sys, brk} = A_{sys - 1, me.prev_} :: me
74 start and sys here are indexed from 0.
75 brk is indexed from starting_breakpoints_[start]
76 (for brk, starting_breakpoints_[start] is the beginning
77 of the piece; the smallest value we should ever see here is
78 starting_breakpoints_[start] + 1) */
80 Constrained_breaking::calc_subproblem (vsize start, vsize sys, vsize brk)
82 assert (sys < systems_);
83 assert (start < start_.size ());
84 assert (brk < breaks_.size ());
86 bool found_something = false;
87 vsize start_col = starting_breakpoints_[start];
88 Matrix<Constrained_break_node> &st = state_[start];
89 vsize max_index = brk - start_col;
90 for (vsize j = max_index; j-- > sys;)
92 if (0 == sys && j > 0)
93 continue; /* the first line cannot have its first break after the beginning */
95 Line_details const &cur = lines_.at (brk, j + start_col);
96 if (isinf (cur.force_))
104 prev_f = st.at (j, sys - 1).details_.force_;
105 prev_dem = st.at (j, sys - 1).demerits_;
107 if (isinf (prev_dem))
110 Real dem = combine_demerits (cur.force_, prev_f) + prev_dem + cur.break_penalty_;
111 Constrained_break_node &n = st.at (max_index, sys);
112 if (dem < n.demerits_)
114 found_something = true;
120 return found_something;
124 Constrained_breaking::space_line (vsize i, vsize j)
126 bool ragged_right = to_boolean (pscore_->layout ()->c_variable ("ragged-right"));
127 bool ragged_last = to_boolean (pscore_->layout ()->c_variable ("ragged-last"));
129 vector<Grob *> line (all_.begin () + breaks_[i],
130 all_.begin () + breaks_[j] + 1);
131 Interval line_dims = line_dimensions_int (pscore_->layout (), i);
132 bool last = j == breaks_.size () - 1;
133 bool ragged = ragged_right || (last && ragged_last);
135 /* As a special case, if there is only one line in the score and ragged-right
136 hasn't been specifically forbidden and the line is stretched, use
139 && lines_.at (i, j).force_ >= 0
140 && !scm_is_bool (pscore_->layout ()->c_variable ("ragged-right"))
141 && !scm_is_bool (pscore_->layout ()->c_variable ("ragged-last")))
144 return get_line_configuration (line, line_dims[RIGHT] - line_dims[LEFT], line_dims[LEFT], ragged);
148 Constrained_breaking::resize (vsize systems)
152 if (pscore_ && systems_ > valid_systems_)
154 for (vsize i = 0; i < state_.size (); i++)
155 state_[i].resize (breaks_.size () - starting_breakpoints_[i], systems_, Constrained_break_node ());
157 /* fill out the matrices */
158 for (vsize i = 0; i < state_.size (); i++)
159 for (vsize j = valid_systems_; j < systems_; j++)
160 for (vsize k = starting_breakpoints_[i] + j + 1; k < breaks_.size (); k++)
161 if (!calc_subproblem (i, j, k))
162 break; /* if we couldn't break this, it is too cramped already */
163 valid_systems_ = systems_;
167 vector<Column_x_positions>
168 Constrained_breaking::solve (vsize start, vsize end, vsize sys_count)
170 vsize start_brk = starting_breakpoints_[start];
171 vsize end_brk = prepare_solution (start, end, sys_count);
173 Matrix<Constrained_break_node> const &st = state_[start];
174 vector<Column_x_positions> ret;
176 /* find the first solution that satisfies constraints */
177 for (vsize sys = sys_count - 1; sys != VPOS; sys--)
179 for (vsize brk = end_brk; brk != VPOS; brk--)
181 if (!isinf (st.at (brk, sys).details_.force_))
185 brk = st.at (brk, sys).prev_;
187 warning (_ ("cannot find line breaking that satisfies constraints"));
188 ret.push_back (space_line (brk, end_brk));
191 /* build up the good part of the solution */
192 for (vsize cur_sys = sys; cur_sys != VPOS; cur_sys--)
194 vsize prev_brk = st.at (brk, cur_sys).prev_;
195 assert (brk != VPOS);
196 ret.push_back (space_line (prev_brk + start_brk, brk + start_brk));
204 /* if we get to here, just put everything on one line */
206 warning (_ ("cannot find line breaking that satisfies constraints"));
207 ret.push_back (space_line (0, end_brk));
212 vector<Column_x_positions>
213 Constrained_breaking::best_solution (vsize start, vsize end)
215 vsize min_systems = min_system_count (start, end);
216 vsize max_systems = max_system_count (start, end);
217 Real best_demerits = infinity_f;
218 vector<Column_x_positions> best_so_far;
220 for (vsize i = min_systems; i <= max_systems; i++)
222 vsize brk = prepare_solution (start, end, i);
223 Real dem = state_[start].at (brk, i - 1).demerits_;
225 if (dem < best_demerits)
228 best_so_far = solve (start, end, i);
232 vector<Column_x_positions> cur = solve (start, end, i);
233 bool too_many_lines = true;
235 for (vsize j = 0; j < cur.size (); j++)
236 if (cur[j].force_ < 0)
238 too_many_lines = false;
245 if (best_so_far.size ())
247 return solve (start, end, max_systems);
250 std::vector<Line_details>
251 Constrained_breaking::line_details (vsize start, vsize end, vsize sys_count)
253 vsize end_brk = prepare_solution (start, end, sys_count);
254 Matrix<Constrained_break_node> const &st = state_[start];
255 vector<Line_details> ret;
257 /* This loop structure is C&Ped from solve(). */
258 /* find the first solution that satisfies constraints */
259 for (vsize sys = sys_count - 1; sys != VPOS; sys--)
261 for (vsize brk = end_brk; brk != VPOS; brk--)
263 if (!isinf (st.at (brk, sys).details_.force_))
268 During initialize(), we only fill out a
269 Line_details for lines that are valid (ie. not too
270 long), otherwise line breaking becomes O(n^3).
271 In case sys_count is such that no valid solution
272 is found, we need to fill in the Line_details.
274 Line_details details;
275 brk = st.at (brk, sys).prev_;
277 fill_line_details (&details, brk, end_brk);
278 ret.push_back (details);
281 /* build up the good part of the solution */
282 for (vsize cur_sys = sys; cur_sys != VPOS; cur_sys--)
284 vsize prev_brk = st.at (brk, cur_sys).prev_;
285 assert (brk != VPOS);
286 ret.push_back (st.at (brk, cur_sys).details_);
295 /* if we get to here, just put everything on one line */
297 Line_details details;
298 fill_line_details (&details, 0, end_brk);
299 ret.push_back (details);
305 Constrained_breaking::min_system_count (vsize start, vsize end)
308 vsize brk = prepare_solution (start, end, 1);
309 vsize rank = breaks_.size () - starting_breakpoints_[start];
310 Matrix<Constrained_break_node> const &st = state_[start];
312 /* sys_count < rank : rank is the # of breakpoints, we can't have more systems */
313 for (sys_count = 0; sys_count < rank; sys_count++)
315 if (sys_count >= valid_systems_)
317 resize (sys_count + 3);
319 if (!isinf (st.at (brk, sys_count).details_.force_))
320 return sys_count + 1;
322 /* no possible breaks satisfy constraints */
327 Constrained_breaking::max_system_count (vsize start, vsize end)
329 vsize brk = (end >= start_.size ()) ? breaks_.size () - 1 : starting_breakpoints_[end];
330 return brk - starting_breakpoints_[start];
334 Constrained_breaking::prepare_solution (vsize start, vsize end, vsize sys_count)
336 assert (start < start_.size () && (end == VPOS || end <= start_.size ()));
337 assert (start < end);
340 if (end == start_.size ())
344 brk = end == VPOS ? breaks_.size () - 1 : starting_breakpoints_[end];
345 brk -= starting_breakpoints_[start];
349 Constrained_breaking::Constrained_breaking (Paper_score *ps)
351 valid_systems_ = systems_ = 0;
352 start_.push_back (0);
357 Constrained_breaking::Constrained_breaking (Paper_score *ps, vector<vsize> const &start)
360 valid_systems_ = systems_ = 0;
366 min_permission (SCM perm1, SCM perm2)
368 if (perm1 == ly_symbol2scm ("force"))
370 if (perm1 == ly_symbol2scm ("allow")
371 && perm2 != ly_symbol2scm ("force"))
376 /* find the forces for all possible lines and cache ragged_ and ragged_right_ */
378 Constrained_breaking::initialize ()
383 ragged_right_ = to_boolean (pscore_->layout ()->c_variable ("ragged-right"));
384 ragged_last_ = to_boolean (pscore_->layout ()->c_variable ("ragged-last"));
385 system_system_space_ = 0;
386 system_markup_space_ = 0;
387 system_system_padding_ = 0;
388 system_system_min_distance_ = 0;
389 score_system_padding_ = 0;
390 score_system_min_distance_ = 0;
391 score_markup_padding_ = 0;
392 score_markup_min_distance_ = 0;
394 Output_def *l = pscore_->layout ();
396 SCM spacing_spec = l->c_variable ("system-system-spacing");
397 SCM between_scores_spec = l->c_variable ("score-system-spacing");
398 SCM title_spec = l->c_variable ("score-markup-spacing");
399 SCM page_breaking_spacing_spec = l->c_variable ("page-breaking-system-system-spacing");
401 Page_layout_problem::read_spacing_spec (spacing_spec,
402 &system_system_space_,
403 ly_symbol2scm ("basic-distance"));
404 Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec,
405 &system_system_space_,
406 ly_symbol2scm ("basic-distance"));
407 Page_layout_problem::read_spacing_spec (title_spec,
408 &system_markup_space_,
409 ly_symbol2scm ("basic-distance"));
411 Page_layout_problem::read_spacing_spec (spacing_spec,
412 &system_system_padding_,
413 ly_symbol2scm ("padding"));
414 Page_layout_problem::read_spacing_spec (between_scores_spec,
415 &score_system_padding_,
416 ly_symbol2scm ("padding"));
417 Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec,
418 &system_system_padding_,
419 ly_symbol2scm ("padding"));
420 Page_layout_problem::read_spacing_spec (title_spec,
421 &score_markup_padding_,
422 ly_symbol2scm ("padding"));
424 Page_layout_problem::read_spacing_spec (between_scores_spec,
425 &score_system_min_distance_,
426 ly_symbol2scm ("minimum-distance"));
427 Page_layout_problem::read_spacing_spec (spacing_spec,
428 &system_system_min_distance_,
429 ly_symbol2scm ("minimum-distance"));
430 Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec,
431 &system_system_min_distance_,
432 ly_symbol2scm ("minimum-distance"));
433 Page_layout_problem::read_spacing_spec (title_spec,
434 &score_markup_min_distance_,
435 ly_symbol2scm ("minimum-distance"));
437 Interval first_line = line_dimensions_int (pscore_->layout (), 0);
438 Interval other_lines = line_dimensions_int (pscore_->layout (), 1);
439 /* do all the rod/spring problems */
440 breaks_ = pscore_->get_break_indices ();
441 all_ = pscore_->root_system ()->used_columns ();
442 lines_.resize (breaks_.size (), breaks_.size (), Line_details ());
443 vector<Real> forces = get_line_forces (all_,
444 other_lines.length (),
445 other_lines.length () - first_line.length (),
447 for (vsize i = 0; i + 1 < breaks_.size (); i++)
449 for (vsize j = i + 1; j < breaks_.size (); j++)
451 bool last = j == breaks_.size () - 1;
452 bool ragged = ragged_right_ || (last && ragged_last_);
453 Line_details &line = lines_.at (j, i);
455 line.force_ = forces[i * breaks_.size () + j];
456 if (ragged && last && !isinf (line.force_))
457 line.force_ = (line.force_ < 0 && j > i + 1) ? infinity_f : 0;
458 if (isinf (line.force_))
461 fill_line_details (&line, i, j);
465 /* work out all the starting indices */
466 for (vsize i = 0; i < start_.size (); i++)
469 for (j = 0; j + 1 < breaks_.size () && breaks_[j] < start_[i]; j++)
471 starting_breakpoints_.push_back (j);
472 start_[i] = breaks_[j];
474 state_.resize (start_.size ());
478 Fills out all of the information contained in a Line_details,
479 except for information about horizontal spacing.
482 Constrained_breaking::fill_line_details (Line_details *const out, vsize start, vsize end)
484 int start_rank = Paper_column::get_rank (all_[breaks_[start]]);
485 int end_rank = Paper_column::get_rank (all_[breaks_[end]]);
486 System *sys = pscore_->root_system ();
487 Interval begin_of_line_extent = sys->begin_of_line_pure_height (start_rank, end_rank);
488 Interval rest_of_line_extent = sys->rest_of_line_pure_height (start_rank, end_rank);
489 bool last = (end == breaks_.size () - 1);
491 Grob *c = all_[breaks_[end]];
492 out->last_column_ = c;
493 out->break_penalty_ = robust_scm2double (c->get_property ("line-break-penalty"), 0);
494 out->page_penalty_ = robust_scm2double (c->get_property ("page-break-penalty"), 0);
495 out->turn_penalty_ = robust_scm2double (c->get_property ("page-turn-penalty"), 0);
496 out->break_permission_ = c->get_property ("line-break-permission");
497 out->page_permission_ = c->get_property ("page-break-permission");
498 out->turn_permission_ = c->get_property ("page-turn-permission");
500 /* turn permission should always be stricter than page permission
501 and page permission should always be stricter than line permission */
502 out->page_permission_ = min_permission (out->break_permission_,
503 out->page_permission_);
504 out->turn_permission_ = min_permission (out->page_permission_,
505 out->turn_permission_);
507 begin_of_line_extent = (begin_of_line_extent.is_empty ()
508 || isnan (begin_of_line_extent[LEFT])
509 || isnan (begin_of_line_extent[RIGHT]))
510 ? Interval (0, 0) : begin_of_line_extent;
511 rest_of_line_extent = (rest_of_line_extent.is_empty ()
512 || isnan (rest_of_line_extent[LEFT])
513 || isnan (rest_of_line_extent[RIGHT]))
514 ? Interval (0, 0) : rest_of_line_extent;
515 out->shape_ = Line_shape (begin_of_line_extent, rest_of_line_extent);
516 out->padding_ = last ? score_system_padding_ : system_system_padding_;
517 out->title_padding_ = score_markup_padding_;
518 out->min_distance_ = last ? score_system_min_distance_ : system_system_min_distance_;
519 out->title_min_distance_ = score_markup_min_distance_;
520 out->space_ = system_system_space_;
521 out->title_space_ = system_markup_space_;
522 out->inverse_hooke_ = out->full_height () + system_system_space_;
524 out->footnote_heights_ = sys->get_footnote_heights_in_range (start_rank, end_rank);
525 out->in_note_heights_ = sys->get_in_note_heights_in_range (start_rank, end_rank);
527 out->refpoint_extent_ = sys->pure_refpoint_extent (start_rank, end_rank);
528 if (out->refpoint_extent_.is_empty ())
529 out->refpoint_extent_ = Interval (0, 0);
533 Constrained_breaking::combine_demerits (Real force, Real prev_force)
536 return force * force;
538 return force * force + (prev_force - force) * (prev_force - force);
541 Line_details::Line_details (Prob *pb, Output_def *paper)
543 SCM spec = paper->c_variable ("markup-system-spacing");
544 SCM title_spec = paper->c_variable ("markup-markup-spacing");
548 title_min_distance_ = 0;
551 Page_layout_problem::read_spacing_spec (spec, &space_, ly_symbol2scm ("basic-distance"));
552 Page_layout_problem::read_spacing_spec (title_spec, &title_space_, ly_symbol2scm ("basic-distance"));
553 Page_layout_problem::read_spacing_spec (spec, &padding_, ly_symbol2scm ("padding"));
554 Page_layout_problem::read_spacing_spec (title_spec, &title_padding_, ly_symbol2scm ("padding"));
555 Page_layout_problem::read_spacing_spec (spec, &min_distance_, ly_symbol2scm ("minimum-distance"));
556 Page_layout_problem::read_spacing_spec (title_spec, &title_min_distance_, ly_symbol2scm ("minimum-distance"));
558 SCM footnotes = pb->get_property ("footnotes");
560 if (scm_is_pair (footnotes))
561 for (SCM s = footnotes; scm_is_pair (s); s = scm_cdr (s))
563 Stencil *sten = unsmob_stencil (scm_caddar (s));
566 programming_error ("expecting stencil, got empty pointer");
569 footnote_heights_.push_back (sten->extent (Y_AXIS).length ());
574 Interval stencil_extent = unsmob_stencil (pb->get_property ("stencil"))->extent (Y_AXIS);
575 shape_ = Line_shape (stencil_extent, stencil_extent); // pretend it goes all the way across
578 inverse_hooke_ = 1.0;
579 break_permission_ = ly_symbol2scm ("allow");
580 page_permission_ = pb->get_property ("page-break-permission");
581 turn_permission_ = pb->get_property ("page-turn-permission");
583 page_penalty_ = robust_scm2double (pb->get_property ("page-break-penalty"), 0);
584 turn_penalty_ = robust_scm2double (pb->get_property ("page-turn-penalty"), 0);
585 title_ = to_boolean (pb->get_property ("is-title"));
586 compressed_lines_count_ = 1;
587 compressed_nontitle_lines_count_ = title_ ? 0 : 1;
588 SCM last_scm = pb->get_property ("last-markup-line");
589 last_markup_line_ = to_boolean (last_scm);
590 SCM first_scm = pb->get_property ("first-markup-line");
591 first_markup_line_ = to_boolean (first_scm);
592 tight_spacing_ = to_boolean (pb->get_property ("tight-spacing"));
593 refpoint_extent_ = Interval (0, 0);
597 Line_details::full_height () const
600 ret.unite (shape_.begin_);
601 ret.unite (shape_.rest_);
602 return ret.length ();
606 Line_details::tallness () const
612 Line_details::spring_length (Line_details const &next_line) const
614 // space_ measures the spring which goes from the bottom refpoint
615 // of this to the top refpoint of next_line. We want to return
616 // the stretchable space between the bottom of this's extent to
617 // the top of next_line's extent.
618 Real refpoint_dist = tallness_ + refpoint_extent_[DOWN] - next_line.refpoint_extent_[UP];
619 Real space = next_line.title_ ? title_space_ : space_;
620 return max (0.0, space - refpoint_dist);
623 Line_shape::Line_shape (Interval begin, Interval rest)
630 Line_shape::piggyback (Line_shape mount, Real padding) const
632 Real elevation = max (begin_[UP] - mount.begin_[DOWN], rest_[UP] - mount.rest_[DOWN]);
633 Interval begin = Interval (begin_[DOWN], elevation + mount.begin_[UP] + padding);
634 Interval rest = Interval (rest_[DOWN], elevation + mount.rest_[UP] + padding);
635 return Line_shape (begin, rest);