2 This file is part of LilyPond, the GNU music typesetter.
4 Copyright (C) 2006--2011 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;
125 Constrained_breaking::space_line (vsize i, vsize j)
127 bool ragged_right = to_boolean (pscore_->layout ()->c_variable ("ragged-right"));
128 bool ragged_last = to_boolean (pscore_->layout ()->c_variable ("ragged-last"));
130 vector<Grob*> line (all_.begin () + breaks_[i],
131 all_.begin () + breaks_[j] + 1);
132 Interval line_dims = line_dimensions_int (pscore_->layout (), i);
133 bool last = j == breaks_.size () - 1;
134 bool ragged = ragged_right || (last && ragged_last);
136 /* As a special case, if there is only one line in the score and ragged-right
137 hasn't been specifically forbidden and the line is stretched, use
140 && lines_.at (i, j).force_ >= 0
141 && !scm_is_bool (pscore_->layout ()->c_variable ("ragged-right"))
142 && !scm_is_bool (pscore_->layout ()->c_variable ("ragged-last")))
145 return get_line_configuration (line, line_dims[RIGHT] - line_dims[LEFT], line_dims[LEFT], ragged);
149 Constrained_breaking::resize (vsize systems)
153 if (pscore_ && systems_ > valid_systems_)
155 for (vsize i = 0; i < state_.size (); i++)
156 state_[i].resize (breaks_.size () - starting_breakpoints_[i], systems_, Constrained_break_node ());
158 /* fill out the matrices */
159 for (vsize i = 0; i < state_.size (); i++)
160 for (vsize j = valid_systems_; j < systems_; j++)
161 for (vsize k = starting_breakpoints_[i] + j + 1; k < breaks_.size (); k++)
162 if (!calc_subproblem (i, j, k))
163 break; /* if we couldn't break this, it is too cramped already */
164 valid_systems_ = systems_;
168 vector<Column_x_positions>
169 Constrained_breaking::solve (vsize start, vsize end, vsize sys_count)
171 vsize start_brk = starting_breakpoints_[start];
172 vsize end_brk = prepare_solution (start, end, sys_count);
174 Matrix<Constrained_break_node> const &st = state_[start];
175 vector<Column_x_positions> ret;
177 /* find the first solution that satisfies constraints */
178 for (vsize sys = sys_count-1; sys != VPOS; sys--)
180 for (vsize brk = end_brk; brk != VPOS; brk--)
182 if (!isinf (st.at (brk, sys).details_.force_))
186 brk = st.at (brk, sys).prev_;
188 warning (_ ("cannot find line breaking that satisfies constraints"));
189 ret.push_back (space_line (brk, end_brk));
192 /* build up the good part of the solution */
193 for (vsize cur_sys = sys; cur_sys != VPOS; cur_sys--)
195 vsize prev_brk = st.at (brk, cur_sys).prev_;
196 assert (brk != VPOS);
197 ret.push_back (space_line (prev_brk + start_brk, brk + start_brk));
205 /* 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));
211 vector<Column_x_positions>
212 Constrained_breaking::best_solution (vsize start, vsize end)
214 vsize min_systems = min_system_count (start, end);
215 vsize max_systems = max_system_count (start, end);
216 Real best_demerits = infinity_f;
217 vector<Column_x_positions> best_so_far;
219 for (vsize i = min_systems; i <= max_systems; i++)
221 vsize brk = prepare_solution (start, end, i);
222 Real dem = state_[start].at (brk, i-1).demerits_;
224 if (dem < best_demerits)
227 best_so_far = solve (start, end, i);
231 vector<Column_x_positions> cur = solve (start, end, i);
232 bool too_many_lines = true;
234 for (vsize j = 0; j < cur.size (); j++)
235 if (cur[j].force_ < 0)
237 too_many_lines = false;
244 if (best_so_far.size ())
246 return solve (start, end, max_systems);
249 std::vector<Line_details>
250 Constrained_breaking::line_details (vsize start, vsize end, vsize sys_count)
252 vsize end_brk = prepare_solution (start, end, sys_count);
253 Matrix<Constrained_break_node> const &st = state_[start];
254 vector<Line_details> ret;
256 /* This loop structure is C&Ped from solve(). */
257 /* find the first solution that satisfies constraints */
258 for (vsize sys = sys_count-1; sys != VPOS; sys--)
260 for (vsize brk = end_brk; brk != VPOS; brk--)
262 if (!isinf (st.at (brk, sys).details_.force_))
267 During initialize(), we only fill out a
268 Line_details for lines that are valid (ie. not too
269 long), otherwise line breaking becomes O(n^3).
270 In case sys_count is such that no valid solution
271 is found, we need to fill in the Line_details.
273 Line_details details;
274 brk = st.at (brk, sys).prev_;
276 fill_line_details (&details, brk, end_brk);
277 ret.push_back (details);
280 /* build up the good part of the solution */
281 for (vsize cur_sys = sys; cur_sys != VPOS; cur_sys--)
283 vsize prev_brk = st.at (brk, cur_sys).prev_;
284 assert (brk != VPOS);
285 ret.push_back (st.at (brk, cur_sys).details_);
294 /* if we get to here, just put everything on one line */
295 Line_details details;
296 fill_line_details (&details, 0, end_brk);
297 ret.push_back (details);
302 Constrained_breaking::min_system_count (vsize start, vsize end)
305 vsize brk = prepare_solution (start, end, 1);
306 vsize rank = breaks_.size () - starting_breakpoints_[start];
307 Matrix<Constrained_break_node> const &st = state_[start];
309 /* sys_count < rank : rank is the # of breakpoints, we can't have more systems */
310 for (sys_count = 0; sys_count < rank; sys_count++)
312 if (sys_count >= valid_systems_)
314 resize (sys_count + 3);
316 if (!isinf (st.at (brk, sys_count).details_.force_))
317 return sys_count + 1;
319 /* no possible breaks satisfy constraints */
324 Constrained_breaking::max_system_count (vsize start, vsize end)
326 vsize brk = (end >= start_.size ()) ? breaks_.size () - 1 : starting_breakpoints_[end];
327 return brk - starting_breakpoints_[start];
331 Constrained_breaking::prepare_solution (vsize start, vsize end, vsize sys_count)
333 assert (start < start_.size () && (end == VPOS || end <= start_.size ()));
334 assert (start < end);
337 if (end == start_.size ())
341 brk = end == VPOS ? breaks_.size () - 1 : starting_breakpoints_[end];
342 brk -= starting_breakpoints_[start];
346 Constrained_breaking::Constrained_breaking (Paper_score *ps)
348 valid_systems_ = systems_ = 0;
349 start_.push_back (0);
354 Constrained_breaking::Constrained_breaking (Paper_score *ps, vector<vsize> const &start)
357 valid_systems_ = systems_ = 0;
363 min_permission (SCM perm1, SCM perm2)
365 if (perm1 == ly_symbol2scm ("force"))
367 if (perm1 == ly_symbol2scm ("allow")
368 && perm2 != ly_symbol2scm ("force"))
373 /* find the forces for all possible lines and cache ragged_ and ragged_right_ */
375 Constrained_breaking::initialize ()
380 ragged_right_ = to_boolean (pscore_->layout ()->c_variable ("ragged-right"));
381 ragged_last_ = to_boolean (pscore_->layout ()->c_variable ("ragged-last"));
382 system_system_space_ = 0;
383 system_markup_space_ = 0;
384 system_system_padding_ = 0;
385 system_system_min_distance_ = 0;
386 score_system_padding_ = 0;
387 score_system_min_distance_ = 0;
388 score_markup_padding_ = 0;
389 score_markup_min_distance_ = 0;
391 Output_def *l = pscore_->layout ();
393 SCM spacing_spec = l->c_variable ("system-system-spacing");
394 SCM between_scores_spec = l->c_variable ("score-system-spacing");
395 SCM title_spec = l->c_variable ("score-markup-spacing");
396 SCM page_breaking_spacing_spec = l->c_variable ("page-breaking-system-system-spacing");
398 Page_layout_problem::read_spacing_spec (spacing_spec,
399 &system_system_space_,
400 ly_symbol2scm ("basic-distance"));
401 Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec,
402 &system_system_space_,
403 ly_symbol2scm ("basic-distance"));
404 Page_layout_problem::read_spacing_spec (title_spec,
405 &system_markup_space_,
406 ly_symbol2scm ("basic-distance"));
408 Page_layout_problem::read_spacing_spec (spacing_spec,
409 &system_system_padding_,
410 ly_symbol2scm ("padding"));
411 Page_layout_problem::read_spacing_spec (between_scores_spec,
412 &score_system_padding_,
413 ly_symbol2scm ("padding"));
414 Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec,
415 &system_system_padding_,
416 ly_symbol2scm ("padding"));
417 Page_layout_problem::read_spacing_spec (title_spec,
418 &score_markup_padding_,
419 ly_symbol2scm ("padding"));
421 Page_layout_problem::read_spacing_spec (between_scores_spec,
422 &score_system_min_distance_,
423 ly_symbol2scm ("minimum-distance"));
424 Page_layout_problem::read_spacing_spec (spacing_spec,
425 &system_system_min_distance_,
426 ly_symbol2scm ("minimum-distance"));
427 Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec,
428 &system_system_min_distance_,
429 ly_symbol2scm ("minimum-distance"));
430 Page_layout_problem::read_spacing_spec (title_spec,
431 &score_markup_min_distance_,
432 ly_symbol2scm ("minimum-distance"));
434 Interval first_line = line_dimensions_int (pscore_->layout (), 0);
435 Interval other_lines = line_dimensions_int (pscore_->layout (), 1);
436 /* do all the rod/spring problems */
437 breaks_ = pscore_->get_break_indices ();
438 all_ = pscore_->root_system ()->used_columns ();
439 lines_.resize (breaks_.size (), breaks_.size (), Line_details ());
440 vector<Real> forces = get_line_forces (all_,
441 other_lines.length (),
442 other_lines.length () - first_line.length (),
444 for (vsize i = 0; i + 1 < breaks_.size (); i++)
446 for (vsize j = i + 1; j < breaks_.size (); j++)
448 bool last = j == breaks_.size () - 1;
449 bool ragged = ragged_right_ || (last && ragged_last_);
450 Line_details &line = lines_.at (j, i);
452 line.force_ = forces[i*breaks_.size () + j];
453 if (ragged && last && !isinf (line.force_))
454 line.force_ = (line.force_ < 0 && j > i + 1) ? infinity_f : 0;
455 if (isinf (line.force_))
458 fill_line_details (&line, i, j);
462 /* work out all the starting indices */
463 for (vsize i = 0; i < start_.size (); i++)
466 for (j = 0; j + 1 < breaks_.size () && breaks_[j] < start_[i]; j++)
468 starting_breakpoints_.push_back (j);
469 start_[i] = breaks_[j];
471 state_.resize (start_.size ());
475 Fills out all of the information contained in a Line_details,
476 except for information about horizontal spacing.
479 Constrained_breaking::fill_line_details (Line_details *const out, vsize start, vsize end)
481 int start_rank = Paper_column::get_rank (all_[breaks_[start]]);
482 int end_rank = Paper_column::get_rank (all_[breaks_[end]]);
483 System *sys = pscore_->root_system ();
484 Interval begin_of_line_extent = sys->begin_of_line_pure_height (start_rank, end_rank);
485 Interval rest_of_line_extent = sys->rest_of_line_pure_height (start_rank, end_rank);
486 bool last = (end == breaks_.size () - 1);
488 Grob *c = all_[breaks_[end]];
489 out->last_column_ = c;
490 out->break_penalty_ = robust_scm2double (c->get_property ("line-break-penalty"), 0);
491 out->page_penalty_ = robust_scm2double (c->get_property ("page-break-penalty"), 0);
492 out->turn_penalty_ = robust_scm2double (c->get_property ("page-turn-penalty"), 0);
493 out->break_permission_ = c->get_property ("line-break-permission");
494 out->page_permission_ = c->get_property ("page-break-permission");
495 out->turn_permission_ = c->get_property ("page-turn-permission");
497 /* turn permission should always be stricter than page permission
498 and page permission should always be stricter than line permission */
499 out->page_permission_ = min_permission (out->break_permission_,
500 out->page_permission_);
501 out->turn_permission_ = min_permission (out->page_permission_,
502 out->turn_permission_);
504 begin_of_line_extent = (begin_of_line_extent.is_empty ()
505 || isnan (begin_of_line_extent[LEFT])
506 || isnan (begin_of_line_extent[RIGHT]))
507 ? Interval (0, 0) : begin_of_line_extent;
508 rest_of_line_extent = (rest_of_line_extent.is_empty ()
509 || isnan (rest_of_line_extent[LEFT])
510 || isnan (rest_of_line_extent[RIGHT]))
511 ? Interval (0, 0) : rest_of_line_extent;
512 out->shape_ = Line_shape (begin_of_line_extent, rest_of_line_extent);
513 out->padding_ = last ? score_system_padding_ : system_system_padding_;
514 out->title_padding_ = score_markup_padding_;
515 out->min_distance_ = last ? score_system_min_distance_ : system_system_min_distance_;
516 out->title_min_distance_ = score_markup_min_distance_;
517 out->space_ = system_system_space_;
518 out->title_space_ = system_markup_space_;
519 out->inverse_hooke_ = out->full_height () + system_system_space_;
521 out->footnotes_ = sys->get_footnotes_in_range (start_rank, end_rank);
523 out->refpoint_extent_ = sys->pure_refpoint_extent (start_rank, end_rank);
524 if (out->refpoint_extent_.is_empty ())
525 out->refpoint_extent_ = Interval (0, 0);
529 Constrained_breaking::combine_demerits (Real force, Real prev_force)
532 return force * force;
534 return force * force + (prev_force - force) * (prev_force - force);
537 Line_details::Line_details (Prob *pb, Output_def *paper)
539 SCM spec = paper->c_variable ("markup-system-spacing");
540 SCM title_spec = paper->c_variable ("markup-markup-spacing");
544 title_min_distance_ = 0;
547 Page_layout_problem::read_spacing_spec (spec, &space_, ly_symbol2scm ("basic-distance"));
548 Page_layout_problem::read_spacing_spec (title_spec, &title_space_, ly_symbol2scm ("basic-distance"));
549 Page_layout_problem::read_spacing_spec (spec, &padding_, ly_symbol2scm ("padding"));
550 Page_layout_problem::read_spacing_spec (title_spec, &title_padding_, ly_symbol2scm ("padding"));
551 Page_layout_problem::read_spacing_spec (spec, &min_distance_, ly_symbol2scm ("minimum-distance"));
552 Page_layout_problem::read_spacing_spec (title_spec, &title_min_distance_, ly_symbol2scm ("minimum-distance"));
554 SCM footnotes = pb->get_property ("footnotes");
555 if (scm_is_pair (footnotes))
556 for (SCM s = footnotes; scm_is_pair (s); s = scm_cdr (s))
557 footnotes_.push_back (unsmob_stencil (scm_car (s)));
561 Interval stencil_extent = unsmob_stencil (pb->get_property ("stencil"))->extent (Y_AXIS);
562 shape_ = Line_shape (stencil_extent, stencil_extent); // pretend it goes all the way across
565 inverse_hooke_ = 1.0;
566 break_permission_ = ly_symbol2scm ("allow");
567 page_permission_ = pb->get_property ("page-break-permission");
568 turn_permission_ = pb->get_property ("page-turn-permission");
570 page_penalty_ = robust_scm2double (pb->get_property ("page-break-penalty"), 0);
571 turn_penalty_ = robust_scm2double (pb->get_property ("page-turn-penalty"), 0);
572 title_ = to_boolean (pb->get_property ("is-title"));
573 compressed_lines_count_ = 1;
574 compressed_nontitle_lines_count_ = title_ ? 0 : 1;
575 SCM last_scm = pb->get_property ("last-markup-line");
576 last_markup_line_ = to_boolean (last_scm);
577 SCM first_scm = pb->get_property ("first-markup-line");
578 first_markup_line_ = to_boolean (first_scm);
579 tight_spacing_ = to_boolean (pb->get_property ("tight-spacing"));
580 refpoint_extent_ = Interval (0, 0);
584 Line_details::full_height () const
587 ret.unite(shape_.begin_);
588 ret.unite(shape_.rest_);
593 Line_details::tallness () const
599 Line_details::spring_length (Line_details const &next_line) const
601 // space_ measures the spring which goes from the bottom refpoint
602 // of this to the top refpoint of next_line. We want to return
603 // the stretchable space between the bottom of this's extent to
604 // the top of next_line's extent.
605 Real refpoint_dist = tallness_ + refpoint_extent_[DOWN] - next_line.refpoint_extent_[UP];
606 Real space = next_line.title_ ? title_space_ : space_;
607 return max (0.0, space - refpoint_dist);
610 Line_shape::Line_shape (Interval begin, Interval rest)
617 Line_shape::piggyback (Line_shape mount, Real padding) const
619 Real elevation = max (begin_[UP]-mount.begin_[DOWN], rest_[UP]-mount.rest_[DOWN]);
620 Interval begin = Interval (begin_[DOWN], elevation + mount.begin_[UP] + padding);
621 Interval rest = Interval (rest_[DOWN], elevation + mount.rest_[UP] + padding);
622 return Line_shape (begin, rest);