2 This file is part of LilyPond, the GNU music typesetter.
4 Copyright (C) 2009--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 "page-layout-problem.hh"
22 #include "align-interface.hh"
23 #include "axis-group-interface.hh"
24 #include "hara-kiri-group-spanner.hh"
25 #include "international.hh"
27 #include "output-def.hh"
28 #include "paper-book.hh"
29 #include "paper-column.hh"
30 #include "paper-score.hh"
31 #include "pointer-group-interface.hh"
33 #include "skyline-pair.hh"
35 #include "text-interface.hh"
38 Returns a stencil for the footnote of each system. This stencil may
39 itself be comprised of several footnotes.
43 Page_layout_problem::get_footnotes_from_lines (SCM lines, Real padding)
45 SCM footnotes = SCM_EOL;
46 // ugh...code dup from the Page_layout_problem constructor
47 for (SCM s = lines; scm_is_pair (s); s = scm_cdr (s))
49 if (Grob *g = unsmob_grob (scm_car (s)))
51 System *sys = dynamic_cast<System *> (g);
54 programming_error ("got a grob for footnotes that wasn't a System");
57 footnotes = scm_cons (sys->make_footnote_stencil (padding).smobbed_copy (), footnotes);
59 else if (Prob *p = unsmob_prob (scm_car (s)))
61 SCM stencils = p->get_property ("footnotes");
62 if (stencils == SCM_EOL)
64 Stencil footnote_stencil;
66 for (SCM st = stencils; scm_is_pair (st); st = scm_cdr (st))
67 footnote_stencil.add_at_edge (Y_AXIS, DOWN, *unsmob_stencil (scm_car (st)), padding);
68 footnotes = scm_cons (footnote_stencil.smobbed_copy (), footnotes);
72 if (!scm_is_pair (footnotes))
75 return scm_reverse (footnotes);
79 Page_layout_problem::get_footnote_separator_stencil (Output_def *paper)
81 SCM props = scm_call_1 (ly_lily_module_constant ("layout-extract-page-properties"),
84 SCM markup = paper->c_variable ("footnote-separator-markup");
86 if (!Text_interface::is_markup (markup))
89 SCM footnote_stencil = Text_interface::interpret_markup (paper->self_scm (),
92 Stencil *footnote_separator = unsmob_stencil (footnote_stencil);
94 return footnote_separator;
98 Page_layout_problem::add_footnotes_to_footer (SCM footnotes, Stencil *foot, Paper_book *pb)
100 bool footnotes_found = false;
101 Real footnote_padding = robust_scm2double (pb->paper_->c_variable ("footnote-padding"), 0.0);
102 Real footnote_footer_padding = robust_scm2double (pb->paper_->c_variable ("footnote-footer-padding"), 0.0);
104 footnotes = scm_reverse (footnotes);
106 for (SCM s = footnotes; scm_is_pair (s); s = scm_cdr (s))
108 Stencil *stencil = unsmob_stencil (scm_car (s));
113 if (!stencil->is_empty ())
115 foot->add_at_edge (Y_AXIS, UP, *stencil, (!footnotes_found ? footnote_footer_padding : footnote_padding));
116 footnotes_found = true;
122 Stencil *separator = get_footnote_separator_stencil (pb->paper_);
124 foot->add_at_edge (Y_AXIS, UP, *separator, footnote_padding);
128 Page_layout_problem::Page_layout_problem (Paper_book *pb, SCM page_scm, SCM systems)
129 : bottom_skyline_ (DOWN)
131 Prob *page = unsmob_prob (page_scm);
140 Stencil *head = unsmob_stencil (page->get_property ("head-stencil"));
141 Stencil *foot = unsmob_stencil (page->get_property ("foot-stencil"));
143 Real footnote_padding = 0.0;
144 if (pb && pb->paper_)
145 footnote_padding = robust_scm2double (pb->paper_->c_variable ("footnote-padding"), 0.0);
146 SCM footnotes = get_footnotes_from_lines (systems, footnote_padding);
147 add_footnotes_to_footer (footnotes, foot, pb);
149 header_height_ = head ? head->extent (Y_AXIS).length () : 0;
150 footer_height_ = foot ? foot->extent (Y_AXIS).length () : 0;
151 page_height_ = robust_scm2double (page->get_property ("paper-height"), 100);
154 // Initially, bottom_skyline_ represents the top of the page. Make
155 // it solid, so that the top of the first system will be forced
156 // below the top of the printable area.
157 bottom_skyline_.set_minimum_height (-header_height_);
159 SCM system_system_spacing = SCM_EOL;
160 SCM score_system_spacing = SCM_EOL;
161 SCM markup_system_spacing = SCM_EOL;
162 SCM score_markup_spacing = SCM_EOL;
163 SCM markup_markup_spacing = SCM_EOL;
165 // top_system_spacing controls the spring from the top of the printable
166 // area to the first staff. It allows the user to control the offset of
167 // the first staff (as opposed to the top of the first system) from the
168 // top of the page. Similarly for last_bottom_spacing.
169 SCM top_system_spacing = SCM_EOL;
170 SCM last_bottom_spacing = SCM_EOL;
171 if (pb && pb->paper_)
173 Output_def *paper = pb->paper_;
174 system_system_spacing = paper->c_variable ("system-system-spacing");
175 score_system_spacing = paper->c_variable ("score-system-spacing");
176 markup_system_spacing = paper->c_variable ("markup-system-spacing");
177 score_markup_spacing = paper->c_variable ("score-markup-spacing");
178 markup_markup_spacing = paper->c_variable ("markup-markup-spacing");
179 last_bottom_spacing = paper->c_variable ("last-bottom-spacing");
180 top_system_spacing = paper->c_variable ("top-system-spacing");
181 if (scm_is_pair (systems) && unsmob_prob (scm_car (systems)))
182 top_system_spacing = paper->c_variable ("top-markup-spacing");
184 // Note: the page height here does _not_ reserve space for headers and
185 // footers. This is because we want to anchor the top-system-spacing
186 // spring at the _top_ of the header.
187 page_height_ -= robust_scm2double (paper->c_variable ("top-margin"), 0)
188 + robust_scm2double (paper->c_variable ("bottom-margin"), 0);
190 read_spacing_spec (top_system_spacing, &header_padding_, ly_symbol2scm ("padding"));
191 read_spacing_spec (last_bottom_spacing, &footer_padding_, ly_symbol2scm ("padding"));
193 bool last_system_was_title = false;
196 for (SCM s = systems; scm_is_pair (s); s = scm_cdr (s))
198 bool first = (s == systems);
200 if (Grob *g = unsmob_grob (scm_car (s)))
202 System *sys = dynamic_cast<System*> (g);
205 programming_error ("got a grob for vertical spacing that wasn't a System");
209 SCM spec = system_system_spacing;
211 spec = top_system_spacing;
212 else if (last_system_was_title)
213 spec = markup_system_spacing;
214 else if (0 == Paper_column::get_rank (sys->get_bound (LEFT)))
215 spec = score_system_spacing;
217 Spring spring (0, 0);
219 Real indent = line_dimensions_int (sys->paper_score ()->layout (), sys->get_rank ())[LEFT];
220 alter_spring_from_spacing_spec (spec, &spring);
221 read_spacing_spec (spec, &padding, ly_symbol2scm ("padding"));
223 append_system (sys, spring, indent, padding);
224 last_system_was_title = false;
226 else if (Prob *p = unsmob_prob (scm_car (s)))
228 SCM spec = first ? top_system_spacing
229 : (last_system_was_title ? markup_markup_spacing : score_markup_spacing);
230 Spring spring (0, 0);
232 alter_spring_from_spacing_spec (spec, &spring);
233 read_spacing_spec (spec, &padding, ly_symbol2scm ("padding"));
235 append_prob (p, spring, padding);
236 last_system_was_title = true;
239 programming_error ("got a system that was neither a Grob nor a Prob");
242 Spring last_spring (0, 0);
243 Real last_padding = 0;
244 alter_spring_from_spacing_spec (last_bottom_spacing, &last_spring);
245 read_spacing_spec (last_bottom_spacing, &last_padding, ly_symbol2scm ("padding"));
246 last_spring.ensure_min_distance (last_padding - bottom_skyline_.max_height () + footer_height_);
247 springs_.push_back (last_spring);
249 if (elements_.size ())
251 Real bottom_padding = 0;
253 // TODO: junk bottom-space now that we have last-bottom-spacing?
254 // bottom-space has the flexibility that one can do it per-system.
255 // NOTE: bottom-space is misnamed since it is not stretchable space.
256 if (Prob *p = elements_.back ().prob)
257 bottom_padding = robust_scm2double (p->get_property ("bottom-space"), 0);
258 else if (elements_.back ().staves.size ())
260 SCM details = get_details (elements_.back ());
261 bottom_padding = robust_scm2double (ly_assoc_get (ly_symbol2scm ("bottom-space"),
266 page_height_ -= bottom_padding;
271 Page_layout_problem::set_header_height (Real height)
273 header_height_ = height;
277 Page_layout_problem::set_footer_height (Real height)
279 footer_height_ = height;
283 Page_layout_problem::append_system (System *sys, Spring const& spring, Real indent, Real padding)
285 Grob *align = sys->get_vertical_alignment ();
289 align->set_property ("positioning-done", SCM_BOOL_T);
291 extract_grob_set (align, "elements", all_elts);
292 vector<Grob*> elts = filter_dead_elements (all_elts);
293 vector<Real> minimum_offsets = Align_interface::get_minimum_translations_without_min_dist (align, elts, Y_AXIS);
294 vector<Real> minimum_offsets_with_min_dist = Align_interface::get_minimum_translations (align, elts, Y_AXIS);
296 Skyline up_skyline (UP);
297 Skyline down_skyline (DOWN);
298 build_system_skyline (elts, minimum_offsets_with_min_dist, &up_skyline, &down_skyline);
299 up_skyline.shift (indent);
300 down_skyline.shift (indent);
303 We need to call distance with skyline-horizontal-padding because
304 the system skyline-horizontal-padding is not added during the creation
305 of an individual staff. So we add the padding for the distance check
306 at the time of adding in the system.
308 Real minimum_distance = up_skyline.distance (bottom_skyline_, robust_scm2double (sys->get_property ("skyline-horizontal-padding"), 0)) + padding;
310 Spring spring_copy = spring;
311 spring_copy.ensure_min_distance (minimum_distance);
312 springs_.push_back (spring_copy);
314 bottom_skyline_ = down_skyline;
315 elements_.push_back (Element (elts, minimum_offsets));
317 // Add the springs for the VerticalAxisGroups in this system.
319 // If the user has specified the offsets of the individual staves, fix the
320 // springs at the given distances. Otherwise, use stretchable springs.
321 SCM details = get_details (elements_.back ());
322 SCM manual_dists = ly_assoc_get (ly_symbol2scm ("alignment-distances"), details, SCM_EOL);
323 vsize last_spaceable_staff = 0;
324 bool found_spaceable_staff = false;
325 for (vsize i = 0; i < elts.size (); ++i)
327 if (is_spaceable (elts[i]))
329 // We don't add a spring for the first staff, since
330 // we are only adding springs _between_ staves here.
331 if (!found_spaceable_staff)
333 found_spaceable_staff = true;
334 last_spaceable_staff = i;
338 Spring spring (0.5, 0.0);
339 SCM spec = elts[last_spaceable_staff]->get_property ("staff-staff-spacing");
340 alter_spring_from_spacing_spec (spec, &spring);
342 springs_.push_back (spring);
343 Real min_distance = (found_spaceable_staff ? minimum_offsets[last_spaceable_staff] : 0) - minimum_offsets[i];
344 springs_.back ().ensure_min_distance (min_distance);
346 if (scm_is_pair (manual_dists))
348 if (scm_is_number (scm_car (manual_dists)))
350 Real dy = scm_to_double (scm_car (manual_dists));
352 springs_.back ().set_distance (dy);
353 springs_.back ().set_min_distance (dy);
354 springs_.back ().set_inverse_stretch_strength (0);
356 manual_dists = scm_cdr (manual_dists);
358 last_spaceable_staff = i;
362 // Corner case: there was only one staff, and it wasn't spaceable.
363 // Mark it spaceable, because we do not allow non-spaceable staves
364 // to be at the top or bottom of a system.
365 if (!found_spaceable_staff && elts.size ())
366 mark_as_spaceable (elts[0]);
370 Page_layout_problem::append_prob (Prob *prob, Spring const& spring, Real padding)
372 Skyline_pair *sky = Skyline_pair::unsmob (prob->get_property ("vertical-skylines"));
373 Real minimum_distance = 0;
374 bool tight_spacing = to_boolean (prob->get_property ("tight-spacing"));
378 minimum_distance = (*sky)[UP].distance (bottom_skyline_);
379 bottom_skyline_ = (*sky)[DOWN];
381 else if (Stencil *sten = unsmob_stencil (prob->get_property ("stencil")))
383 Interval iv = sten->extent (Y_AXIS);
384 minimum_distance = iv[UP] - bottom_skyline_.max_height ();
386 bottom_skyline_.clear ();
387 bottom_skyline_.set_minimum_height (iv[DOWN]);
390 Spring spring_copy = spring;
393 spring_copy.set_min_distance (minimum_distance);
394 spring_copy.set_inverse_stretch_strength (0.0);
395 spring_copy.set_distance (0.0);
398 spring_copy.ensure_min_distance (minimum_distance + padding);
400 springs_.push_back (spring_copy);
401 elements_.push_back (Element (prob));
405 Page_layout_problem::solve_rod_spring_problem (bool ragged)
407 Simple_spacer spacer;
409 for (vsize i = 0; i < springs_.size (); ++i)
410 spacer.add_spring (springs_[i]);
412 spacer.solve (page_height_, ragged);
413 solution_ = spacer.spring_positions ();
417 Real overflow = spacer.configuration_length (spacer.force ())
419 if (ragged && overflow < 1e-6)
420 warning (_ ("cannot fit music on page: ragged-spacing was requested, but page was compressed"));
423 warning (_f ("cannot fit music on page: overflow is %f",
425 warning (_ ("compressing music to fit"));
426 vsize space_count = solution_.size ();
427 Real spacing_increment = overflow / (space_count - 2);
428 for (vsize i = 2; i < space_count; i++)
429 solution_[i] -= (i-1) * spacing_increment;
434 // The solution_ vector stores the position of every live VerticalAxisGroup
435 // and every title. From that information,
436 // 1) within each system, stretch the staves so they land at the right position
437 // 2) find the offset of each system (relative to the printable area of the page).
438 // TODO: this function is getting too long, maybe split it up?
440 Page_layout_problem::find_system_offsets ()
442 SCM system_offsets = SCM_EOL;
443 SCM *tail = &system_offsets;
445 // spring_idx 0 is the top of the page. Interesting values start from 1.
446 vsize spring_idx = 1;
447 vector<Grob*> loose_lines;
448 vector<Real> loose_line_min_distances;
449 Grob *last_spaceable_line = 0;
450 Real last_spaceable_line_translation = 0;
451 Interval last_title_extent;
452 for (vsize i = 0; i < elements_.size (); ++i)
454 if (elements_[i].prob)
456 *tail = scm_cons (scm_from_double (solution_[spring_idx]), SCM_EOL);
457 tail = SCM_CDRLOC (*tail);
458 Interval prob_extent = unsmob_stencil (elements_[i].prob->get_property ("stencil"))->extent (Y_AXIS);
460 // Lay out any non-spaceable lines between this line and
462 if (loose_lines.size ())
464 Interval loose_extent = loose_lines.back ()->extent (loose_lines.back (), Y_AXIS);
465 Real min_distance = -loose_extent[DOWN] + prob_extent[UP]; // TODO: include padding/minimum-distance
467 loose_line_min_distances.push_back (min_distance);
468 loose_lines.push_back (0);
470 distribute_loose_lines (loose_lines, loose_line_min_distances,
471 last_spaceable_line_translation, -solution_[spring_idx]);
472 loose_lines.clear ();
473 loose_line_min_distances.clear ();
476 last_spaceable_line = 0;
477 last_spaceable_line_translation = -solution_[spring_idx];
478 last_title_extent = prob_extent;
483 // Getting this signs right here is a little tricky. The configuration
484 // we return has zero at the top of the page and positive numbers further
485 // down, as does the solution_ vector. Within a staff, however, positive
487 // TODO: perhaps change the way the page 'configuration variable works so
488 // that it is consistent with the usual up/down sign conventions in
489 // Lilypond. Then this would be less confusing.
491 // These two positions are relative to the page (with positive numbers being
493 Real first_staff_position = solution_[spring_idx];
494 Real first_staff_min_translation = elements_[i].min_offsets.size () ? elements_[i].min_offsets[0] : 0;
495 Real system_position = first_staff_position + first_staff_min_translation;
497 // Position the staves within this system.
498 Real translation = 0;
499 vector<Real> const& min_offsets = elements_[i].min_offsets;
500 bool found_spaceable_staff = false;
501 for (vsize staff_idx = 0; staff_idx < elements_[i].staves.size (); ++staff_idx)
503 Grob *staff = elements_[i].staves[staff_idx];
504 staff->set_property ("system-Y-offset", scm_from_double (-system_position));
506 if (is_spaceable (staff))
508 // this is relative to the system: negative numbers are down.
509 translation = system_position - solution_[spring_idx];
512 // Lay out any non-spaceable lines between this line and
514 if (loose_lines.size ())
516 loose_line_min_distances.push_back (min_offsets[staff_idx-1] - min_offsets[staff_idx]);
517 loose_lines.push_back (staff);
519 distribute_loose_lines (loose_lines, loose_line_min_distances,
520 last_spaceable_line_translation, translation - system_position);
521 loose_lines.clear ();
522 loose_line_min_distances.clear ();
524 last_spaceable_line = staff;
525 // Negative is down but the translation is relative to the whole page.
526 last_spaceable_line_translation = -system_position + translation;
528 staff->translate_axis (translation, Y_AXIS);
529 found_spaceable_staff = true;
533 if (loose_lines.empty ())
534 loose_lines.push_back (last_spaceable_line);
537 loose_line_min_distances.push_back (min_offsets[staff_idx-1] - min_offsets[staff_idx]);
541 if (loose_lines.back ())
542 min_dist = Axis_group_interface::minimum_distance (loose_lines.back (),
545 else if (!last_title_extent.is_empty ())
546 { // distance to the preceding title
547 // TODO: add options for controlling the space between a loose line
548 // and a title/markup preceding it.
549 min_dist = staff->extent (staff, Y_AXIS)[UP] - last_title_extent[DOWN];
551 else // distance to the top margin
552 min_dist = header_padding_ + header_height_ + staff->extent (staff, Y_AXIS)[UP];
554 loose_line_min_distances.push_back (min_dist);
556 loose_lines.push_back (staff);
560 // Corner case: even if a system has no live staves, it still takes up
561 // one spring (a system with one live staff also takes up one spring),
562 // which we need to increment past.
563 if (!found_spaceable_staff)
566 *tail = scm_cons (scm_from_double (system_position), SCM_EOL);
567 tail = SCM_CDRLOC (*tail);
571 if (loose_lines.size ())
573 Grob *last = loose_lines.back ();
574 Interval last_ext = last->extent (last, Y_AXIS);
575 loose_line_min_distances.push_back (-last_ext[DOWN] + footer_height_ + footer_padding_);
576 loose_lines.push_back (0);
578 distribute_loose_lines (loose_lines, loose_line_min_distances,
579 last_spaceable_line_translation, -page_height_);
583 assert (spring_idx == solution_.size () - 1);
584 return system_offsets;
587 // Given two lines that are already spaced (the first and last
588 // elements of loose_lines), distribute some unspaced lines between
590 // first_translation and last_translation are relative to the page.
592 Page_layout_problem::distribute_loose_lines (vector<Grob*> const &loose_lines,
593 vector<Real> const &min_distances,
594 Real first_translation, Real last_translation)
596 Simple_spacer spacer;
597 for (vsize i = 0; i + 1 < loose_lines.size (); ++i)
599 SCM spec = get_spacing_spec (loose_lines[i], loose_lines[i+1], false, 0, INT_MAX);
600 Spring spring (1.0, 0.0);
601 alter_spring_from_spacing_spec (spec, &spring);
602 spring.ensure_min_distance (min_distances[i]);
603 spacer.add_spring (spring);
606 // Remember: offsets are decreasing, since we're going from UP to DOWN!
607 spacer.solve (first_translation - last_translation, false);
609 vector<Real> solution = spacer.spring_positions ();
610 for (vsize i = 1; i + 1 < solution.size (); ++i)
612 Real system_offset = scm_to_double (loose_lines[i]->get_property ("system-Y-offset"));
613 loose_lines[i]->translate_axis (first_translation - solution[i] - system_offset, Y_AXIS);
618 Page_layout_problem::solution (bool ragged)
620 solve_rod_spring_problem (ragged);
621 return find_system_offsets ();
624 // Build upper and lower skylines for a system. We don't yet know the positions
625 // of the staves within the system, so we make the skyline as conservative as
626 // possible. That is, for the upper skyline, we pretend that all of the staves
627 // in the system are packed together close to the top system; for the lower
628 // skyline, we pretend that all of the staves are packed together close to
629 // the bottom system.
631 // The upper skyline is relative to the top staff; the lower skyline is relative to
634 Page_layout_problem::build_system_skyline (vector<Grob*> const& staves,
635 vector<Real> const& minimum_translations,
639 if (minimum_translations.empty ())
642 assert (staves.size () == minimum_translations.size ());
643 Real first_translation = minimum_translations[0];
644 Real last_spaceable_dy = 0;
645 Real first_spaceable_dy = 0;
646 bool found_spaceable_staff = false;
648 for (vsize i = 0; i < staves.size (); ++i)
650 Real dy = minimum_translations[i] - first_translation;
652 Skyline_pair *sky = Skyline_pair::unsmob (g->get_property ("vertical-skylines"));
656 up->merge ((*sky)[UP]);
660 down->merge ((*sky)[DOWN]);
663 if (is_spaceable (staves[i]))
665 if (!found_spaceable_staff)
667 found_spaceable_staff = true;
668 first_spaceable_dy = dy;
670 last_spaceable_dy = dy;
674 // Leave the up skyline at a position relative
675 // to the top spaceable staff.
676 up->raise (-first_spaceable_dy);
678 // Leave the down skyline at a position
679 // relative to the bottom spaceable staff.
680 down->raise (-last_spaceable_dy);
684 Page_layout_problem::prob_extent (Prob *p)
686 Stencil *sten = unsmob_stencil (p->get_property ("stencil"));
687 return sten ? sten->extent (Y_AXIS) : Interval (0, 0);
691 Page_layout_problem::first_staff_extent (Element const& e)
694 return prob_extent (e.prob);
695 else if (e.staves.size ())
696 return e.staves[0]->extent (e.staves[0], Y_AXIS);
698 return Interval (0, 0);
702 Page_layout_problem::last_staff_extent (Element const& e)
705 return prob_extent (e.prob);
706 else if (e.staves.size ())
707 return e.staves.back ()->extent (e.staves.back (), Y_AXIS);
709 return Interval (0, 0);
713 Page_layout_problem::get_details (Element const& elt)
715 if (elt.staves.empty ())
718 return get_details (elt.staves.back ()->get_system ());
722 Page_layout_problem::get_details (Grob *g)
724 Grob *left_bound = dynamic_cast<Spanner*> (g)->get_bound (LEFT);
725 return left_bound->get_property ("line-break-system-details");
729 Page_layout_problem::is_spaceable (Grob *g)
731 return !scm_is_number (g->get_property ("staff-affinity"));
735 Page_layout_problem::mark_as_spaceable (Grob *g)
737 g->set_property ("staff-affinity", SCM_BOOL_F);
741 Page_layout_problem::read_spacing_spec (SCM spec, Real* dest, SCM sym)
743 SCM pair = scm_sloppy_assq (sym, spec);
744 if (scm_is_pair (pair) && scm_is_number (scm_cdr (pair)))
746 *dest = scm_to_double (scm_cdr (pair));
752 // If there is a forced, fixed spacing between BEFORE and AFTER, return it.
753 // Otherwise, return -infinity_f.
754 // If after is spaceable, it is the (spaceable_index + 1)th spaceable grob in
757 Page_layout_problem::get_fixed_spacing (Grob *before, Grob *after, int spaceable_index, bool pure, int start, int end)
759 Spanner *after_sp = dynamic_cast<Spanner*> (after);
760 SCM cache_symbol = (is_spaceable (before) && is_spaceable (after))
761 ? ly_symbol2scm ("spaceable-fixed-spacing")
762 : ly_symbol2scm ("loose-fixed-spacing");
765 // The result of this function doesn't depend on "end," so we can reduce the
766 // size of the cache by ignoring it.
767 SCM cached = after_sp->get_cached_pure_property (cache_symbol, start, 0);
768 if (scm_is_number (cached))
769 return robust_scm2double (cached, 0.0);
772 SCM spec = Page_layout_problem::get_spacing_spec (before, after, pure, start, end);
773 Real ret = -infinity_f;
774 Real stretchability = 0;
775 if (Page_layout_problem::read_spacing_spec (spec, &stretchability, ly_symbol2scm ("stretchability"))
776 && stretchability == 0)
777 Page_layout_problem::read_spacing_spec (spec, &ret, ly_symbol2scm ("basic-distance"));
779 // If we're pure, then paper-columns have not had their systems set,
780 // and so elts[i]->get_system () is unreliable.
781 System *sys = pure ? Grob::get_system (before) : before->get_system ();
782 Grob *left_bound = sys ? sys->get_maybe_pure_bound (LEFT, pure, start, end) : 0;
784 if (is_spaceable (before) && is_spaceable (after) && left_bound)
786 SCM details = left_bound->get_property ("line-break-system-details");
787 SCM manual_dists = ly_assoc_get (ly_symbol2scm ("alignment-distances"), details, SCM_EOL);
788 if (scm_is_pair (manual_dists))
790 SCM forced = robust_list_ref (spaceable_index - 1, manual_dists);
791 if (scm_is_number (forced))
792 ret = max (ret, scm_to_double (forced));
796 // Cache the result. As above, we ignore "end."
798 after_sp->cache_pure_property (cache_symbol, start, 0, scm_from_double (ret));
804 add_stretchability (SCM alist, Real stretch)
806 if (!scm_is_pair (scm_sloppy_assq (ly_symbol2scm ("stretchability"), alist)))
807 return scm_acons (ly_symbol2scm ("stretchability"), scm_from_double (stretch), alist);
812 // We want to put a large stretch between a non-spaceable line and its
813 // non-affinity staff. We want to put an even larger stretch between
814 // a non-spaceable line and the top/bottom of the page. That way,
815 // a spacing-affinity UP line at the bottom of the page will still be
816 // placed close to its staff.
817 const double LARGE_STRETCH = 10e5;
818 const double HUGE_STRETCH = 10e7;
820 // Returns the spacing spec connecting BEFORE to AFTER.
822 Page_layout_problem::get_spacing_spec (Grob *before, Grob *after, bool pure, int start, int end)
824 // If there are no spacing wishes, return a very flexible spring.
825 // This will occur, for example, if there are lyrics at the bottom of
826 // the page, in which case we don't want the spring from the lyrics to
827 // the bottom of the page to have much effect.
828 if (!before || !after)
829 return add_stretchability (SCM_EOL, HUGE_STRETCH);
831 if (is_spaceable (before))
833 if (is_spaceable (after))
834 return before->get_maybe_pure_property ("staff-staff-spacing", pure, start, end);
837 Direction affinity = to_dir (after->get_maybe_pure_property ("staff-affinity", pure, start, end));
838 return (affinity == DOWN)
839 ? add_stretchability (after->get_maybe_pure_property ("nonstaff-unrelatedstaff-spacing", pure, start, end),
841 : after->get_maybe_pure_property ("nonstaff-relatedstaff-spacing", pure, start, end);
846 if (is_spaceable (after))
848 Direction affinity = to_dir (before->get_maybe_pure_property ("staff-affinity", pure, start, end));
849 return (affinity == UP)
850 ? add_stretchability (before->get_maybe_pure_property ("nonstaff-unrelatedstaff-spacing", pure, start, end),
852 : before->get_maybe_pure_property ("nonstaff-relatedstaff-spacing", pure, start, end);
856 Direction before_affinity = to_dir (before->get_maybe_pure_property ("staff-affinity", pure, start, end));
857 Direction after_affinity = to_dir (after->get_maybe_pure_property ("staff-affinity", pure, start, end));
858 if (after_affinity > before_affinity)
860 warning (_ ("staff-affinities should only decrease"));
861 after_affinity = before_affinity;
863 if (before_affinity != UP)
864 return before->get_maybe_pure_property ("nonstaff-nonstaff-spacing", pure, start, end);
865 else if (after_affinity != DOWN)
866 return before->get_maybe_pure_property ("nonstaff-nonstaff-spacing", pure, start, end);
867 return add_stretchability (before->get_maybe_pure_property ("nonstaff-unrelatedstaff-spacing", pure, start, end),
877 Page_layout_problem::alter_spring_from_spacing_spec (SCM spec, Spring* spring)
882 if (read_spacing_spec (spec, &space, ly_symbol2scm ("basic-distance")))
883 spring->set_distance (space);
884 if (read_spacing_spec (spec, &min_dist, ly_symbol2scm ("minimum-distance")))
885 spring->set_min_distance (min_dist);
886 spring->set_default_strength ();
888 if (read_spacing_spec (spec, &stretch, ly_symbol2scm ("stretchability")))
890 spring->set_inverse_stretch_strength (stretch);
891 spring->set_inverse_compress_strength (stretch);
896 Page_layout_problem::filter_dead_elements (vector<Grob*> const& input)
898 vector<Grob*> output;
899 for (vsize i = 0; i < input.size (); ++i)
901 if (Hara_kiri_group_spanner::has_interface (input[i]))
902 Hara_kiri_group_spanner::consider_suicide (input[i]);
904 if (input[i]->is_live ())
905 output.push_back (input[i]);