X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fpage-layout-problem.cc;fp=lily%2Fpage-layout-problem.cc;h=9ee2b3fea11b9ae3a22ef74ebb140515b9224fd4;hb=e90f0536f9be39ada0bef0aeb0d275dec3b2fb5b;hp=0000000000000000000000000000000000000000;hpb=a8c9e8a7ca320ab0df5fd32e717fd62cd7635ce6;p=lilypond.git diff --git a/lily/page-layout-problem.cc b/lily/page-layout-problem.cc new file mode 100644 index 0000000000..9ee2b3fea1 --- /dev/null +++ b/lily/page-layout-problem.cc @@ -0,0 +1,917 @@ +/* + This file is part of LilyPond, the GNU music typesetter. + + Copyright (C) 2009--2011 Joe Neeman + + LilyPond is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + LilyPond is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with LilyPond. If not, see . +*/ + +#include "page-layout-problem.hh" + +#include "align-interface.hh" +#include "axis-group-interface.hh" +#include "hara-kiri-group-spanner.hh" +#include "international.hh" +#include "item.hh" +#include "output-def.hh" +#include "paper-book.hh" +#include "paper-column.hh" +#include "paper-score.hh" +#include "pointer-group-interface.hh" +#include "prob.hh" +#include "skyline-pair.hh" +#include "system.hh" +#include "text-interface.hh" + +/* + Returns a stencil for the footnote of each system. This stencil may + itself be comprised of several footnotes. +*/ + +SCM +Page_layout_problem::get_footnotes_from_lines (SCM lines, Real padding) +{ + SCM footnotes = SCM_EOL; + // ugh...code dup from the Page_layout_problem constructor + for (SCM s = lines; scm_is_pair (s); s = scm_cdr (s)) + { + if (Grob *g = unsmob_grob (scm_car (s))) + { + System *sys = dynamic_cast (g); + if (!sys) + { + programming_error ("got a grob for footnotes that wasn't a System"); + continue; + } + footnotes = scm_cons (sys->make_footnote_stencil (padding).smobbed_copy (), footnotes); + } + else if (Prob *p = unsmob_prob (scm_car (s))) + { + SCM stencils = p->get_property ("footnotes"); + if (stencils == SCM_EOL) + continue; + Stencil footnote_stencil; + + for (SCM st = stencils; scm_is_pair (st); st = scm_cdr (st)) + footnote_stencil.add_at_edge (Y_AXIS, DOWN, *unsmob_stencil (scm_car (st)), padding); + footnotes = scm_cons (footnote_stencil.smobbed_copy (), footnotes); + } + } + + if (!scm_is_pair (footnotes)) + return SCM_EOL; + + return scm_reverse (footnotes); +} + +Stencil* +Page_layout_problem::get_footnote_separator_stencil (Output_def *paper) +{ + SCM props = scm_call_1 (ly_lily_module_constant ("layout-extract-page-properties"), + paper->self_scm ()); + + SCM markup = paper->c_variable ("footnote-separator-markup"); + + if (!Text_interface::is_markup (markup)) + return NULL; + + SCM footnote_stencil = Text_interface::interpret_markup (paper->self_scm (), + props, markup); + + Stencil *footnote_separator = unsmob_stencil (footnote_stencil); + + return footnote_separator; +} + +void +Page_layout_problem::add_footnotes_to_footer (SCM footnotes, Stencil *foot, Paper_book *pb) +{ + bool footnotes_found = false; + Real footnote_padding = robust_scm2double (pb->paper_->c_variable ("footnote-padding"), 0.0); + Real footnote_footer_padding = robust_scm2double (pb->paper_->c_variable ("footnote-footer-padding"), 0.0); + + footnotes = scm_reverse (footnotes); + + for (SCM s = footnotes; scm_is_pair (s); s = scm_cdr (s)) + { + Stencil *stencil = unsmob_stencil (scm_car (s)); + + if (!stencil) + continue; + + if (!stencil->is_empty ()) + { + foot->add_at_edge (Y_AXIS, UP, *stencil, (!footnotes_found ? footnote_footer_padding : footnote_padding)); + footnotes_found = true; + } + } + + if (footnotes_found) + { + Stencil *separator = get_footnote_separator_stencil (pb->paper_); + if (separator) + foot->add_at_edge (Y_AXIS, UP, *separator, footnote_padding); + } +} + +Page_layout_problem::Page_layout_problem (Paper_book *pb, SCM page_scm, SCM systems) + : bottom_skyline_ (DOWN) +{ + Prob *page = unsmob_prob (page_scm); + header_height_ = 0; + footer_height_ = 0; + header_padding_ = 0; + footer_padding_ = 0; + page_height_ = 100; + + if (page) + { + Stencil *head = unsmob_stencil (page->get_property ("head-stencil")); + Stencil *foot = unsmob_stencil (page->get_property ("foot-stencil")); + + Real footnote_padding = 0.0; + if (pb && pb->paper_) + footnote_padding = robust_scm2double (pb->paper_->c_variable ("footnote-padding"), 0.0); + SCM footnotes = get_footnotes_from_lines (systems, footnote_padding); + add_footnotes_to_footer (footnotes, foot, pb); + + header_height_ = head ? head->extent (Y_AXIS).length () : 0; + footer_height_ = foot ? foot->extent (Y_AXIS).length () : 0; + page_height_ = robust_scm2double (page->get_property ("paper-height"), 100); + } + + // Initially, bottom_skyline_ represents the top of the page. Make + // it solid, so that the top of the first system will be forced + // below the top of the printable area. + bottom_skyline_.set_minimum_height (-header_height_); + + SCM system_system_spacing = SCM_EOL; + SCM score_system_spacing = SCM_EOL; + SCM markup_system_spacing = SCM_EOL; + SCM score_markup_spacing = SCM_EOL; + SCM markup_markup_spacing = SCM_EOL; + + // top_system_spacing controls the spring from the top of the printable + // area to the first staff. It allows the user to control the offset of + // the first staff (as opposed to the top of the first system) from the + // top of the page. Similarly for last_bottom_spacing. + SCM top_system_spacing = SCM_EOL; + SCM last_bottom_spacing = SCM_EOL; + if (pb && pb->paper_) + { + Output_def *paper = pb->paper_; + system_system_spacing = paper->c_variable ("system-system-spacing"); + score_system_spacing = paper->c_variable ("score-system-spacing"); + markup_system_spacing = paper->c_variable ("markup-system-spacing"); + score_markup_spacing = paper->c_variable ("score-markup-spacing"); + markup_markup_spacing = paper->c_variable ("markup-markup-spacing"); + last_bottom_spacing = paper->c_variable ("last-bottom-spacing"); + top_system_spacing = paper->c_variable ("top-system-spacing"); + if (scm_is_pair (systems) && unsmob_prob (scm_car (systems))) + top_system_spacing = paper->c_variable ("top-markup-spacing"); + + // Note: the page height here does _not_ reserve space for headers and + // footers. This is because we want to anchor the top-system-spacing + // spring at the _top_ of the header. + page_height_ -= robust_scm2double (paper->c_variable ("top-margin"), 0) + + robust_scm2double (paper->c_variable ("bottom-margin"), 0); + + read_spacing_spec (top_system_spacing, &header_padding_, ly_symbol2scm ("padding")); + read_spacing_spec (last_bottom_spacing, &footer_padding_, ly_symbol2scm ("padding")); + } + bool last_system_was_title = false; + + + for (SCM s = systems; scm_is_pair (s); s = scm_cdr (s)) + { + bool first = (s == systems); + + if (Grob *g = unsmob_grob (scm_car (s))) + { + System *sys = dynamic_cast (g); + if (!sys) + { + programming_error ("got a grob for vertical spacing that wasn't a System"); + continue; + } + + SCM spec = system_system_spacing; + if (first) + spec = top_system_spacing; + else if (last_system_was_title) + spec = markup_system_spacing; + else if (0 == Paper_column::get_rank (sys->get_bound (LEFT))) + spec = score_system_spacing; + + Spring spring (0, 0); + Real padding = 0.0; + Real indent = line_dimensions_int (sys->paper_score ()->layout (), sys->get_rank ())[LEFT]; + alter_spring_from_spacing_spec (spec, &spring); + read_spacing_spec (spec, &padding, ly_symbol2scm ("padding")); + + append_system (sys, spring, indent, padding); + last_system_was_title = false; + } + else if (Prob *p = unsmob_prob (scm_car (s))) + { + SCM spec = first ? top_system_spacing + : (last_system_was_title ? markup_markup_spacing : score_markup_spacing); + Spring spring (0, 0); + Real padding = 0.0; + alter_spring_from_spacing_spec (spec, &spring); + read_spacing_spec (spec, &padding, ly_symbol2scm ("padding")); + + append_prob (p, spring, padding); + last_system_was_title = true; + } + else + programming_error ("got a system that was neither a Grob nor a Prob"); + } + + Spring last_spring (0, 0); + Real last_padding = 0; + alter_spring_from_spacing_spec (last_bottom_spacing, &last_spring); + read_spacing_spec (last_bottom_spacing, &last_padding, ly_symbol2scm ("padding")); + last_spring.ensure_min_distance (last_padding - bottom_skyline_.max_height () + footer_height_); + springs_.push_back (last_spring); + + if (elements_.size ()) + { + Real bottom_padding = 0; + + // TODO: junk bottom-space now that we have last-bottom-spacing? + // bottom-space has the flexibility that one can do it per-system. + // NOTE: bottom-space is misnamed since it is not stretchable space. + if (Prob *p = elements_.back ().prob) + bottom_padding = robust_scm2double (p->get_property ("bottom-space"), 0); + else if (elements_.back ().staves.size ()) + { + SCM details = get_details (elements_.back ()); + bottom_padding = robust_scm2double (ly_assoc_get (ly_symbol2scm ("bottom-space"), + details, + SCM_BOOL_F), + 0.0); + } + page_height_ -= bottom_padding; + } +} + +void +Page_layout_problem::set_header_height (Real height) +{ + header_height_ = height; +} + +void +Page_layout_problem::set_footer_height (Real height) +{ + footer_height_ = height; +} + +void +Page_layout_problem::append_system (System *sys, Spring const& spring, Real indent, Real padding) +{ + Grob *align = sys->get_vertical_alignment (); + if (!align) + return; + + align->set_property ("positioning-done", SCM_BOOL_T); + + extract_grob_set (align, "elements", all_elts); + vector elts = filter_dead_elements (all_elts); + vector minimum_offsets = Align_interface::get_minimum_translations_without_min_dist (align, elts, Y_AXIS); + vector minimum_offsets_with_min_dist = Align_interface::get_minimum_translations (align, elts, Y_AXIS); + + Skyline up_skyline (UP); + Skyline down_skyline (DOWN); + build_system_skyline (elts, minimum_offsets_with_min_dist, &up_skyline, &down_skyline); + up_skyline.shift (indent); + down_skyline.shift (indent); + + /* + We need to call distance with skyline-horizontal-padding because + the system skyline-horizontal-padding is not added during the creation + of an individual staff. So we add the padding for the distance check + at the time of adding in the system. + */ + Real minimum_distance = up_skyline.distance (bottom_skyline_, robust_scm2double (sys->get_property ("skyline-horizontal-padding"), 0)) + padding; + + Spring spring_copy = spring; + spring_copy.ensure_min_distance (minimum_distance); + springs_.push_back (spring_copy); + + bottom_skyline_ = down_skyline; + elements_.push_back (Element (elts, minimum_offsets, padding)); + + // Add the springs for the VerticalAxisGroups in this system. + + // If the user has specified the offsets of the individual staves, fix the + // springs at the given distances. Otherwise, use stretchable springs. + SCM details = get_details (elements_.back ()); + SCM manual_dists = ly_assoc_get (ly_symbol2scm ("alignment-distances"), details, SCM_EOL); + vsize last_spaceable_staff = 0; + bool found_spaceable_staff = false; + for (vsize i = 0; i < elts.size (); ++i) + { + if (is_spaceable (elts[i])) + { + // We don't add a spring for the first staff, since + // we are only adding springs _between_ staves here. + if (!found_spaceable_staff) + { + found_spaceable_staff = true; + last_spaceable_staff = i; + continue; + } + + Spring spring (0.5, 0.0); + SCM spec = elts[last_spaceable_staff]->get_property ("staff-staff-spacing"); + alter_spring_from_spacing_spec (spec, &spring); + + springs_.push_back (spring); + Real min_distance = (found_spaceable_staff ? minimum_offsets_with_min_dist[last_spaceable_staff] : 0) - minimum_offsets_with_min_dist[i]; + springs_.back ().ensure_min_distance (min_distance); + + if (scm_is_pair (manual_dists)) + { + if (scm_is_number (scm_car (manual_dists))) + { + Real dy = scm_to_double (scm_car (manual_dists)); + + springs_.back ().set_distance (dy); + springs_.back ().set_min_distance (dy); + springs_.back ().set_inverse_stretch_strength (0); + } + manual_dists = scm_cdr (manual_dists); + } + last_spaceable_staff = i; + } + } + + // Corner case: there was only one staff, and it wasn't spaceable. + // Mark it spaceable, because we do not allow non-spaceable staves + // to be at the top or bottom of a system. + if (!found_spaceable_staff && elts.size ()) + mark_as_spaceable (elts[0]); +} + +void +Page_layout_problem::append_prob (Prob *prob, Spring const& spring, Real padding) +{ + Skyline_pair *sky = Skyline_pair::unsmob (prob->get_property ("vertical-skylines")); + Real minimum_distance = 0; + bool tight_spacing = to_boolean (prob->get_property ("tight-spacing")); + + if (sky) + { + minimum_distance = (*sky)[UP].distance (bottom_skyline_); + bottom_skyline_ = (*sky)[DOWN]; + } + else if (Stencil *sten = unsmob_stencil (prob->get_property ("stencil"))) + { + Interval iv = sten->extent (Y_AXIS); + minimum_distance = iv[UP] - bottom_skyline_.max_height (); + + bottom_skyline_.clear (); + bottom_skyline_.set_minimum_height (iv[DOWN]); + } + + Spring spring_copy = spring; + if (tight_spacing) + { + spring_copy.set_min_distance (minimum_distance); + spring_copy.set_inverse_stretch_strength (0.0); + spring_copy.set_distance (0.0); + } + else + spring_copy.ensure_min_distance (minimum_distance + padding); + + springs_.push_back (spring_copy); + elements_.push_back (Element (prob, padding)); +} + +void +Page_layout_problem::solve_rod_spring_problem (bool ragged) +{ + Simple_spacer spacer; + + for (vsize i = 0; i < springs_.size (); ++i) + spacer.add_spring (springs_[i]); + + spacer.solve (page_height_, ragged); + solution_ = spacer.spring_positions (); + + if (!spacer.fits ()) + { + Real overflow = spacer.configuration_length (spacer.force ()) + - page_height_; + if (ragged && overflow < 1e-6) + warning (_ ("cannot fit music on page: ragged-spacing was requested, but page was compressed")); + else + { + warning (_f ("cannot fit music on page: overflow is %f", + overflow)); + warning (_ ("compressing music to fit")); + vsize space_count = solution_.size (); + Real spacing_increment = overflow / (space_count - 2); + for (vsize i = 2; i < space_count; i++) + solution_[i] -= (i-1) * spacing_increment; + } + } +} + +// The solution_ vector stores the position of every live VerticalAxisGroup +// and every title. From that information, +// 1) within each system, stretch the staves so they land at the right position +// 2) find the offset of each system (relative to the printable area of the page). +// TODO: this function is getting too long, maybe split it up? +SCM +Page_layout_problem::find_system_offsets () +{ + SCM system_offsets = SCM_EOL; + SCM *tail = &system_offsets; + + // spring_idx 0 is the top of the page. Interesting values start from 1. + vsize spring_idx = 1; + vector loose_lines; + vector loose_line_min_distances; + Grob *last_spaceable_line = 0; + Real last_spaceable_line_translation = 0; + Interval last_title_extent; + for (vsize i = 0; i < elements_.size (); ++i) + { + if (elements_[i].prob) + { + *tail = scm_cons (scm_from_double (solution_[spring_idx]), SCM_EOL); + tail = SCM_CDRLOC (*tail); + Interval prob_extent = unsmob_stencil (elements_[i].prob->get_property ("stencil"))->extent (Y_AXIS); + + // Lay out any non-spaceable lines between this line and + // the last one. + if (loose_lines.size ()) + { + Interval loose_extent = loose_lines.back ()->extent (loose_lines.back (), Y_AXIS); + Real min_distance = (-loose_extent[DOWN] + prob_extent[UP] + + elements_[i].padding); + + loose_line_min_distances.push_back (min_distance); + loose_lines.push_back (0); + + distribute_loose_lines (loose_lines, loose_line_min_distances, + last_spaceable_line_translation, -solution_[spring_idx]); + loose_lines.clear (); + loose_line_min_distances.clear (); + } + + last_spaceable_line = 0; + last_spaceable_line_translation = -solution_[spring_idx]; + last_title_extent = prob_extent; + spring_idx++; + } + else + { + // Getting this signs right here is a little tricky. The configuration + // we return has zero at the top of the page and positive numbers further + // down, as does the solution_ vector. Within a staff, however, positive + // numbers are up. + // TODO: perhaps change the way the page 'configuration variable works so + // that it is consistent with the usual up/down sign conventions in + // Lilypond. Then this would be less confusing. + + // These two positions are relative to the page (with positive numbers being + // down). + Real first_staff_position = solution_[spring_idx]; + Real first_staff_min_translation = elements_[i].min_offsets.size () ? elements_[i].min_offsets[0] : 0; + Real system_position = first_staff_position + first_staff_min_translation; + + // Position the staves within this system. + vector const& min_offsets = elements_[i].min_offsets; + bool found_spaceable_staff = false; + for (vsize staff_idx = 0; staff_idx < elements_[i].staves.size (); ++staff_idx) + { + Grob *staff = elements_[i].staves[staff_idx]; + staff->set_property ("system-Y-offset", scm_from_double (-system_position)); + + if (is_spaceable (staff)) + { + // this is relative to the system: negative numbers are down. + staff->translate_axis (system_position - solution_[spring_idx], Y_AXIS); + + // Lay out any non-spaceable lines between this line and + // the last one. + if (loose_lines.size ()) + { + if (staff_idx) + loose_line_min_distances.push_back (min_offsets[staff_idx-1] - min_offsets[staff_idx]); + else + loose_line_min_distances.push_back (elements_[i].padding - min_offsets[staff_idx]); + loose_lines.push_back (staff); + + distribute_loose_lines (loose_lines, loose_line_min_distances, + last_spaceable_line_translation, -solution_[spring_idx]); + loose_lines.clear (); + loose_line_min_distances.clear (); + } + last_spaceable_line = staff; + last_spaceable_line_translation = -solution_[spring_idx]; + found_spaceable_staff = true; + spring_idx++; + } + else + { + if (loose_lines.empty ()) + loose_lines.push_back (last_spaceable_line); + + if (staff_idx) + // NOTE: the way we do distances between loose lines (and other lines too, actually) + // is not the most accurate way possible: we only insert rods between adjacent + // lines. To be more accurate, we could insert rods between non-adjacent lines + // using a scheme similar to the one in set_column_rods. + loose_line_min_distances.push_back (min_offsets[staff_idx-1] - min_offsets[staff_idx]); + else + { // this is the first line in a system + Real min_dist = 0; + if (loose_lines.back ()) + // distance to the final line in the preceding system, + // including 'system-system-spacing 'padding + min_dist = (Axis_group_interface::minimum_distance (loose_lines.back (), + staff, + Y_AXIS) + + elements_[i].padding); + else if (!last_title_extent.is_empty ()) + // distance to the preceding title, + // including 'markup-system-spacing 'padding + min_dist = (staff->extent (staff, Y_AXIS)[UP] - last_title_extent[DOWN] + + elements_[i].padding); + else // distance to the top margin + min_dist = header_padding_ + header_height_ + staff->extent (staff, Y_AXIS)[UP]; + + loose_line_min_distances.push_back (min_dist); + } + loose_lines.push_back (staff); + } + } + + // Corner case: even if a system has no live staves, it still takes up + // one spring (a system with one live staff also takes up one spring), + // which we need to increment past. + if (!found_spaceable_staff) + spring_idx++; + + *tail = scm_cons (scm_from_double (system_position), SCM_EOL); + tail = SCM_CDRLOC (*tail); + } + } + + if (loose_lines.size ()) + { + Grob *last = loose_lines.back (); + Interval last_ext = last->extent (last, Y_AXIS); + loose_line_min_distances.push_back (-last_ext[DOWN] + footer_height_ + footer_padding_); + loose_lines.push_back (0); + + distribute_loose_lines (loose_lines, loose_line_min_distances, + last_spaceable_line_translation, -page_height_); + + } + + assert (spring_idx == solution_.size () - 1); + return system_offsets; +} + +// Given two lines that are already spaced (the first and last +// elements of loose_lines), distribute some unspaced lines between +// them. +// first_translation and last_translation are relative to the page. +void +Page_layout_problem::distribute_loose_lines (vector const &loose_lines, + vector const &min_distances, + Real first_translation, Real last_translation) +{ + Simple_spacer spacer; + for (vsize i = 0; i + 1 < loose_lines.size (); ++i) + { + SCM spec = get_spacing_spec (loose_lines[i], loose_lines[i+1], false, 0, INT_MAX); + Spring spring (1.0, 0.0); + alter_spring_from_spacing_spec (spec, &spring); + spring.ensure_min_distance (min_distances[i]); + spacer.add_spring (spring); + } + + // Remember: offsets are decreasing, since we're going from UP to DOWN! + spacer.solve (first_translation - last_translation, false); + + vector solution = spacer.spring_positions (); + for (vsize i = 1; i + 1 < solution.size (); ++i) + { + Real system_offset = scm_to_double (loose_lines[i]->get_property ("system-Y-offset")); + loose_lines[i]->translate_axis (first_translation - solution[i] - system_offset, Y_AXIS); + } +} + +SCM +Page_layout_problem::solution (bool ragged) +{ + solve_rod_spring_problem (ragged); + return find_system_offsets (); +} + +// Build upper and lower skylines for a system. We don't yet know the positions +// of the staves within the system, so we make the skyline as conservative as +// possible. That is, for the upper skyline, we pretend that all of the staves +// in the system are packed together close to the top system; for the lower +// skyline, we pretend that all of the staves are packed together close to +// the bottom system. +// +// The upper skyline is relative to the top staff; the lower skyline is relative to +// the bottom staff. +void +Page_layout_problem::build_system_skyline (vector const& staves, + vector const& minimum_translations, + Skyline *up, + Skyline *down) +{ + if (minimum_translations.empty ()) + return; + + assert (staves.size () == minimum_translations.size ()); + Real first_translation = minimum_translations[0]; + Real last_spaceable_dy = 0; + Real first_spaceable_dy = 0; + bool found_spaceable_staff = false; + + for (vsize i = 0; i < staves.size (); ++i) + { + Real dy = minimum_translations[i] - first_translation; + Grob *g = staves[i]; + Skyline_pair *sky = Skyline_pair::unsmob (g->get_property ("vertical-skylines")); + if (sky) + { + up->raise (-dy); + up->merge ((*sky)[UP]); + up->raise (dy); + + down->raise (-dy); + down->merge ((*sky)[DOWN]); + down->raise (dy); + } + if (is_spaceable (staves[i])) + { + if (!found_spaceable_staff) + { + found_spaceable_staff = true; + first_spaceable_dy = dy; + } + last_spaceable_dy = dy; + } + } + + // Leave the up skyline at a position relative + // to the top spaceable staff. + up->raise (-first_spaceable_dy); + + // Leave the down skyline at a position + // relative to the bottom spaceable staff. + down->raise (-last_spaceable_dy); +} + +Interval +Page_layout_problem::prob_extent (Prob *p) +{ + Stencil *sten = unsmob_stencil (p->get_property ("stencil")); + return sten ? sten->extent (Y_AXIS) : Interval (0, 0); +} + +Interval +Page_layout_problem::first_staff_extent (Element const& e) +{ + if (e.prob) + return prob_extent (e.prob); + else if (e.staves.size ()) + return e.staves[0]->extent (e.staves[0], Y_AXIS); + + return Interval (0, 0); +} + +Interval +Page_layout_problem::last_staff_extent (Element const& e) +{ + if (e.prob) + return prob_extent (e.prob); + else if (e.staves.size ()) + return e.staves.back ()->extent (e.staves.back (), Y_AXIS); + + return Interval (0, 0); +} + +SCM +Page_layout_problem::get_details (Element const& elt) +{ + if (elt.staves.empty ()) + return SCM_EOL; + + return get_details (elt.staves.back ()->get_system ()); +} + +SCM +Page_layout_problem::get_details (Grob *g) +{ + Grob *left_bound = dynamic_cast (g)->get_bound (LEFT); + return left_bound->get_property ("line-break-system-details"); +} + +bool +Page_layout_problem::is_spaceable (Grob *g) +{ + return !scm_is_number (g->get_property ("staff-affinity")); +} + +void +Page_layout_problem::mark_as_spaceable (Grob *g) +{ + g->set_property ("staff-affinity", SCM_BOOL_F); +} + +bool +Page_layout_problem::read_spacing_spec (SCM spec, Real* dest, SCM sym) +{ + SCM pair = scm_sloppy_assq (sym, spec); + if (scm_is_pair (pair) && scm_is_number (scm_cdr (pair))) + { + *dest = scm_to_double (scm_cdr (pair)); + return true; + } + return false; +} + +// If there is a forced, fixed spacing between BEFORE and AFTER, return it. +// Otherwise, return -infinity_f. +// If after is spaceable, it is the (spaceable_index + 1)th spaceable grob in +// its alignment. +Real +Page_layout_problem::get_fixed_spacing (Grob *before, Grob *after, int spaceable_index, bool pure, int start, int end) +{ + Spanner *after_sp = dynamic_cast (after); + SCM cache_symbol = (is_spaceable (before) && is_spaceable (after)) + ? ly_symbol2scm ("spaceable-fixed-spacing") + : ly_symbol2scm ("loose-fixed-spacing"); + if (pure) + { + // The result of this function doesn't depend on "end," so we can reduce the + // size of the cache by ignoring it. + SCM cached = after_sp->get_cached_pure_property (cache_symbol, start, 0); + if (scm_is_number (cached)) + return robust_scm2double (cached, 0.0); + } + + SCM spec = Page_layout_problem::get_spacing_spec (before, after, pure, start, end); + Real ret = -infinity_f; + Real stretchability = 0; + if (Page_layout_problem::read_spacing_spec (spec, &stretchability, ly_symbol2scm ("stretchability")) + && stretchability == 0) + Page_layout_problem::read_spacing_spec (spec, &ret, ly_symbol2scm ("basic-distance")); + + // If we're pure, then paper-columns have not had their systems set, + // and so elts[i]->get_system () is unreliable. + System *sys = pure ? Grob::get_system (before) : before->get_system (); + Grob *left_bound = sys ? sys->get_maybe_pure_bound (LEFT, pure, start, end) : 0; + + if (is_spaceable (before) && is_spaceable (after) && left_bound) + { + SCM details = left_bound->get_property ("line-break-system-details"); + SCM manual_dists = ly_assoc_get (ly_symbol2scm ("alignment-distances"), details, SCM_EOL); + if (scm_is_pair (manual_dists)) + { + SCM forced = robust_list_ref (spaceable_index - 1, manual_dists); + if (scm_is_number (forced)) + ret = max (ret, scm_to_double (forced)); + } + } + + // Cache the result. As above, we ignore "end." + if (pure) + after_sp->cache_pure_property (cache_symbol, start, 0, scm_from_double (ret)); + + return ret; +} + +static SCM +add_stretchability (SCM alist, Real stretch) +{ + if (!scm_is_pair (scm_sloppy_assq (ly_symbol2scm ("stretchability"), alist))) + return scm_acons (ly_symbol2scm ("stretchability"), scm_from_double (stretch), alist); + + return alist; +} + +// We want to put a large stretch between a non-spaceable line and its +// non-affinity staff. We want to put an even larger stretch between +// a non-spaceable line and the top/bottom of the page. That way, +// a spacing-affinity UP line at the bottom of the page will still be +// placed close to its staff. +const double LARGE_STRETCH = 10e5; +const double HUGE_STRETCH = 10e7; + +// Returns the spacing spec connecting BEFORE to AFTER. +SCM +Page_layout_problem::get_spacing_spec (Grob *before, Grob *after, bool pure, int start, int end) +{ + // If there are no spacing wishes, return a very flexible spring. + // This will occur, for example, if there are lyrics at the bottom of + // the page, in which case we don't want the spring from the lyrics to + // the bottom of the page to have much effect. + if (!before || !after) + return add_stretchability (SCM_EOL, HUGE_STRETCH); + + if (is_spaceable (before)) + { + if (is_spaceable (after)) + return before->get_maybe_pure_property ("staff-staff-spacing", pure, start, end); + else + { + Direction affinity = to_dir (after->get_maybe_pure_property ("staff-affinity", pure, start, end)); + return (affinity == DOWN) + ? add_stretchability (after->get_maybe_pure_property ("nonstaff-unrelatedstaff-spacing", pure, start, end), + LARGE_STRETCH) + : after->get_maybe_pure_property ("nonstaff-relatedstaff-spacing", pure, start, end); + } + } + else + { + if (is_spaceable (after)) + { + Direction affinity = to_dir (before->get_maybe_pure_property ("staff-affinity", pure, start, end)); + return (affinity == UP) + ? add_stretchability (before->get_maybe_pure_property ("nonstaff-unrelatedstaff-spacing", pure, start, end), + LARGE_STRETCH) + : before->get_maybe_pure_property ("nonstaff-relatedstaff-spacing", pure, start, end); + } + else + { + Direction before_affinity = to_dir (before->get_maybe_pure_property ("staff-affinity", pure, start, end)); + Direction after_affinity = to_dir (after->get_maybe_pure_property ("staff-affinity", pure, start, end)); + static bool warned = false; + if (after_affinity > before_affinity + && !warned && !pure) + { + warning (_ ("staff-affinities should only decrease")); + warned = true; + } + if (before_affinity != UP) + return before->get_maybe_pure_property ("nonstaff-nonstaff-spacing", pure, start, end); + else if (after_affinity != DOWN) + return before->get_maybe_pure_property ("nonstaff-nonstaff-spacing", pure, start, end); + return add_stretchability (before->get_maybe_pure_property ("nonstaff-unrelatedstaff-spacing", pure, start, end), + LARGE_STRETCH); + } + } + + assert (0); + return SCM_BOOL_F; +} + +void +Page_layout_problem::alter_spring_from_spacing_spec (SCM spec, Spring* spring) +{ + Real space; + Real stretch; + Real min_dist; + if (read_spacing_spec (spec, &space, ly_symbol2scm ("basic-distance"))) + spring->set_distance (space); + if (read_spacing_spec (spec, &min_dist, ly_symbol2scm ("minimum-distance"))) + spring->set_min_distance (min_dist); + spring->set_default_strength (); + + if (read_spacing_spec (spec, &stretch, ly_symbol2scm ("stretchability"))) + { + spring->set_inverse_stretch_strength (stretch); + spring->set_inverse_compress_strength (stretch); + } +} + +vector +Page_layout_problem::filter_dead_elements (vector const& input) +{ + vector output; + for (vsize i = 0; i < input.size (); ++i) + { + if (Hara_kiri_group_spanner::has_interface (input[i])) + Hara_kiri_group_spanner::consider_suicide (input[i]); + + if (input[i]->is_live ()) + output.push_back (input[i]); + } + + return output; +}