X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fpage-spacing.cc;h=76ef484b14daf04c23f9e424b203ed186f935c2a;hb=9c08d5a772049794eac7210558670e43f9e349ff;hp=82a037bde57c1c2f2d791c6ebe96053b2f238002;hpb=45493eefc3647f4b8c83515ee3176e05a6250195;p=lilypond.git diff --git a/lily/page-spacing.cc b/lily/page-spacing.cc index 82a037bde5..76ef484b14 100644 --- a/lily/page-spacing.cc +++ b/lily/page-spacing.cc @@ -1,10 +1,20 @@ /* - page-spacing.cc - implement routines for spacing - systems vertically on pages + This file is part of LilyPond, the GNU music typesetter. - source file of the GNU LilyPond music typesetter + Copyright (C) 2006--2010 Joe Neeman - (c) 2006--2007 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-spacing.hh" @@ -16,10 +26,14 @@ void Page_spacing::calc_force () { - if (rod_height_ + last_line_.bottom_padding_ >= page_height_) - force_ = infinity_f; + Real height = page_height_ + - breaker_->min_whitespace_at_top_of_page (first_line_) + - breaker_->min_whitespace_at_bottom_of_page (last_line_); + + if (rod_height_ + last_line_.bottom_padding_ >= height) + force_ = -infinity_f; else - force_ = (page_height_ - rod_height_ - last_line_.bottom_padding_ - spring_len_) + force_ = (height - rod_height_ - last_line_.bottom_padding_ - spring_len_) / max (0.1, inverse_spring_k_); } @@ -33,10 +47,24 @@ Page_spacing::resize (Real new_height) void Page_spacing::append_system (const Line_details &line) { - rod_height_ += last_line_.padding_; + if (rod_height_) + { + rod_height_ += line.tallness_; + } + else + { + rod_height_ += line.full_height (); + first_line_ = line; + } - rod_height_ += line.extent_.length (); - spring_len_ += line.space_; + // line.space_ measures the spring which goes from the bottom refpoint + // of one system to the top refpoint of the next. spring_len_ measures + // how much of that is stretchable. + Real refpoint_dist = last_line_.tallness_ + + last_line_.refpoint_extent_[DOWN] + - line.refpoint_extent_[UP]; + Real space = line.title_ ? last_line_.title_space_ : last_line_.space_; + spring_len_ += max (0.0, space - refpoint_dist); inverse_spring_k_ += line.inverse_hooke_; last_line_ = line; @@ -47,15 +75,22 @@ Page_spacing::append_system (const Line_details &line) void Page_spacing::prepend_system (const Line_details &line) { - if (rod_height_) - rod_height_ += line.padding_; - else + if (!rod_height_) last_line_ = line; - rod_height_ += line.extent_.length (); - spring_len_ += line.space_; + rod_height_ -= first_line_.full_height (); + rod_height_ += first_line_.tallness_; + rod_height_ += line.full_height(); + + Real refpoint_dist = line.tallness_ + + line.refpoint_extent_[DOWN] + - first_line_.refpoint_extent_[UP]; + Real space = first_line_.title_ ? line.title_space_ : line.space_; + spring_len_ += max (0.0, space - refpoint_dist); inverse_spring_k_ += line.inverse_hooke_; + first_line_ = line; + calc_force (); } @@ -77,6 +112,38 @@ Page_spacer::Page_spacer (vector const &lines, vsize first_page_nu ragged_last_ = breaker->is_last () && breaker->ragged_last (); } +Page_spacing_result +Page_spacer::solve () +{ + if (simple_state_.empty ()) + { + simple_state_.resize (lines_.size ()); + for (vsize i = 0; i < lines_.size (); ++i) + calc_subproblem (VPOS, i); + } + + Page_spacing_result ret; + ret.penalty_ = simple_state_.back ().penalty_ + + lines_.back ().page_penalty_ + lines_.back ().turn_penalty_; + ret.system_count_status_ = simple_state_.back ().system_count_status_; + + vsize system = lines_.size () - 1; + while (system != VPOS) + { + Page_spacing_node const& cur = simple_state_[system]; + vsize system_count = (cur.prev_ == VPOS) ? system + 1 : system - cur.prev_; + + ret.force_.push_back (cur.force_); + ret.systems_per_page_.push_back (system_count); + ret.demerits_ += cur.force_ * cur.force_; + system = cur.prev_; + } + + reverse (ret.force_); + reverse (ret.systems_per_page_); + return ret; +} + Page_spacing_result Page_spacer::solve (vsize page_count) { @@ -84,11 +151,10 @@ Page_spacer::solve (vsize page_count) resize (page_count); Page_spacing_result ret; - ret.force_.resize (page_count); - ret.systems_per_page_.resize (page_count); vsize system = lines_.size () - 1; - vsize tack_onto_the_end = 0; + vsize extra_systems = 0; + vsize extra_pages = 0; if (isinf (state_.at (system, page_count-1).demerits_)) { @@ -104,13 +170,29 @@ Page_spacer::solve (vsize page_count) if (i) { - tack_onto_the_end = system - i; + extra_systems = system - i; system = i; } else - return Page_spacing_result (); /* couldn't salvage it -- probably going to crash */ + { + /* try chopping off pages from the end */ + vsize j; + for (j = page_count; j && isinf (state_.at (system, j-1).demerits_); j--) + ; + + if (j) + { + extra_pages = page_count - j; + page_count = j; + } + else + return Page_spacing_result (); /* couldn't salvage it -- probably going to crash */ + } } + ret.force_.resize (page_count); + ret.systems_per_page_.resize (page_count); + ret.system_count_status_ = state_.at (system, page_count-1).system_count_status_; ret.penalty_ = state_.at (system, page_count-1).penalty_ + lines_.back ().page_penalty_ + lines_.back ().turn_penalty_; @@ -125,10 +207,21 @@ Page_spacer::solve (vsize page_count) if (p == 0) ret.systems_per_page_[p] = system + 1; else - ret.systems_per_page_[p] = system - ps.prev_ + tack_onto_the_end; + ret.systems_per_page_[p] = system - ps.prev_; system = ps.prev_; } - ret.demerits_ += ret.penalty_; + + if (extra_systems) + { + ret.systems_per_page_.back () += extra_systems; + ret.force_.back () = BAD_SPACING_PENALTY; + } + if (extra_pages) + { + ret.force_.insert (ret.force_.end (), extra_pages, BAD_SPACING_PENALTY); + ret.systems_per_page_.insert (ret.systems_per_page_.end (), extra_pages, 0); + } + return ret; } @@ -149,44 +242,113 @@ Page_spacer::resize (vsize page_count) max_page_count_ = page_count; } +// Carries out one step in the dynamic programming algorithm for putting systems +// on a fixed number of pages. One call to this routine calculates the best +// configuration for putting lines 0 through LINE-1 on PAGE+1 pages, provided that +// we have previously called calc_subproblem(page-1, k) for every k < LINE. +// +// This algorithm is similar to the constrained-breaking algorithm. +// +// If page == VPOS, we act on simple_state_ instead of state_. This is useful if +// we don't want to constrain the number of pages that the solution has. In this +// case, the algorithm looks more like the page-turn-page-breaking algorithm. But +// the subproblems look similar for both, so we reuse this method. bool Page_spacer::calc_subproblem (vsize page, vsize line) { bool last = line == lines_.size () - 1; - Page_spacing space (breaker_->page_height (page + first_page_num_, last)); - Page_spacing_node &cur = state_.at (line, page); + + // Note: if page == VPOS then we don't actually know yet which page number we're + // working on, so we have to recalculate the page height in the loop. Therefore + // our early-exit condition from the loop depends on paper_height rather than + // page_height (ie. we break only if we would overfill a page without margins + // or headers/footers). Otherwise, the algorithm would not be optimal: + // if our page has a very large header then perhaps + // we should look ahead a few systems in order to find the best solution. A + // good example of this is input/regression/page-spacing-tall-headfoot.ly + vsize page_num = page == VPOS ? 0 : page; + Real paper_height = breaker_->paper_height (); + Page_spacing space (breaker_->page_height (page_num + first_page_num_, last), + breaker_); + Page_spacing_node &cur = page == VPOS ? simple_state_[line] : state_.at (line, page); bool ragged = ragged_ || (ragged_last_ && last); + int line_count = 0; - for (vsize page_start = line+1; page_start > page && page_start--;) + for (vsize page_start = line+1; page_start > page_num && page_start--;) { - Page_spacing_node const *prev = page > 0 ? &state_.at (page_start-1, page-1) : 0; + Page_spacing_node const *prev = 0; + + if (page == VPOS) + { + if (page_start > 0) + { + prev = &simple_state_[page_start-1]; + space.resize (breaker_->page_height (prev->page_ + 1, last)); + } + else + space.resize (breaker_->page_height (first_page_num_, last)); + } + else if (page > 0) + prev = &state_.at (page_start-1, page-1); space.prepend_system (lines_[page_start]); - if (page_start < line && (isinf (space.force_) || (space.force_ < 0 && ragged))) + + bool overfull = (space.rod_height_ > paper_height + || (ragged + && (space.rod_height_ + space.spring_len_ > paper_height))); + // This 'if' statement is a little hard to parse. It won't consider this configuration + // if it is overfull unless the current configuration is the first one with this start + // point. We also make an exception (and consider this configuration) if the previous + // configuration we tried had fewer lines than min-systems-per-page. + if (!breaker_->too_few_lines (line_count) + && page_start < line + && overfull) break; + line_count += lines_[page_start].compressed_nontitle_lines_count_; if (page > 0 || page_start == 0) { - if (line == lines_.size () - 1 && ragged_last_ && space.force_ > 0) + // If the last page is ragged, set its force to zero. This way, we will leave + // the last page half-empty rather than trying to balance things out + // (which only makes sense in non-ragged situations). + if (line == lines_.size () - 1 && ragged && last && space.force_ > 0) space.force_ = 0; - /* we may have to deal with single lines that are taller than a page */ - if (isinf (space.force_) && page_start == line) - space.force_ = -200000; + Real demerits = space.force_ * space.force_; + + // Clamp the demerits at BAD_SPACING_PENALTY, even if the page + // is overfull. This ensures that TERRIBLE_SPACING_PENALTY takes + // precedence over overfull pages. + demerits = min (demerits, BAD_SPACING_PENALTY); + demerits += (prev ? prev->demerits_ : 0); - Real dem = fabs (space.force_) + (prev ? prev->demerits_ : 0); - Real penalty = 0; + Real penalty = breaker_->line_count_penalty (line_count); if (page_start > 0) - penalty = lines_[page_start-1].page_penalty_ + penalty += lines_[page_start-1].page_penalty_ + (page % 2 == 0) ? lines_[page_start-1].turn_penalty_ : 0; - dem += penalty; - if (dem < cur.demerits_ || page_start == line) + /* Deal with widow/orphan lines */ + /* Last line of paragraph is first line on the new page */ + if ((page_start > 0) && + (page_start < lines_.size ()) && + (lines_[page_start].last_markup_line_)) + penalty += breaker_->orphan_penalty (); + /* First line of paragraph is last line on the previous page */ + if ((page_start > 0) && + (page_start < lines_.size ()) && + (lines_[page_start-1].first_markup_line_)) + penalty += breaker_->orphan_penalty (); + + demerits += penalty; + if (demerits < cur.demerits_ || page_start == line) { - cur.demerits_ = dem; + cur.demerits_ = demerits; cur.force_ = space.force_; cur.penalty_ = penalty + (prev ? prev->penalty_ : 0); + cur.system_count_status_ = breaker_->line_count_status (line_count) + | (prev ? prev->system_count_status_ : 0); cur.prev_ = page_start - 1; + cur.page_ = prev ? prev->page_ + 1 : first_page_num_; } }