X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fpage-spacing.cc;h=33cf18a3fe8a64f52821229f96a3bd73e407ab1c;hb=4a6773dd60ef6ef481e37b00049c9eedcb5b8193;hp=945a52b60aeef2a8890007b6ebae9a115249ee01;hpb=34858b0d7a48573ba2249aa3922b172db8e02acb;p=lilypond.git diff --git a/lily/page-spacing.cc b/lily/page-spacing.cc index 945a52b60a..33cf18a3fe 100644 --- a/lily/page-spacing.cc +++ b/lily/page-spacing.cc @@ -1,58 +1,62 @@ /* - 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 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" #include "matrix.hh" +#include "page-breaking.hh" #include "warn.hh" -/* - A much simplified rods-and-springs problem. - */ -struct Page_spacing -{ - Real force_; - Real page_height_; - Real rod_height_; - Real spring_len_; - Real inverse_spring_k_; - - Line_details last_line_; - - Page_spacing (Real page_height) - { - page_height_ = page_height; - clear (); - } - - void calc_force (); - - void append_system (const Line_details &line); - void prepend_system (const Line_details &line); - void clear (); -}; - void Page_spacing::calc_force () { - if (rod_height_ + last_line_.bottom_padding_ >= page_height_ || !inverse_spring_k_) + 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_) / inverse_spring_k_; + force_ = (height - rod_height_ - last_line_.bottom_padding_ - spring_len_) + / max (0.1, inverse_spring_k_); +} + +void +Page_spacing::resize (Real new_height) +{ + page_height_ = new_height; + calc_force (); } 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_; inverse_spring_k_ += line.inverse_hooke_; @@ -64,15 +68,17 @@ 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 (); + rod_height_ -= first_line_.full_height (); + rod_height_ += first_line_.tallness_; + rod_height_ += line.full_height(); spring_len_ += line.space_; inverse_spring_k_ += line.inverse_hooke_; + first_line_ = line; + calc_force (); } @@ -83,178 +89,65 @@ Page_spacing::clear () inverse_spring_k_ = 0; } -/* for each forbidden page break, merge the systems around it into one system. */ -static vector -compress_lines (const vector &orig) -{ - vector ret; - - for (vsize i = 0; i < orig.size (); i++) - { - if (ret.size () && ret.back ().page_permission_ == SCM_EOL) - { - Line_details const &old = ret.back (); - Line_details compressed = orig[i]; - compressed.extent_[DOWN] = old.extent_[DOWN]; - compressed.extent_[UP] = old.extent_[UP] + orig[i].extent_.length () + old.padding_; - compressed.space_ += old.space_; - compressed.inverse_hooke_ += old.inverse_hooke_; - - /* we don't need the force_ field for the vertical spacing, - so we use force_ = n to signal that the line was compressed, - reducing the number of lines by n (and force_ = 0 otherwise). - This makes uncompression much easier. */ - compressed.force_ = old.force_ + 1; - ret.back () = compressed; - } - else - { - ret.push_back (orig[i]); - ret.back ().force_ = 0; - } - } - return ret; -} - -/* translate the number of systems-per-page into something meaningful for - the uncompressed lines. -*/ -static vector -uncompress_solution (vector const &systems_per_page, - vector const &compressed) -{ - vector ret; - vsize start_sys = 0; - - for (vsize i = 0; i < systems_per_page.size (); i++) - { - int compressed_count = 0; - for (vsize j = start_sys; j < start_sys + systems_per_page[i]; j++) - compressed_count += (int)compressed[j].force_; - - ret.push_back (systems_per_page[i] + compressed_count); - start_sys += systems_per_page[i]; - } - return ret; -} - -/* the cases for page_count = 1 or 2 can be done in O(n) time. Since they - are by far the most common cases, we have special functions for them */ -static Spacing_result -space_systems_on_1_page (vector const &lines, Real page_height, bool ragged) -{ - Page_spacing space (page_height); - Spacing_result ret; - - for (vsize i = 0; i < lines.size (); i++) - space.append_system (lines[i]); - - ret.systems_per_page_.push_back (lines.size ()); - ret.force_.push_back (ragged ? min (space.force_, 0.0) : space.force_); - ret.penalty_ = lines.back ().page_penalty_ + lines.back ().turn_penalty_; - ret.demerits_ = ret.force_.back () * ret.force_.back () + ret.penalty_; - - return ret; -} - -static Spacing_result -space_systems_on_2_pages (vector const &lines, - Real page_height, - bool ragged, - bool ragged_last) -{ - /* if there is a forced break, this reduces to 2 1-page problems */ - for (vsize i = 0; i < lines.size () - 1; i++) - if (lines[i].page_permission_ == ly_symbol2scm ("force")) - { - vector lines1 (lines.begin (), lines.begin () + i + 1); - vector lines2 (lines.begin () + i + 1, lines.end ()); - Spacing_result p1 = space_systems_on_1_page (lines1, page_height, ragged); - Spacing_result p2 = space_systems_on_1_page (lines2, page_height, ragged || ragged_last); - - p1.systems_per_page_.push_back (p2.systems_per_page_[0]); - p1.force_.push_back (p2.force_[0]); - p1.penalty_ += p2.penalty_ - lines[i].turn_penalty_; - p1.demerits_ += p2.demerits_ - lines[i].turn_penalty_; - return p1; - } - - vector page1_force; - vector page2_force; - Page_spacing page1 (page_height); - Page_spacing page2 (page_height); - - page1_force.resize (lines.size () - 1, infinity_f); - page2_force.resize (lines.size () - 1, infinity_f); - - for (vsize i = 0; i < page1_force.size (); i++) - { - page1.append_system (lines[i]); - page2.prepend_system (lines[lines.size () - 1 - i]); - page1_force[i] = (ragged && page1.force_ < 0 && i > 0) ? infinity_f : page1.force_; - - if (ragged || ragged_last) - page2_force[page2_force.size () - 1 - i] = - (page2.force_ < 0 && i < page1_force.size () - 1) ? infinity_f : 0; - else - page2_force[page2_force.size () - 1 - i] = page2.force_; - } - vsize best_sys_count = 1; - Real best_demerits = infinity_f; - for (vsize i = 0; i < page1_force.size (); i++) - { - Real dem = page1_force[i] * page1_force[i] - + page2_force[i] * page2_force[i] - + lines[i+1].page_penalty_ - + lines.back ().page_penalty_ + lines.back ().turn_penalty_; - if (dem < best_demerits) - { - best_demerits = dem; - best_sys_count = i+1; - } - } - - Spacing_result ret; - ret.systems_per_page_.push_back (best_sys_count); - ret.systems_per_page_.push_back (lines.size () - best_sys_count); - ret.force_.push_back (page1_force[best_sys_count-1]); - ret.force_.push_back (page2_force[best_sys_count-1]); - ret.penalty_ = lines[best_sys_count-1].page_penalty_ - + lines.back ().page_penalty_ - + lines.back ().turn_penalty_; - ret.demerits_ = best_demerits; - - return ret; -} - -Page_spacer::Page_spacer (vector const &lines, Real page_height, bool ragged, bool ragged_last) +Page_spacer::Page_spacer (vector const &lines, vsize first_page_num, Page_breaking const *breaker) : lines_ (lines) { - page_height_ = page_height; + first_page_num_ = first_page_num; + breaker_ = breaker; max_page_count_ = 0; - ragged_ = ragged; - ragged_last_ = ragged_last; + ragged_ = breaker->ragged (); + ragged_last_ = breaker->is_last () && breaker->ragged_last (); } -Spacing_result +Page_spacing_result Page_spacer::solve (vsize page_count) { if (page_count > max_page_count_) resize (page_count); - Spacing_result ret; - ret.force_.resize (page_count); - ret.systems_per_page_.resize (page_count); + Page_spacing_result ret; vsize system = lines_.size () - 1; + vsize extra_systems = 0; + vsize extra_pages = 0; if (isinf (state_.at (system, page_count-1).demerits_)) { programming_error ("tried to space systems on a bad number of pages"); - return Spacing_result (); /* bad number of pages */ + /* Usually, this means that we tried to cram too many systems into + to few pages. To avoid crashing, we look for the largest number of + systems that we can fit properly onto the right number of pages. + All the systems that don't fit get tacked onto the last page. + */ + vsize i; + for (i = system; isinf (state_.at (i, page_count-1).demerits_) && i; i--) + ; + + if (i) + { + extra_systems = system - i; + system = i; + } + else + { + /* 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.penalty_ = state_.at (system, page_count-1).penalty_ + lines_.back ().page_penalty_ + lines_.back ().turn_penalty_; @@ -272,7 +165,18 @@ Page_spacer::solve (vsize page_count) 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; } @@ -293,42 +197,78 @@ 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. bool Page_spacer::calc_subproblem (vsize page, vsize line) { - Page_spacing space (page_height_); + bool last = line == lines_.size () - 1; + Page_spacing space (breaker_->page_height (page + first_page_num_, last), + breaker_); Page_spacing_node &cur = state_.at (line, page); - bool ragged = ragged_ || (ragged_last_ && line == lines_.size () - 1); + bool ragged = ragged_ || (ragged_last_ && last); + int line_count = 0; for (vsize page_start = line+1; page_start > page && page_start--;) { Page_spacing_node const *prev = page > 0 ? &state_.at (page_start-1, page-1) : 0; space.prepend_system (lines_[page_start]); - if (page_start < line && (isinf (space.force_) || (space.force_ < 0 && ragged))) + + // 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 + && (isinf (space.force_) || (space.force_ < 0 && ragged))) 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 */ + Real demerits = space.force_ * space.force_; + /* If a single line is taller than a page, we need to consider it as + a possible solution (but we give it a very bad score). */ if (isinf (space.force_) && page_start == line) - space.force_ = -200000; + 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; } } @@ -340,102 +280,3 @@ Page_spacer::calc_subproblem (vsize page, vsize line) return !isinf (cur.demerits_); } -vsize -min_page_count (vector const &uncompressed_lines, - Real page_height, bool ragged, bool ragged_last) -{ - vsize ret = 1; - Real cur_rod_height = 0; - vector lines = compress_lines (uncompressed_lines); - - assert (lines.size ()); - for (vsize i = lines.size (); i--;) - { - bool rag = ragged || (ragged_last && ret == 1); - Real ext_len = lines[i].extent_.length (); - Real next_height = cur_rod_height + ext_len - + (rag ? lines[i].space_ : 0) - + ((cur_rod_height > 0) ? lines[i].padding_: 0); - - if ((next_height > page_height && cur_rod_height > 0) - || (i < lines.size () - 1 && lines[i].page_permission_ == ly_symbol2scm ("force"))) - { - ret++; - cur_rod_height = ext_len + (rag ? lines[i].space_ : 0); - } - else - cur_rod_height = next_height; - } - - return ret; -} - -Spacing_result -space_systems_on_n_pages (vector const &lines, - vsize n, - Real page_height, - bool ragged, - bool ragged_last) -{ - vector compressed_lines = compress_lines (lines); - Spacing_result ret; - assert (n >= min_page_count (lines, page_height, ragged, ragged_last)); - - if (n > compressed_lines.size ()) - return Spacing_result (); - if (n == 1) - ret = space_systems_on_1_page (compressed_lines, page_height, ragged || ragged_last); - else if (n == 2) - ret = space_systems_on_2_pages (compressed_lines, page_height, ragged, ragged_last); - - Page_spacer ps (compressed_lines, page_height, ragged, ragged_last); - ret = ps.solve (n); - - ret.systems_per_page_ = uncompress_solution (ret.systems_per_page_, compressed_lines); - return ret; -} - -Spacing_result -space_systems_on_n_or_one_more_pages (vector const &lines, - vsize n, - Real page_height, - Real odd_pages_penalty, - bool ragged, - bool ragged_last) -{ - Spacing_result n_res = space_systems_on_n_pages (lines, n, page_height, ragged, ragged_last); - Spacing_result m_res = space_systems_on_n_pages (lines, n+1, page_height, ragged, ragged_last); - n_res.demerits_ += odd_pages_penalty; - n_res.force_.back () += odd_pages_penalty; - - if (n_res.demerits_ < m_res.demerits_) - return n_res; - return m_res; -} - -Spacing_result -space_systems_on_best_pages (vector const &lines, - Real page_height, - Real odd_pages_penalty, - bool ragged, - bool ragged_last) -{ - vector compressed_lines = compress_lines (lines); - vsize min_p_count = min_page_count (compressed_lines, page_height, ragged, ragged_last); - - Page_spacer ps (compressed_lines, page_height, ragged, ragged_last); - Spacing_result best = ps.solve (min_p_count); - best.force_.back () += (min_p_count % 2) ? odd_pages_penalty : 0; - best.demerits_ += (min_p_count % 2) ? odd_pages_penalty : 0; - - for (vsize i = min_p_count+1; i <= compressed_lines.size (); i++) - { - Spacing_result cur = ps.solve (i); - cur.demerits_ += (i % 2) ? odd_pages_penalty : 0; - if (cur.demerits_ < best.demerits_) - best = cur; - } - - best.systems_per_page_ = uncompress_solution (best.systems_per_page_, compressed_lines); - return best; -}