/*
- 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 <joeneeman@gmail.com>
- (c) 2006--2009 Joe Neeman <joeneeman@gmail.com>
+ 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 <http://www.gnu.org/licenses/>.
*/
#include "page-spacing.hh"
void
Page_spacing::calc_force ()
{
- /* If the first system contains a title, we add back in the page-top-space. */
- bool starts_with_title = first_line_.compressed_nontitle_lines_count_ < first_line_.compressed_lines_count_;
- Real height = starts_with_title ? page_height_ + page_top_space_ : page_height_;
+ 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;
void
Page_spacing::append_system (const Line_details &line)
{
- if (!rod_height_)
- first_line_ = 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_;
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_;
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;
+ 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)
{
// 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),
- breaker_->page_top_space ());
- 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. In that case,
+ // the algorithm may not be optimal: if our page has a very large header then perhaps
+ // we need to look ahead a few systems in order to find the best solution. But
+ // we won't, because we stop once we overfill the page with the large header.
+ vsize page_num = page == VPOS ? 0 : page;
+ 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]);
penalty += lines_[page_start-1].page_penalty_
+ (page % 2 == 0) ? lines_[page_start-1].turn_penalty_ : 0;
+ /* 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.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_;
}
}
projects / lilypond.git / blobdiff