/*
- 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--2007 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 is a title, we add back in the page-top-space. */
- Real height = first_line_.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_;
if (extra_systems)
{
ret.systems_per_page_.back () += extra_systems;
- ret.demerits_ += 200000;
+ ret.force_.back () = BAD_SPACING_PENALTY;
}
if (extra_pages)
{
- ret.force_.insert (ret.force_.end (), extra_pages, 200000);
+ ret.force_.insert (ret.force_.end (), extra_pages, BAD_SPACING_PENALTY);
ret.systems_per_page_.insert (ret.systems_per_page_.end (), extra_pages, 0);
- ret.demerits_ += 200000;
}
-
- ret.demerits_ += ret.penalty_;
return ret;
}
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)
{
bool last = line == lines_.size () - 1;
Page_spacing space (breaker_->page_height (page + first_page_num_, last),
- breaker_->page_top_space ());
+ breaker_);
Page_spacing_node &cur = 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--;)
{
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;
}
}
projects / lilypond.git / blobdiff