/*
- page-breaking.cc -- implement a superclass and utility
- functions shared by various page-breaking algorithms
+ 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/>.
+*/
+
+/*
+ This is a utility class for page-breaking algorithms. There are some complex
+ parts of this class, some of which are useful to understand if you intend
+ to write a page breaking algorithm (ie. a subclass of Page_breaking). Most
+ of these complexities were introduced in order to break the problem of
+ page-breaking into simpler subproblems and to hide some of the bookkeeping
+ complexities of page breaking from the page breaking algorithms.
+
+ COMPRESSED LINES
+ There are several functions that actually distribute systems across pages
+ (for example, the space_systems_XXX and pack_systems_XXX functions). If
+ each of these functions had to handle \noPageBreak, it would be a mess.
+ Therefore, we handle \noPageBreak by "compressing" the list of systems
+ before doing any layout: we concatenate any two systems separated by a
+ \noPageBreak into a single system. The page-breaking functions can do their
+ magic without encountering a \noPageBreak; we then "uncompress" the systems
+ at the end. We almost always work with cached_line_details_, which are
+ "compressed."
+
+ CHUNKS
+ The basic operation of a page breaking algorithm is to repeatedly request
+ some systems from the line-breaker and place those systems on some pages.
+ With each repetition, the page breaking algorithm asks the line-breaker for
+ some systems that it thinks will help it achieve a better layout. The
+ Page_breaking class provides functionality to facilitate this in the case
+ that the page breaking algorithm only cares about the number of systems.
+
+ Even if a page breaking algorithm only cares number of systems, there may
+ be many ways to satisfy its request. For example, in a piece with 2 scores
+ and a request for 10 systems, we could return 5 systems from each score or
+ 4 from the first and 6 from the second. Even within a score, we might
+ want to try several different line breaking configurations with a fixed
+ system count; if there is a forced \pageBreak, for example, we might wish
+ to tweak the number of systems on both sides of the \pageBreak independently.
+
+ The Page_breaking class takes care of finding these configurations. It
+ divides the piece into "chunks" and sets up the line-breaker in such a way
+ that the number of systems in each chunk can be modified independently.
+ Chunks never cross score boundaries; each title and markup is its own chunk.
+ When a page breaking algorithm requests a number of systems, the Page_breaker
+ stores an array of potential configurations, which the page breaking
+ algorithm can iterate over using current_configuration(vsize).
+
+ LINE_DIVISION
+ A Line_division is simply a way of storing the exact way in which the
+ total number of systems is distributed among chunks. Note that a
+ Line_division may not (in fact, usually will not) describe all of the chunks
+ in the entire book. Rather, it will describe the subset of chunks that lie
+ between some fixed starting and ending point. This subset of chunks changes
+ whenever a page breaking algorithm asks to consider a different pair of
+ starting and ending breakpoints. In particular, a Line_division should be
+ discarded after a call to set_current_breakpoints, since that Line_division
+ refers to a subset of chunks which might be different from the current
+ subset of chunks under consideration.
*/
#include "page-breaking.hh"
#include "international.hh"
#include "item.hh"
#include "output-def.hh"
+#include "page-layout-problem.hh"
#include "page-spacing.hh"
#include "paper-book.hh"
#include "paper-score.hh"
#include "system.hh"
#include "warn.hh"
+/* for each forbidden page break, merge the systems around it into one
+ system. */
+static vector<Line_details>
+compress_lines (const vector<Line_details> &orig)
+{
+ vector<Line_details> ret;
+
+ for (vsize i = 0; i < orig.size (); i++)
+ {
+ if (ret.size () && !scm_is_symbol (ret.back ().page_permission_))
+ {
+ Line_details const &old = ret.back ();
+ Line_details compressed = orig[i];
+ /*
+ We must account for the padding between the lines that we are compressing.
+ The padding values come from "old," which is the upper system here. Note
+ the meaning of tight-spacing: if a system has tight-spacing, then the padding
+ _before_ it is ignored.
+ */
+ Real padding = 0;
+ if (!orig[i].tight_spacing_)
+ padding = orig[i].title_ ? old.title_padding_ : old.padding_;
+
+ // FIXME: double check these. Doesn't foo.piggyback (bar) mean
+ // that foo goes on top?
+ // TODO: break out a Line_details::piggyback from here?
+ compressed.shape_ = old.shape_.piggyback (orig[i].shape_, padding);
+ compressed.refpoint_extent_[UP] = old.refpoint_extent_[UP];
+ compressed.refpoint_extent_[DOWN] += compressed.shape_.rest_[UP] - old.shape_.rest_[UP];
+ compressed.space_ += old.space_;
+ compressed.inverse_hooke_ += old.inverse_hooke_;
+
+ compressed.compressed_lines_count_ = old.compressed_lines_count_ + 1;
+ compressed.compressed_nontitle_lines_count_ =
+ old.compressed_nontitle_lines_count_ + (compressed.title_ ? 0 : 1);
+
+ // compressed.title_ is true if and only if the first of its
+ // compressed lines was a title.
+ compressed.title_ = old.title_;
+ 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<vsize>
+uncompress_solution (vector<vsize> const &systems_per_page,
+ vector<Line_details> const &compressed)
+{
+ vector<vsize> 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 += compressed[j].compressed_lines_count_ - 1;
+
+ ret.push_back (systems_per_page[i] + compressed_count);
+ start_sys += systems_per_page[i];
+ }
+ return ret;
+}
+
/* for Page_breaking, the start index (when we are dealing with the stuff
between a pair of breakpoints) refers to the break_ index of the end of
the previous page. So the system index of the start of the current page
vsize
Page_breaking::next_system (Break_position const &break_pos) const
{
- vsize sys = break_pos.sys_;
+ vsize sys = break_pos.system_spec_index_;
if (sys == VPOS) /* beginning of the book */
return 0;
- if (all_[sys].pscore_ && !break_pos.score_ender_)
+ if (system_specs_[sys].pscore_ && !break_pos.score_ender_)
return sys; /* the score overflows the previous page */
- return sys + 1; /* this page starts with a new sys */
+ return sys + 1; /* this page starts with a new System_spec */
}
-Page_breaking::Page_breaking (Paper_book *pb, Break_predicate is_break)
+Page_breaking::Page_breaking (Paper_book *pb, Break_predicate is_break, Prob_break_predicate prob_break)
{
book_ = pb;
+ system_count_ = 0;
+ paper_height_ = robust_scm2double (pb->paper_->c_variable ("paper-height"), 1.0);
+ ragged_ = to_boolean (pb->paper_->c_variable ("ragged-bottom"));
+ ragged_last_ = to_boolean (pb->paper_->c_variable ("ragged-last-bottom"));
+ systems_per_page_ = max (0, robust_scm2int (pb->paper_->c_variable ("systems-per-page"), 0));
+ max_systems_per_page_ = max (0, robust_scm2int (pb->paper_->c_variable ("max-systems-per-page"), 0));
+ min_systems_per_page_ = max (0, robust_scm2int (pb->paper_->c_variable ("min-systems-per-page"), 0));
+ orphan_penalty_ = robust_scm2int (pb->paper_->c_variable ("orphan-penalty"), 100000);
+
+ if (systems_per_page_ && (max_systems_per_page_ || min_systems_per_page_))
+ {
+ warning (_f ("ignoring min-systems-per-page and max-systems-per-page because systems-per-page was set"));
+ min_systems_per_page_ = max_systems_per_page_ = 0;
+ }
+ if (max_systems_per_page_ && min_systems_per_page_ > max_systems_per_page_)
+ {
+ warning (_f ("min-systems-per-page is larger than max-systems-per-page, ignoring both values"));
+ min_systems_per_page_ = max_systems_per_page_ = 0;
+ }
+
create_system_list ();
- find_chunks_and_breaks (is_break);
+ find_chunks_and_breaks (is_break, prob_break);
}
Page_breaking::~Page_breaking ()
{
}
+bool
+Page_breaking::ragged () const
+{
+ return ragged_;
+}
+
+bool
+Page_breaking::ragged_last () const
+{
+ return ragged_last_;
+}
+
+int
+Page_breaking::systems_per_page () const
+{
+ return systems_per_page_;
+}
+
+int
+Page_breaking::max_systems_per_page () const
+{
+ return max_systems_per_page_;
+}
+
+int
+Page_breaking::min_systems_per_page () const
+{
+ return min_systems_per_page_;
+}
+
+vsize
+Page_breaking::system_count () const
+{
+ return system_count_;
+}
+
+bool
+Page_breaking::too_many_lines (int line_count) const
+{
+ return max_systems_per_page () > 0 && line_count > max_systems_per_page ();
+}
+
+bool
+Page_breaking::too_few_lines (int line_count) const
+{
+ return line_count < min_systems_per_page ();
+}
+
+Real
+Page_breaking::line_count_penalty (int line_count) const
+{
+ if (too_many_lines (line_count))
+ return (line_count - max_systems_per_page ()) * TERRIBLE_SPACING_PENALTY;
+ if (too_few_lines (line_count))
+ return (min_systems_per_page () - line_count) * TERRIBLE_SPACING_PENALTY;
+
+ return 0;
+}
+
+int
+Page_breaking::line_count_status (int line_count) const
+{
+ if (too_many_lines (line_count))
+ return SYSTEM_COUNT_TOO_MANY;
+ if (too_few_lines (line_count))
+ return SYSTEM_COUNT_TOO_FEW;
+
+ return SYSTEM_COUNT_OK;
+}
+
/* translate indices into breaks_ into start-end parameters for the line breaker */
void
Page_breaking::line_breaker_args (vsize sys,
vsize *line_breaker_start,
vsize *line_breaker_end)
{
- assert (all_[sys].pscore_);
- assert (next_system (start) <= sys && sys <= end.sys_);
+ assert (system_specs_[sys].pscore_);
+ assert (next_system (start) <= sys && sys <= end.system_spec_index_);
- if (start.sys_ == sys)
+ if (start.system_spec_index_ == sys)
*line_breaker_start = start.score_break_;
else
*line_breaker_start = 0;
- if (end.sys_ == sys)
+ if (end.system_spec_index_ == sys)
*line_breaker_end = end.score_break_;
else
*line_breaker_end = VPOS;
}
void
-Page_breaking::break_into_pieces (vsize start_break, vsize end_break, Line_division const &div)
+Page_breaking::break_into_pieces (vsize start_break, vsize end_break,
+ Line_division const &div)
{
vector<Break_position> chunks = chunk_list (start_break, end_break);
- assert (chunks.size () == div.size () + 1);
+ bool ignore_div = false;
+ if (chunks.size () != div.size () + 1)
+ {
+ programming_error ("did not find a valid page breaking configuration");
+ ignore_div = true;
+ }
for (vsize i = 0; i + 1 < chunks.size (); i++)
{
vsize sys = next_system (chunks[i]);
- if (all_[sys].pscore_)
+ if (system_specs_[sys].pscore_)
{
vsize start;
vsize end;
line_breaker_args (sys, chunks[i], chunks[i+1], &start, &end);
- vector<Column_x_positions> pos = line_breaking_[sys].solve (start, end, div[i]);
- all_[sys].pscore_->root_system ()->break_into_pieces (pos);
+ vector<Column_x_positions> pos = ignore_div
+ ? line_breaking_[sys].best_solution (start, end)
+ : line_breaking_[sys].solve (start, end, div[i]);
+ system_specs_[sys].pscore_->root_system ()->break_into_pieces (pos);
}
}
}
Page_breaking::systems ()
{
SCM ret = SCM_EOL;
- for (vsize sys = 0; sys < all_.size (); sys++)
+ for (vsize sys = 0; sys < system_specs_.size (); sys++)
{
- if (all_[sys].pscore_)
+ if (system_specs_[sys].pscore_)
{
- all_[sys].pscore_->root_system ()->do_break_substitution_and_fixup_refpoints ();
- SCM lines = all_[sys].pscore_->root_system ()->get_broken_system_grobs ();
+ system_specs_[sys].pscore_->root_system ()
+ ->do_break_substitution_and_fixup_refpoints ();
+ SCM lines = system_specs_[sys].pscore_->root_system ()
+ ->get_broken_system_grobs ();
ret = scm_cons (lines, ret);
}
- else
+ else if (Prob *pb = system_specs_[sys].prob_)
{
- Prob *pb = all_[sys].prob_;
ret = scm_cons (scm_list_1 (pb->self_scm ()), ret);
pb->unprotect ();
}
return scm_append (scm_reverse (ret));
}
-vector<Line_details>
-Page_breaking::line_details (vsize start_break, vsize end_break, Line_division const &div)
+SCM
+Page_breaking::make_page (int page_num, bool last) const
{
- vector<Break_position> chunks = chunk_list (start_break, end_break);
- vector<Line_details> ret;
- assert (chunks.size () == div.size () + 1);
+ bool last_part = ly_scm2bool (book_->paper_->c_variable ("is-last-bookpart"));
+ SCM mod = scm_c_resolve_module ("scm page");
+ SCM make_page_scm = scm_c_module_lookup (mod, "make-page");
- for (vsize i = 0; i + 1 < chunks.size (); i++)
- {
- vsize sys = next_system (chunks[i]);
- if (all_[sys].pscore_)
- {
- vsize start;
- vsize end;
- line_breaker_args (sys, chunks[i], chunks[i+1], &start, &end);
+ make_page_scm = scm_variable_ref (make_page_scm);
- vector<Line_details> details = line_breaking_[sys].line_details (start, end, div[i]);
- ret.insert (ret.end (), details.begin (), details.end ());
- }
- else
- {
- assert (div[i] == 1);
- ret.push_back (Line_details (all_[sys].prob_));
- }
- }
- return ret;
+ return scm_apply_0 (make_page_scm,
+ scm_list_n (book_->self_scm (),
+ ly_symbol2scm ("page-number"), scm_from_int (page_num),
+ ly_symbol2scm ("is-last-bookpart"), scm_from_bool (last_part),
+ ly_symbol2scm ("is-bookpart-last-page"), scm_from_bool (last),
+ SCM_UNDEFINED));
}
+// Returns the total height of the paper, including margins and
+// space for the header/footer. This is an upper bound on
+// page_height, and it doesn't depend on the current page.
Real
-Page_breaking::page_height (int page_num, bool last)
+Page_breaking::paper_height () const
{
- SCM mod = scm_c_resolve_module ("scm page");
- SCM calc_height = scm_c_module_lookup (mod, "calc-printable-height");
- SCM make_page = scm_c_module_lookup (mod, "make-page");
+ return paper_height_;
+}
- calc_height = scm_variable_ref (calc_height);
- make_page = scm_variable_ref (make_page);
+Real
+Page_breaking::page_height (int page_num, bool last) const
+{
+ // The caches allow us to store the page heights for any
+ // non-negative page numbers. We use a negative value in the
+ // cache to signal that that position has not yet been initialized.
+ // This means that we won't cache properly if page_num is negative or
+ // if calc_height returns a negative number. But that's likely to
+ // be rare, so it shouldn't affect performance.
+ vector<Real>& cache = last ? last_page_height_cache_ : page_height_cache_;
+ if (page_num >= 0 && (int) cache.size () > page_num && cache[page_num] >= 0)
+ return cache[page_num];
+ else
+ {
+ SCM mod = scm_c_resolve_module ("scm page");
+ SCM page = make_page (page_num, last);
+ SCM calc_height = scm_c_module_lookup (mod, "calc-printable-height");
+ calc_height = scm_variable_ref (calc_height);
+
+ SCM height_scm = scm_apply_1 (calc_height, page, SCM_EOL);
+ Real height = scm_to_double (height_scm);
- SCM page = scm_apply_0 (make_page, scm_list_n (
- book_->self_scm (),
- ly_symbol2scm ("page-number"), scm_from_int (page_num),
- ly_symbol2scm ("is-last"), scm_from_bool (last),
- SCM_UNDEFINED));
- SCM height = scm_apply_1 (calc_height, page, SCM_EOL);
- return scm_to_double (height) - scm_to_double (book_->paper_->c_variable ("page-top-space"));
+ if (page_num >= 0)
+ {
+ if ((int) cache.size () <= page_num)
+ cache.resize (page_num + 1, -1);
+ cache[page_num] = height;
+ }
+ return height;
+ }
}
SCM
{
Break_position const &pos = breaks_[breakpoint];
- if (pos.sys_ == VPOS)
+ if (pos.system_spec_index_ == VPOS)
return SCM_EOL;
- if (all_[pos.sys_].pscore_)
+ if (system_specs_[pos.system_spec_index_].pscore_)
return pos.col_->get_property (str);
- return all_[pos.sys_].prob_->get_property (str);
+ return system_specs_[pos.system_spec_index_].prob_->get_property (str);
}
SCM
-Page_breaking::make_pages (vector<vsize> lines_per_page, SCM systems)
+Page_breaking::get_page_configuration (SCM systems, int page_num, bool ragged, bool last)
{
- SCM layout_module = scm_c_resolve_module ("scm layout-page-layout");
- SCM page_module = scm_c_resolve_module ("scm page");
+ SCM dummy_page = make_page (page_num, last);
+ Page_layout_problem layout (book_, dummy_page, systems);
+ return scm_is_pair (systems) ? layout.solution (ragged) : SCM_EOL;
+}
- SCM make_page = scm_c_module_lookup (layout_module, "stretch-and-draw-page");
+SCM
+Page_breaking::draw_page (SCM systems, SCM configuration, int page_num, bool last)
+{
+ // Create a stencil for each system.
+ SCM paper_systems = SCM_EOL;
+ for (SCM s = scm_reverse (systems); scm_is_pair (s); s = scm_cdr (s))
+ {
+ SCM paper_system = scm_car (s);
+ if (Grob *g = unsmob_grob (scm_car (s)))
+ {
+ System *sys = dynamic_cast<System*> (g);
+ paper_system = sys->get_paper_system ();
+ }
+
+ paper_systems = scm_cons (paper_system, paper_systems);
+ }
+
+ // Create the page and draw it.
+ SCM page = make_page (page_num, last);
+ SCM page_module = scm_c_resolve_module ("scm page");
SCM page_stencil = scm_c_module_lookup (page_module, "page-stencil");
- make_page = scm_variable_ref (make_page);
page_stencil = scm_variable_ref (page_stencil);
- SCM book = book_->self_scm ();
- bool ragged_all = to_boolean (book_->paper_->c_variable ("ragged-bottom"));
- bool ragged_last = to_boolean (book_->paper_->c_variable ("ragged-last-bottom"));
- int first_page_number = robust_scm2int (book_->paper_->c_variable ("first-page-number"), 1);
+ Prob *p = unsmob_prob (page);
+ p->set_property ("lines", paper_systems);
+ p->set_property ("configuration", configuration);
+ scm_apply_1 (page_stencil, page, SCM_EOL);
+
+ return page;
+}
+
+SCM
+Page_breaking::make_pages (vector<vsize> lines_per_page, SCM systems)
+{
+ if (scm_is_null (systems))
+ return SCM_EOL;
+
+ int first_page_number
+ = robust_scm2int (book_->paper_->c_variable ("first-page-number"), 1);
SCM ret = SCM_EOL;
+ SCM label_page_table = book_->top_paper ()->c_variable ("label-page-table");
+ if (label_page_table == SCM_UNDEFINED)
+ label_page_table = SCM_EOL;
+
+ // Build a list of (systems . configuration) pairs. Note that we lay out
+ // the staves and find the configurations before drawing anything. Some
+ // grobs (like tuplet brackets) look at their neighbours while drawing
+ // themselves. If this happens before the neighbouring staves have
+ // been laid out, bad side-effects could happen (in particular,
+ // Align_interface::align_to_ideal_distances might be called).
+ SCM systems_and_configs = SCM_EOL;
for (vsize i = 0; i < lines_per_page.size (); i++)
{
- SCM page_num = scm_from_int (i + first_page_number);
- SCM last = scm_from_bool (i == lines_per_page.size () - 1);
- SCM ragged = scm_from_bool (ragged_all || (to_boolean (last) && ragged_last));
+ int page_num = i + first_page_number;
+ bool bookpart_last_page = (i == lines_per_page.size () - 1);
+ bool rag = ragged () || (bookpart_last_page && ragged_last ());
SCM line_count = scm_from_int (lines_per_page[i]);
SCM lines = scm_list_head (systems, line_count);
- SCM page = scm_apply_0 (make_page,
- scm_list_n (book, lines, page_num, ragged, last, SCM_UNDEFINED));
+ SCM config = get_page_configuration (lines, page_num, rag, bookpart_last_page);
- scm_apply_1 (page_stencil, page, SCM_EOL);
- ret = scm_cons (page, ret);
+ systems_and_configs = scm_cons (scm_cons (lines, config), systems_and_configs);
systems = scm_list_tail (systems, line_count);
}
- ret = scm_reverse (ret);
+
+ // Now it's safe to make the pages.
+ int page_num = first_page_number + lines_per_page.size () - 1;
+ for (SCM s = systems_and_configs; scm_is_pair (s); s = scm_cdr (s))
+ {
+ SCM lines = scm_caar (s);
+ SCM config = scm_cdar (s);
+ bool bookpart_last_page = (s == systems_and_configs);
+ SCM page = draw_page (lines, config, page_num, bookpart_last_page);
+
+ /* collect labels */
+ SCM page_num_scm = scm_from_int (page_num);
+ for (SCM l = lines ; scm_is_pair (l) ; l = scm_cdr (l))
+ {
+ SCM labels = SCM_EOL;
+ if (Grob * line = unsmob_grob (scm_car (l)))
+ {
+ System *system = dynamic_cast<System*> (line);
+ labels = system->get_property ("labels");
+ }
+ else if (Prob *prob = unsmob_prob (scm_car (l)))
+ labels = prob->get_property ("labels");
+
+ for (SCM lbls = labels ; scm_is_pair (lbls) ; lbls = scm_cdr (lbls))
+ label_page_table = scm_cons (scm_cons (scm_car (lbls), page_num_scm),
+ label_page_table);
+ }
+
+ ret = scm_cons (page, ret);
+ --page_num;
+ }
+ book_->top_paper ()->set_variable (ly_symbol2scm ("label-page-table"), label_page_table);
return ret;
}
{
if (Paper_score *ps = dynamic_cast<Paper_score*> (unsmob_music_output (scm_car (s))))
{
- SCM system_count = ps->layout ()->c_variable ("system-count");
-
- if (scm_is_number (system_count))
- s = scm_append (scm_list_3 (scm_list_1 (scm_car (s)),
- scm_vector_to_list (ps->get_paper_systems ()),
- scm_cdr (s)));
- else
- all_.push_back (System_spec (ps));
+ system_specs_.push_back (System_spec (ps));
}
else
{
assert (pb);
pb->protect ();
- all_.push_back (System_spec (pb));
+ system_specs_.push_back (System_spec (pb));
}
}
+ if (!system_specs_.size ())
+ system_specs_.push_back (System_spec ());
}
void
-Page_breaking::find_chunks_and_breaks (Break_predicate is_break)
+Page_breaking::find_chunks_and_breaks (Break_predicate is_break, Prob_break_predicate prob_is_break)
{
SCM force_sym = ly_symbol2scm ("force");
chunks_.push_back (Break_position ());
breaks_.push_back (Break_position ());
- for (vsize i = 0; i < all_.size (); i++)
+ for (vsize i = 0; i < system_specs_.size (); i++)
{
- if (all_[i].pscore_)
+ if (system_specs_[i].pscore_)
{
- vector<Grob*> cols = all_[i].pscore_->root_system ()->used_columns ();
+ vector<Grob*> cols = system_specs_[i].pscore_->root_system ()->used_columns ();
+ vector<Grob*> forced_line_break_cols;
+
+ SCM system_count = system_specs_[i].pscore_->layout ()->c_variable ("system-count");
+ if (scm_is_number (system_count))
+ {
+ // With system-count given, the line configuration for
+ // this score is fixed. We need to ensure that chunk
+ // boundaries only occur at line breaks.
+ Constrained_breaking breaking (system_specs_[i].pscore_);
+ vector<Line_details> details = breaking.line_details (0, VPOS, scm_to_int (system_count));
+
+ for (vsize j = 0; j < details.size (); j++)
+ forced_line_break_cols.push_back (details[j].last_column_);
+ }
+
+ int last_forced_line_break_idx = 0;
+ vsize forced_line_break_idx = 0;
vector<vsize> line_breaker_columns;
line_breaker_columns.push_back (0);
for (vsize j = 1; j < cols.size (); j++)
{
- bool last = j == cols.size () - 1;
- bool break_point = is_break (cols[j]);
+ if (forced_line_break_cols.size ())
+ {
+ if (forced_line_break_idx >= forced_line_break_cols.size ()
+ || forced_line_break_cols[forced_line_break_idx] != cols[j])
+ continue;
+ else
+ forced_line_break_idx++;
+ }
+
+ bool last = (j == cols.size () - 1);
+ bool break_point = is_break && is_break (cols[j]);
bool chunk_end = cols[j]->get_property ("page-break-permission") == force_sym;
Break_position cur_pos = Break_position (i,
line_breaker_columns.size (),
cols[j],
last);
- if (break_point || (i == all_.size () - 1 && last))
+ // NOTE: even in the breaks_ list, forced_line_count_
+ // refers to the number of lines between a
+ // Break_position and the start of that /chunk/. This
+ // is needed for system_count_bounds to work correctly,
+ // since it mixes Break_positions from breaks_ and
+ // chunks_.
+ if (scm_is_number (system_count))
+ cur_pos.forced_line_count_ = forced_line_break_idx - last_forced_line_break_idx;
+
+ if (break_point || (i == system_specs_.size () - 1 && last))
breaks_.push_back (cur_pos);
if (chunk_end || last)
- chunks_.push_back (cur_pos);
+ {
+ chunks_.push_back (cur_pos);
+ last_forced_line_break_idx = forced_line_break_idx;
+ }
if ((break_point || chunk_end) && !last)
line_breaker_columns.push_back (j);
}
- line_breaking_.push_back (Constrained_breaking (all_[i].pscore_, line_breaker_columns));
+ line_breaking_.push_back (Constrained_breaking (system_specs_[i].pscore_, line_breaker_columns));
}
- else
+ else if (system_specs_[i].prob_)
{
- /* TODO: we want some way of applying Break_p to a prob? */
- if (i == all_.size () - 1)
+ bool break_point = prob_is_break && prob_is_break (system_specs_[i].prob_);
+ if (break_point || i == system_specs_.size () - 1)
breaks_.push_back (Break_position (i));
chunks_.push_back (Break_position (i));
+
+ /* FIXME: shouldn't we push a Null_breaker or similar dummy
+ class? --hwn */
line_breaking_.push_back (Constrained_breaking (NULL));
}
}
Break_position start = breaks_[start_index];
Break_position end = breaks_[end_index];
- vsize i;
- for (i = 0; i < chunks_.size () && chunks_[i] <= start; i++)
+ vsize i = 0;
+ for (; i < chunks_.size () && chunks_[i] <= start; i++)
;
vector<Break_position> ret;
}
Page_breaking::Line_division
-Page_breaking::system_count_bounds (vector<Break_position> const &chunks, bool min)
+Page_breaking::system_count_bounds (vector<Break_position> const &chunks,
+ bool min)
{
assert (chunks.size () >= 2);
for (vsize i = 0; i + 1 < chunks.size (); i++)
{
vsize sys = next_system (chunks[i]);
- if (all_[sys].pscore_)
+
+ if (chunks[i+1].forced_line_count_)
+ ret[i] = chunks[i+1].forced_line_count_;
+ else if (system_specs_[sys].pscore_)
{
vsize start;
vsize end;
return ret;
}
-vector<Page_breaking::Line_division>
-Page_breaking::line_divisions (vsize start,
- vsize end,
- vsize system_count,
- Line_division lower_bound,
- Line_division upper_bound)
+void
+Page_breaking::set_current_breakpoints (vsize start,
+ vsize end,
+ vsize system_count,
+ Line_division lower_bound,
+ Line_division upper_bound)
{
- vector<Break_position> chunks = chunk_list (start, end);
+ system_count_ = system_count;
+ current_chunks_ = chunk_list (start, end);
+ current_start_breakpoint_ = start;
+ current_end_breakpoint_ = end;
+ clear_line_details_cache ();
if (!lower_bound.size ())
- lower_bound = system_count_bounds (chunks, true);
+ lower_bound = system_count_bounds (current_chunks_, true);
if (!upper_bound.size ())
- upper_bound = system_count_bounds (chunks, false);
+ upper_bound = system_count_bounds (current_chunks_, false);
- assert (lower_bound.size () == chunks.size () - 1);
- assert (upper_bound.size () == chunks.size () - 1);
+ assert (lower_bound.size () == current_chunks_.size () - 1);
+ assert (upper_bound.size () == current_chunks_.size () - 1);
- vector<Line_division> ret;
Line_division work_in_progress;
-
+ current_configurations_.clear ();
line_divisions_rec (system_count,
lower_bound,
upper_bound,
- &ret,
&work_in_progress);
- return ret;
+
+ /* we only consider a constant number of configurations. Otherwise,
+ this becomes slow when there are many small scores. The constant
+ 5 is somewhat arbitrary. */
+ if (current_configurations_.size () > 5)
+ {
+ vector<pair<Real,vsize> > dems_and_indices;
+
+ for (vsize i = 0; i < current_configurations_.size (); i++)
+ {
+ cache_line_details (i);
+ Real dem = 0;
+ for (vsize j = 0; j < cached_line_details_.size (); j++)
+ dem += cached_line_details_[j].force_ * cached_line_details_[j].force_
+ + cached_line_details_[j].break_penalty_;
+
+ dems_and_indices.push_back (pair<Real,vsize> (dem, i));
+ }
+ vector_sort (dems_and_indices, less<pair<Real,vsize> > ());
+
+ vector<Line_division> best_5_configurations;
+ for (vsize i = 0; i < 5; i++)
+ best_5_configurations.push_back (current_configurations_[dems_and_indices[i].second]);
+
+ clear_line_details_cache ();
+ current_configurations_ = best_5_configurations;
+ }
+}
+
+void
+Page_breaking::set_to_ideal_line_configuration (vsize start, vsize end)
+{
+ current_chunks_ = chunk_list (start, end);
+ current_start_breakpoint_ = start;
+ current_end_breakpoint_ = end;
+ clear_line_details_cache ();
+ system_count_ = 0;
+
+ Line_division div;
+ for (vsize i = 0; i+1 < current_chunks_.size (); i++)
+ {
+ vsize sys = next_system (current_chunks_[i]);
+
+ if (current_chunks_[i+1].forced_line_count_)
+ div.push_back (current_chunks_[i+1].forced_line_count_);
+ else if (system_specs_[sys].pscore_)
+ {
+ line_breaker_args (sys, current_chunks_[i], current_chunks_[i+1], &start, &end);
+ div.push_back (line_breaking_[sys].best_solution (start, end).size ());
+ }
+ else
+ div.push_back (1);
+
+ system_count_ += div.back ();
+ }
+ current_configurations_.clear ();
+ current_configurations_.push_back (div);
+}
+
+vsize
+Page_breaking::current_configuration_count () const
+{
+ return current_configurations_.size ();
+}
+
+void
+Page_breaking::cache_line_details (vsize configuration_index)
+{
+ if (cached_configuration_index_ != configuration_index)
+ {
+ cached_configuration_index_ = configuration_index;
+
+ Line_division &div = current_configurations_[configuration_index];
+ uncompressed_line_details_.clear ();
+ for (vsize i = 0; i + 1 < current_chunks_.size (); i++)
+ {
+ vsize sys = next_system (current_chunks_[i]);
+ if (system_specs_[sys].pscore_)
+ {
+ vsize start;
+ vsize end;
+ line_breaker_args (sys, current_chunks_[i], current_chunks_[i+1], &start, &end);
+
+ vector<Line_details> details = line_breaking_[sys].line_details (start, end, div[i]);
+ uncompressed_line_details_.insert (uncompressed_line_details_.end (), details.begin (), details.end ());
+ }
+ else
+ {
+ assert (div[i] == 1);
+ uncompressed_line_details_.push_back (system_specs_[sys].prob_
+ ? Line_details (system_specs_[sys].prob_, book_->paper_)
+ : Line_details ());
+ }
+ }
+ cached_line_details_ = compress_lines (uncompressed_line_details_);
+ compute_line_heights ();
+ }
+}
+
+void
+Page_breaking::clear_line_details_cache ()
+{
+ cached_configuration_index_ = VPOS;
+ cached_line_details_.clear ();
+ uncompressed_line_details_.clear ();
}
void
Page_breaking::line_divisions_rec (vsize system_count,
Line_division const &min_sys,
Line_division const &max_sys,
- vector<Line_division > *result,
Line_division *cur_division)
{
vsize my_index = cur_division->size ();
- vsize others_min = 0;
- vsize others_max = 0;
+ int others_min = 0;
+ int others_max = 0;
for (vsize i = my_index + 1; i < min_sys.size (); i++)
{
others_min += min_sys[i];
others_max += max_sys[i];
}
- others_max = min (others_max, system_count);
- vsize real_min = max (min_sys[my_index], system_count - others_max);
- vsize real_max = min (max_sys[my_index], system_count - others_min);
+ others_max = min (others_max, (int) system_count);
+ int real_min = max ((int) min_sys[my_index], (int) system_count - others_max);
+ int real_max = min ((int) max_sys[my_index], (int) system_count - others_min);
if (real_min > real_max || real_min <= 0)
{
return;
}
- for (vsize i = real_min; i <= real_max; i++)
+ for (int i = real_min; i <= real_max; i++)
{
cur_division->push_back (i);
if (my_index == min_sys.size () - 1)
- result->push_back (*cur_division);
+ current_configurations_.push_back (*cur_division);
else
- line_divisions_rec (system_count - i, min_sys, max_sys, result, cur_division);
+ line_divisions_rec (system_count - i, min_sys, max_sys, cur_division);
cur_division->pop_back ();
}
}
+
+void
+Page_breaking::compute_line_heights ()
+{
+ Real prev_hanging = 0;
+ Real prev_hanging_begin = 0;
+ Real prev_hanging_rest = 0;
+
+ // refpoint_hanging is the y coordinate of the origin of this system.
+ // It may not be the same as refpoint_extent[UP], which is the
+ // refpoint of the first spaceable staff in this system.
+ Real prev_refpoint_hanging = 0;
+ for (vsize i = 0; i < cached_line_details_.size (); i++)
+ {
+ Line_details& cur = cached_line_details_[i];
+ Line_shape shape = cur.shape_;
+ Real a = shape.begin_[UP];
+ Real b = shape.rest_[UP];
+ bool title = cur.title_;
+ Real refpoint_hanging = max (prev_hanging_begin + a, prev_hanging_rest + b);
+
+ if (i > 0)
+ {
+ Real padding = 0;
+ Line_details const& prev = cached_line_details_[i-1];
+ if (!cur.tight_spacing_)
+ padding = title
+ ? prev.title_padding_
+ : prev.padding_;
+ Real min_dist = title
+ ? prev.title_min_distance_
+ : prev.min_distance_;
+ refpoint_hanging = max (refpoint_hanging + padding,
+ prev_refpoint_hanging - prev.refpoint_extent_[DOWN]
+ + cur.refpoint_extent_[UP] + min_dist);
+ }
+
+ Real hanging_begin = refpoint_hanging - shape.begin_[DOWN];
+ Real hanging_rest = refpoint_hanging - shape.rest_[DOWN];
+ Real hanging = max (hanging_begin, hanging_rest);
+ cur.tallness_ = hanging - prev_hanging;
+ prev_hanging = hanging;
+ prev_hanging_begin = hanging_begin;
+ prev_hanging_rest = hanging_rest;
+ prev_refpoint_hanging = refpoint_hanging;
+ }
+}
+
+vsize
+Page_breaking::min_page_count (vsize configuration, vsize first_page_num)
+{
+ vsize ret = 1;
+ vsize page_starter = 0;
+ Real cur_rod_height = 0;
+ Real cur_spring_height = 0;
+ Real cur_page_height = page_height (first_page_num, false);
+ int line_count = 0;
+
+ cache_line_details (configuration);
+
+ if (cached_line_details_.size ())
+ cur_page_height -= min_whitespace_at_top_of_page (cached_line_details_[0]);
+
+ for (vsize i = 0; i < cached_line_details_.size (); i++)
+ {
+ Real ext_len;
+ if (cur_rod_height > 0)
+ ext_len = cached_line_details_[i].tallness_;
+ else
+ ext_len = cached_line_details_[i].full_height();
+
+ Real next_rod_height = cur_rod_height + ext_len;
+ Real next_spring_height = cur_spring_height + cached_line_details_[i].space_;
+ Real next_height = next_rod_height + (ragged () ? next_spring_height : 0)
+ + min_whitespace_at_bottom_of_page (cached_line_details_[i]);
+ int next_line_count = line_count + cached_line_details_[i].compressed_nontitle_lines_count_;
+
+ if ((!too_few_lines (line_count) && (next_height > cur_page_height && cur_rod_height > 0))
+ || too_many_lines (next_line_count)
+ || (i > 0
+ && cached_line_details_[i-1].page_permission_ == ly_symbol2scm ("force")))
+ {
+ line_count = cached_line_details_[i].compressed_nontitle_lines_count_;
+ cur_rod_height = cached_line_details_[i].full_height();
+ cur_spring_height = cached_line_details_[i].space_;
+ page_starter = i;
+
+ cur_page_height = page_height (first_page_num + ret, false);
+ cur_page_height -= min_whitespace_at_top_of_page (cached_line_details_[i]);
+
+ ret++;
+ }
+ else
+ {
+ cur_rod_height = next_rod_height;
+ cur_spring_height = next_spring_height;
+ line_count = next_line_count;
+ }
+ }
+
+ /* there are two potential problems with the last page (because we didn't know
+ it was the last page until after we managed to fit all the systems to it):
+ - we are ragged-last but the last page has a compressed spring
+ - the value returned by page_height (num, true) is smaller than the
+ value returned by page_height (num, false) and it causes the page not to
+ fit.
+
+ In either case, we just need to add one more page. This is because the last
+ line will always fit on the extra page and by adding one more page to the
+ end, the previous page is no longer the last page, so our previous
+ calculations that treated it as a non-last page were ok.
+ */
+
+ if (is_last ())
+ {
+ cur_page_height = page_height (first_page_num + ret - 1, true);
+ cur_page_height -= min_whitespace_at_top_of_page (cached_line_details_[page_starter]);
+ cur_page_height -= min_whitespace_at_bottom_of_page (cached_line_details_.back ());
+
+ Real cur_height = cur_rod_height + ((ragged_last () || ragged ()) ? cur_spring_height : 0);
+ if (!too_few_lines (line_count - cached_line_details_.back ().compressed_nontitle_lines_count_)
+ && cur_height > cur_page_height
+ /* don't increase the page count if the last page had only one system */
+ && cur_rod_height > cached_line_details_.back ().full_height ())
+ ret++;
+ assert (ret <= cached_line_details_.size ());
+ }
+
+ return ret;
+}
+
+// If systems_per_page_ is positive, we don't really try to space on N pages;
+// we just put the requested number of systems on each page and penalize
+// if the result doesn't have N pages.
+Page_spacing_result
+Page_breaking::space_systems_on_n_pages (vsize configuration, vsize n, vsize first_page_num)
+{
+ Page_spacing_result ret;
+
+ if (systems_per_page_ > 0)
+ {
+ Page_spacing_result ret = space_systems_with_fixed_number_per_page (configuration, first_page_num);
+ ret.demerits_ += (ret.force_.size () == n) ? 0 : BAD_SPACING_PENALTY;
+ return ret;
+ }
+
+ cache_line_details (configuration);
+ bool valid_n = (n >= min_page_count (configuration, first_page_num)
+ && n <= cached_line_details_.size ());
+
+ if (!valid_n)
+ programming_error ("number of pages is out of bounds");
+
+ if (n == 1 && valid_n)
+ ret = space_systems_on_1_page (cached_line_details_,
+ page_height (first_page_num, is_last ()),
+ ragged () || (is_last () && ragged_last ()));
+ else if (n == 2 && valid_n)
+ ret = space_systems_on_2_pages (configuration, first_page_num);
+ else
+ {
+ Page_spacer ps (cached_line_details_, first_page_num, this);
+ ret = ps.solve (n);
+ }
+
+ return finalize_spacing_result (configuration, ret);
+}
+
+Real
+Page_breaking::blank_page_penalty () const
+{
+ SCM penalty_sym;
+
+ if (is_last ())
+ penalty_sym = ly_symbol2scm ("blank-last-page-force");
+ else if (ends_score ())
+ penalty_sym = ly_symbol2scm ("blank-after-score-page-force");
+ else
+ penalty_sym = ly_symbol2scm ("blank-page-force");
+
+ Break_position const &pos = breaks_[current_end_breakpoint_];
+ if (Paper_score *ps = system_specs_[pos.system_spec_index_].pscore_)
+ return robust_scm2double (ps->layout ()->lookup_variable (penalty_sym), 0.0);
+
+ return robust_scm2double (book_->paper_->lookup_variable (penalty_sym), 0.0);
+}
+
+// If systems_per_page_ is positive, we don't really try to space on N
+// or N+1 pages; see the comment to space_systems_on_n_pages.
+Page_spacing_result
+Page_breaking::space_systems_on_n_or_one_more_pages (vsize configuration, vsize n, vsize first_page_num,
+ Real penalty_for_fewer_pages)
+{
+ Page_spacing_result n_res;
+ Page_spacing_result m_res;
+
+ if (systems_per_page_ > 0)
+ {
+ Page_spacing_result ret = space_systems_with_fixed_number_per_page (configuration, first_page_num);
+ ret.demerits_ += (ret.force_.size () == n || ret.force_.size () == (n-1)) ? 0 : BAD_SPACING_PENALTY;
+ return ret;
+ }
+
+ cache_line_details (configuration);
+ vsize min_p_count = min_page_count (configuration, first_page_num);
+ bool valid_n = n >= min_p_count || n <= cached_line_details_.size ();
+
+ if (!valid_n)
+ programming_error ("both page counts are out of bounds");
+
+ if (n == 1 && valid_n)
+ {
+ bool rag = ragged () || (is_last () && ragged_last ());
+ Real height = page_height (first_page_num, is_last ());
+
+ if (1 >= min_p_count)
+ n_res = space_systems_on_1_page (cached_line_details_, height, rag);
+ if (1 < cached_line_details_.size ())
+ m_res = space_systems_on_2_pages (configuration, first_page_num);
+ }
+ else
+ {
+ Page_spacer ps (cached_line_details_, first_page_num, this);
+
+ if (n >= min_p_count || !valid_n)
+ n_res = ps.solve (n);
+ if (n < cached_line_details_.size () || !valid_n)
+ m_res = ps.solve (n+1);
+ }
+
+ m_res = finalize_spacing_result (configuration, m_res);
+ n_res = finalize_spacing_result (configuration, n_res);
+
+ Real page_spacing_weight = robust_scm2double (book_->paper_->c_variable ("page-spacing-weight"), 10);
+ n_res.demerits_ += penalty_for_fewer_pages * page_spacing_weight;
+
+ if (n_res.force_.size ())
+ n_res.force_.back () += penalty_for_fewer_pages;
+
+ return (m_res.demerits_ < n_res.demerits_) ? m_res : n_res;
+}
+
+Page_spacing_result
+Page_breaking::space_systems_on_best_pages (vsize configuration, vsize first_page_num)
+{
+ if (systems_per_page_ > 0)
+ return space_systems_with_fixed_number_per_page (configuration, first_page_num);
+
+ cache_line_details (configuration);
+ Page_spacer ps (cached_line_details_, first_page_num, this);
+
+ return finalize_spacing_result (configuration, ps.solve ());
+}
+
+Page_spacing_result
+Page_breaking::space_systems_with_fixed_number_per_page (vsize configuration,
+ vsize first_page_num)
+{
+ Page_spacing_result res;
+ Page_spacing space (page_height (first_page_num, false), this);
+ vsize line = 0;
+ vsize page = 0;
+ vsize page_first_line = 0;
+
+ cache_line_details (configuration);
+ while (line < cached_line_details_.size ())
+ {
+ page++;
+ space.clear ();
+ space.resize (page_height (first_page_num + page, false));
+
+ int system_count_on_this_page = 0;
+ while (system_count_on_this_page < systems_per_page_
+ && line < cached_line_details_.size ())
+ {
+ Line_details const &cur_line = cached_line_details_[line];
+ space.append_system (cur_line);
+ system_count_on_this_page += cur_line.compressed_nontitle_lines_count_;
+ line++;
+
+ if (cur_line.page_permission_ == ly_symbol2scm ("force"))
+ break;
+ }
+
+ res.systems_per_page_.push_back (line - page_first_line);
+
+ res.force_.push_back (space.force_);
+ res.penalty_ += cached_line_details_[line-1].page_penalty_;
+ if (system_count_on_this_page != systems_per_page_)
+ {
+ res.penalty_ += TERRIBLE_SPACING_PENALTY;
+ res.system_count_status_ |= ((system_count_on_this_page < systems_per_page_))
+ ? SYSTEM_COUNT_TOO_FEW : SYSTEM_COUNT_TOO_MANY;
+ }
+
+ page_first_line = line;
+ }
+
+ /* Recalculate forces for the last page because we know now that is
+ really the last page. */
+ space.resize (page_height (first_page_num + page, true));
+ res.force_.back () = space.force_;
+ return finalize_spacing_result (configuration, res);
+}
+
+Page_spacing_result
+Page_breaking::pack_systems_on_least_pages (vsize configuration, vsize first_page_num)
+{
+ // TODO: add support for min/max-systems-per-page.
+ Page_spacing_result res;
+ vsize page = 0;
+ vsize page_first_line = 0;
+ Page_spacing space (page_height (first_page_num, false), this);
+
+ cache_line_details (configuration);
+ for (vsize line = 0; line < cached_line_details_.size (); line++)
+ {
+ Real prev_force = space.force_;
+ space.append_system (cached_line_details_[line]);
+ if ((line > page_first_line)
+ && (isinf (space.force_)
+ || ((line > 0)
+ && (cached_line_details_[line-1].page_permission_ == ly_symbol2scm ("force")))))
+ {
+ res.systems_per_page_.push_back (line - page_first_line);
+ res.force_.push_back (prev_force);
+ res.penalty_ += cached_line_details_[line-1].page_penalty_;
+ page++;
+ space.resize (page_height (first_page_num + page, false));
+ space.clear ();
+ space.append_system (cached_line_details_[line]);
+ page_first_line = line;
+ }
+
+ if (line == cached_line_details_.size () - 1)
+ {
+ /* This is the last line */
+ /* When the last page height was computed, we did not know yet that it
+ * was the last one. If the systems put on it don't fit anymore, the last
+ * system is moved to a new page */
+ space.resize (page_height (first_page_num + page, true));
+ if ((line > page_first_line) && (isinf (space.force_)))
+ {
+ res.systems_per_page_.push_back (line - page_first_line);
+ res.force_.push_back (prev_force);
+ /* the last page containing the last line */
+ space.resize (page_height (first_page_num + page + 1, true));
+ space.clear ();
+ space.append_system (cached_line_details_[line]);
+ res.systems_per_page_.push_back (1);
+ res.force_.push_back (space.force_);
+ res.penalty_ += cached_line_details_[line-1].page_penalty_;
+ res.penalty_ += cached_line_details_[line].page_penalty_;
+ }
+ else
+ {
+ res.systems_per_page_.push_back (line + 1 - page_first_line);
+ res.force_.push_back (space.force_);
+ res.penalty_ += cached_line_details_[line].page_penalty_;
+ }
+ }
+ }
+ return finalize_spacing_result (configuration, res);
+}
+
+/* Calculate demerits and fix res.systems_per_page_ so that
+ it refers to the original line numbers, not the ones given by compress_lines (). */
+Page_spacing_result
+Page_breaking::finalize_spacing_result (vsize configuration, Page_spacing_result res)
+{
+ if (res.force_.empty ())
+ return res;
+
+ cache_line_details (configuration);
+ res.systems_per_page_ = uncompress_solution (res.systems_per_page_, cached_line_details_);
+
+ Real line_force = 0;
+ Real line_penalty = 0;
+ Real page_demerits = res.penalty_;
+ Real page_weighting = robust_scm2double (book_->paper_->c_variable ("page-spacing-weight"), 10);
+
+ for (vsize i = 0; i < uncompressed_line_details_.size (); i++)
+ {
+ line_force += uncompressed_line_details_[i].force_ * uncompressed_line_details_[i].force_;
+ line_penalty += uncompressed_line_details_[i].break_penalty_;
+ }
+
+ for (vsize i = 0; i < res.force_.size (); i++)
+ {
+ Real f = res.force_[i];
+
+ page_demerits += min(f*f, BAD_SPACING_PENALTY);
+ }
+
+ /* for a while we tried averaging page and line forces across pages instead
+ of summing them, but it caused a problem: if there is a single page
+ with a very bad page force (for example because of a forced page break),
+ the page breaker will put in a _lot_ of pages so that the bad force
+ becomes averaged out over many pages. */
+ res.demerits_ = line_force + line_penalty + page_demerits * page_weighting;
+ return res;
+
+}
+
+/* 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.
+
+ space_systems_on_1_page has a different calling convention than most of the
+ space_systems functions. This is because space_systems_on_1_page is (unlike
+ the other space_systems functions) sometimes called on subsets of a full
+ configuration. */
+Page_spacing_result
+Page_breaking::space_systems_on_1_page (vector<Line_details> const &lines, Real page_height, bool ragged)
+{
+ Page_spacing space (page_height, this);
+ Page_spacing_result ret;
+ int line_count = 0;
+
+ for (vsize i = 0; i < lines.size (); i++)
+ {
+ space.append_system (lines[i]);
+ line_count += lines[i].compressed_nontitle_lines_count_;
+ }
+
+ ret.systems_per_page_.push_back (lines.size ());
+ ret.force_.push_back (ragged ? min (space.force_, 0.0) : space.force_);
+ ret.penalty_ = line_count_penalty (line_count) + lines.back ().page_penalty_ + lines.back ().turn_penalty_;
+ ret.system_count_status_ |= line_count_status (line_count);
+
+ /* don't do finalize_spacing_result () because we are only an internal function */
+ return ret;
+}
+
+Page_spacing_result
+Page_breaking::space_systems_on_2_pages (vsize configuration, vsize first_page_num)
+{
+ Real page1_height = page_height (first_page_num, false);
+ Real page2_height = page_height (first_page_num + 1, is_last ());
+ bool ragged1 = ragged ();
+ bool ragged2 = ragged () || (is_last () && ragged_last ());
+
+ /* if there is a forced break, this reduces to 2 1-page problems */
+ cache_line_details (configuration);
+ for (vsize i = 0; i + 1 < cached_line_details_.size (); i++)
+ if (cached_line_details_[i].page_permission_ == ly_symbol2scm ("force"))
+ {
+ vector<Line_details> lines1 (cached_line_details_.begin (), cached_line_details_.begin () + i + 1);
+ vector<Line_details> lines2 (cached_line_details_.begin () + i + 1, cached_line_details_.end ());
+ Page_spacing_result p1 = space_systems_on_1_page (lines1, page1_height, ragged1);
+ Page_spacing_result p2 = space_systems_on_1_page (lines2, page2_height, ragged2);
+
+ p1.systems_per_page_.push_back (p2.systems_per_page_[0]);
+ p1.force_.push_back (p2.force_[0]);
+ p1.penalty_ += p2.penalty_ - cached_line_details_[i].turn_penalty_;
+ p1.system_count_status_ |= p2.system_count_status_;
+ return p1;
+ }
+
+ vector<Real> page1_force;
+ vector<Real> page2_force;
+
+ // page1_penalty and page2_penalty store the penalties based
+ // on min-systems-per-page and max-systems-per-page.
+ vector<Real> page1_penalty;
+ vector<Real> page2_penalty;
+
+ // page1_status and page2_status keep track of whether the min-systems-per-page
+ // and max-systems-per-page constraints are satisfied.
+ vector<int> page1_status;
+ vector<int> page2_status;
+
+ Page_spacing page1 (page1_height, this);
+ Page_spacing page2 (page2_height, this);
+ int page1_line_count = 0;
+ int page2_line_count = 0;
+
+ page1_force.resize (cached_line_details_.size () - 1, infinity_f);
+ page2_force.resize (cached_line_details_.size () - 1, infinity_f);
+ page1_penalty.resize (cached_line_details_.size () - 1, infinity_f);
+ page2_penalty.resize (cached_line_details_.size () - 1, infinity_f);
+ page1_status.resize (cached_line_details_.size () - 1, 0);
+ page2_status.resize (cached_line_details_.size () - 1, 0);
+
+ /* find the page 1 and page 2 forces for each page-breaking position */
+ for (vsize i = 0; i < page1_force.size (); i++)
+ {
+ page1.append_system (cached_line_details_[i]);
+ page2.prepend_system (cached_line_details_[cached_line_details_.size () - 1 - i]);
+ page1_line_count += cached_line_details_[i].compressed_nontitle_lines_count_;
+ page2_line_count += cached_line_details_[cached_line_details_.size () - 1 - i].compressed_nontitle_lines_count_;
+
+ page1_force[i] = (ragged1 && page1.force_ < 0 && i > 0) ? infinity_f : page1.force_;
+ page1_penalty[i] = line_count_penalty (page1_line_count);
+ page1_status[i] = line_count_status (page1_line_count);
+
+ if (ragged2)
+ page2_force[page2_force.size () - 1 - i] =
+ (page2.force_ < 0 && i + 1 < page1_force.size ()) ? infinity_f : 0;
+ else
+ page2_force[page2_force.size () - 1 - i] = page2.force_;
+ page2_penalty[page2_penalty.size () - 1 - i] = line_count_penalty (page2_line_count);
+ page2_status[page2_penalty.size () - 1 - i] = line_count_status (page2_line_count);
+ }
+
+ /* find the position that minimises the sum of the page forces */
+ vsize best_sys_count = 1;
+ Real best_demerits = infinity_f;
+ for (vsize i = 0; i < page1_force.size (); i++)
+ {
+ Real f = page1_force[i] * page1_force[i] + page2_force[i] * page2_force[i];
+
+ // NOTE: we treat max-systems-per-page and min-systems-per-page as soft
+ // constraints. That is, we penalize harshly when they don't happen
+ // but we don't completely reject.
+ Real dem = f
+ + page1_penalty[i] + page2_penalty[i]
+ + cached_line_details_[i+1].page_penalty_
+ + cached_line_details_.back ().page_penalty_ + cached_line_details_.back ().turn_penalty_;
+ if (dem < best_demerits)
+ {
+ best_demerits = dem;
+ best_sys_count = i+1;
+ }
+ }
+
+ Page_spacing_result ret;
+ ret.systems_per_page_.push_back (best_sys_count);
+ ret.systems_per_page_.push_back (cached_line_details_.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.system_count_status_ = page1_status[best_sys_count-1] | page2_status[best_sys_count-1];
+ ret.penalty_ = cached_line_details_[best_sys_count-1].page_penalty_
+ + cached_line_details_.back ().page_penalty_
+ + cached_line_details_.back ().turn_penalty_
+ + page1_penalty[best_sys_count-1] + page2_penalty[best_sys_count-1];
+
+ /* don't do finalize_spacing_result () because we are only an internal function */
+ return ret;
+}
+
+bool
+Page_breaking::all_lines_stretched (vsize configuration)
+{
+ cache_line_details (configuration);
+ for (vsize i = 0; i < cached_line_details_.size (); i++)
+ if (cached_line_details_[i].force_ < 0)
+ return false;
+
+ return true;
+}
+
+Page_breaking::Line_division
+Page_breaking::current_configuration (vsize configuration_index) const
+{
+ return current_configurations_[configuration_index];
+}
+
+bool
+Page_breaking::is_last () const
+{
+ return current_end_breakpoint_ == last_break_position ();
+}
+
+bool
+Page_breaking::ends_score () const
+{
+ return breaks_[current_end_breakpoint_].score_ender_;
+}
+
+vsize
+Page_breaking::last_break_position () const
+{
+ return breaks_.size () - 1;
+}
+
+// This gives the minimum distance between the top of the
+// printable area (ie. the bottom of the top-margin) and
+// the extent box of the topmost system.
+Real
+Page_breaking::min_whitespace_at_top_of_page (Line_details const &line) const
+{
+ SCM first_system_spacing = book_->paper_->c_variable ("top-system-spacing");
+ if (line.title_)
+ first_system_spacing = book_->paper_->c_variable ("top-markup-spacing");
+
+ Real min_distance = -infinity_f;
+ Real padding = 0;
+
+ Page_layout_problem::read_spacing_spec (first_system_spacing,
+ &min_distance,
+ ly_symbol2scm ("minimum-distance"));
+ Page_layout_problem::read_spacing_spec (first_system_spacing,
+ &padding,
+ ly_symbol2scm ("padding"));
+
+ // FIXME: take into account the height of the header
+ Real translate = max (line.shape_.begin_[UP], line.shape_.rest_[UP]);
+ return max (0.0, max (padding, min_distance - translate));
+}
+
+Real
+Page_breaking::min_whitespace_at_bottom_of_page (Line_details const &line) const
+{
+ SCM last_system_spacing = book_->paper_->c_variable ("last-bottom-spacing");
+ Real min_distance = -infinity_f;
+ Real padding = 0;
+
+ Page_layout_problem::read_spacing_spec (last_system_spacing,
+ &min_distance,
+ ly_symbol2scm ("minimum-distance"));
+ Page_layout_problem::read_spacing_spec (last_system_spacing,
+ &padding,
+ ly_symbol2scm ("padding"));
+
+ // FIXME: take into account the height of the footer
+ Real translate = min (line.shape_.begin_[DOWN], line.shape_.rest_[DOWN]);
+ return max (0.0, max (padding, min_distance + translate));
+}
+
+int
+Page_breaking::orphan_penalty () const
+{
+ return orphan_penalty_;
+}