source file of the GNU LilyPond music typesetter
- (c) 2006--2007 Joe Neeman <joeneeman@gmail.com>
+ (c) 2006--2009 Joe Neeman <joeneeman@gmail.com>
+*/
+
+/*
+ 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"
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;
+ 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
{
int compressed_count = 0;
for (vsize j = start_sys; j < start_sys + systems_per_page[i]; j++)
- compressed_count += (int)compressed[j].force_;
+ compressed_count += compressed[j].compressed_lines_count_ - 1;
ret.push_back (systems_per_page[i] + compressed_count);
start_sys += systems_per_page[i];
Page_breaking::Page_breaking (Paper_book *pb, Break_predicate is_break)
{
book_ = pb;
+ system_count_ = 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));
+
+ 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);
}
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,
return scm_append (scm_reverse (ret));
}
+SCM
+Page_breaking::make_page (int page_num, bool last) const
+{
+ 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");
+
+ make_page_scm = scm_variable_ref (make_page_scm);
+
+ 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));
+}
+
Real
Page_breaking::page_height (int page_num, bool last) const
{
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");
- SCM make_page = scm_c_module_lookup (mod, "make-page");
-
calc_height = scm_variable_ref (calc_height);
- make_page = scm_variable_ref (make_page);
- 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"));
+ return scm_to_double (height);
}
SCM
}
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 ();
+ 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)
+{
int first_page_number
= robust_scm2int (book_->paper_->c_variable ("first-page-number"), 1);
SCM ret = SCM_EOL;
- SCM label_page_table = 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 rag = scm_from_bool (ragged () || (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,
- rag, last, SCM_UNDEFINED));
+ SCM config = get_page_configuration (lines, page_num, rag, bookpart_last_page);
+
+ systems_and_configs = scm_cons (scm_cons (lines, config), systems_and_configs);
+ systems = scm_list_tail (systems, line_count);
+ }
+
+ // 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;
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),
+ label_page_table = scm_cons (scm_cons (scm_car (lbls), page_num_scm),
label_page_table);
}
- scm_apply_1 (page_stencil, page, SCM_EOL);
ret = scm_cons (page, ret);
- systems = scm_list_tail (systems, line_count);
+ --page_num;
}
- book_->paper_->set_variable (ly_symbol2scm ("label-page-table"), label_page_table);
- ret = scm_reverse (ret);
+ book_->top_paper ()->set_variable (ly_symbol2scm ("label-page-table"), label_page_table);
return ret;
}
Line_division lower_bound,
Line_division upper_bound)
{
+ system_count_ = system_count;
current_chunks_ = chunk_list (start, end);
current_start_breakpoint_ = start;
current_end_breakpoint_ = 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++)
}
else
div.push_back (1);
+
+ system_count_ += div.back ();
}
current_configurations_.clear ();
current_configurations_.push_back (div);
{
if (cached_configuration_index_ != configuration_index)
{
- SCM padding_scm = book_->paper_->c_variable ("page-breaking-between-system-padding");
- if (!scm_is_number (padding_scm))
- padding_scm = book_->paper_->c_variable ("between-system-padding");
- Real padding = robust_scm2double (padding_scm, 0.0);
+ cached_configuration_index_ = configuration_index;
+ Real padding = 0;
+ SCM spacing_spec = book_->paper_->c_variable ("between-system-spacing");
+ SCM page_breaking_spacing_spec = book_->paper_->c_variable ("page-breaking-between-system-spacing");
+ Page_layout_problem::read_spacing_spec (spacing_spec, &padding, ly_symbol2scm ("padding"));
+ Page_layout_problem::read_spacing_spec (page_breaking_spacing_spec, &padding, ly_symbol2scm ("padding"));
Line_division &div = current_configurations_[configuration_index];
uncompressed_line_details_.clear ();
{
assert (div[i] == 1);
uncompressed_line_details_.push_back (Line_details (system_specs_[sys].prob_));
- uncompressed_line_details_.back ().padding_ = padding;
+ uncompressed_line_details_.back ().padding_ =
+ robust_scm2double (system_specs_[sys].prob_->get_property ("next-padding"),
+ padding);
}
}
cached_line_details_ = compress_lines (uncompressed_line_details_);
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 = cached_line_details_[i].extent_.length ();
Real next_rod_height = cur_rod_height + ext_len
+ ((cur_rod_height > 0) ? cached_line_details_[i].padding_: 0);
- Real next_spring_height = cur_spring_height + line_space (cached_line_details_[i]);
- Real next_height = next_rod_height + (ragged () ? next_spring_height : 0);
-
+ 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 ((next_height > cur_page_height && cur_rod_height > 0)
+ 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 = ext_len;
- cur_spring_height = line_space (cached_line_details_[i]);
+ 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;
}
}
*/
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 (cur_height > cur_page_height
+ 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 ().extent_.length ())
ret++;
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;
- assert (n >= min_page_count (configuration, first_page_num));
+
+ 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);
- if (n > cached_line_details_.size ())
- return Page_spacing_result ();
- if (n == 1)
+ 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)
+ else if (n == 2 && valid_n)
ret = space_systems_on_2_pages (configuration, first_page_num);
else
{
Real
Page_breaking::blank_page_penalty () const
{
- SCM penalty_sym = is_last () ? ly_symbol2scm ("blank-last-page-force") : ly_symbol2scm ("blank-page-force");
+ 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)
{
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 (n == 1)
+ 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 ());
{
Page_spacer ps (cached_line_details_, first_page_num, this);
- if (n >= min_p_count)
+ if (n >= min_p_count || !valid_n)
n_res = ps.solve (n);
- if (n < cached_line_details_.size ())
+ if (n < cached_line_details_.size () || !valid_n)
m_res = ps.solve (n+1);
}
return finalize_spacing_result (configuration, best);
}
+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
Real line_force = 0;
Real line_penalty = 0;
- Real page_force = 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++)
for (vsize i = 0; i < res.force_.size (); i++)
{
Real f = res.force_[i];
- if (isinf (f) && res.systems_per_page_[i] == 1)
- f = 20000;
- page_force += f * f;
+ page_demerits += min(f*f, BAD_SPACING_PENALTY);
}
/* for a while we tried averaging page and line forces across pages instead
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_force + res.penalty_) * page_weighting;
+ res.demerits_ = line_force + line_penalty + page_demerits * page_weighting;
return res;
}
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);
+ 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]);
+ {
+ 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_ = lines.back ().page_penalty_ + lines.back ().turn_penalty_;
+ 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;
vector<Real> page1_force;
vector<Real> page2_force;
- Page_spacing page1 (page1_height);
- Page_spacing page2 (page2_height);
+
+ // 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 */
for (vsize i = 0; i < page1_force.size (); i++)
{
Real f = page1_force[i] * page1_force[i] + page2_force[i] * page2_force[i];
- Real uneven = 2 * (page1_force[i] - page2_force[i]);
- Real dem = uneven * uneven + f
+
+ // 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)
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_;
+ + 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;
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 ("first-system-spacing");
+ if (line.title_)
+ first_system_spacing = book_->paper_->c_variable ("first-system-title-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
+ return max (0.0, max (padding, min_distance - line.extent_[UP]));
+}
+
+Real
+Page_breaking::min_whitespace_at_bottom_of_page (Line_details const &line) const
+{
+ SCM last_system_spacing = book_->paper_->c_variable ("last-system-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
+ return max (0.0, max (padding, min_distance + line.extent_[DOWN]));
+}
projects / lilypond.git / blobdiff