source file of the GNU LilyPond music typesetter
- (c) 2006 Joe Neeman <joeneeman@gmail.com>
+ (c) 2006--2008 Joe Neeman <joeneeman@gmail.com>
*/
#include "page-spacing.hh"
#include "matrix.hh"
+#include "page-breaking.hh"
#include "warn.hh"
-/*
- A much simplified rods-and-springs problem.
- */
-struct Page_spacing
-{
- Real force_;
- Real page_height_;
- Real rod_height_;
- Real spring_len_;
- Real inverse_spring_k_;
-
- Line_details last_line_;
-
- Page_spacing (Real page_height)
- {
- page_height_ = page_height;
- clear ();
- }
-
- void calc_force ();
-
- void append_system (const Line_details &line);
- void prepend_system (const Line_details &line);
- void clear ();
-};
-
void
Page_spacing::calc_force ()
{
- if (rod_height_ + last_line_.bottom_padding_ >= page_height_ || !inverse_spring_k_)
+ /* 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_;
+
+ if (rod_height_ + last_line_.bottom_padding_ >= height)
force_ = infinity_f;
else
- force_ = (page_height_ - rod_height_ - last_line_.bottom_padding_ - spring_len_) / inverse_spring_k_;
+ force_ = (height - rod_height_ - last_line_.bottom_padding_ - spring_len_)
+ / max (0.1, inverse_spring_k_);
+}
+
+void
+Page_spacing::resize (Real new_height)
+{
+ page_height_ = new_height;
+ calc_force ();
}
void
Page_spacing::append_system (const Line_details &line)
{
+ if (!rod_height_)
+ first_line_ = line;
+
rod_height_ += last_line_.padding_;
rod_height_ += line.extent_.length ();
spring_len_ += line.space_;
inverse_spring_k_ += line.inverse_hooke_;
+ first_line_ = line;
+
calc_force ();
}
inverse_spring_k_ = 0;
}
-/* 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 (i < orig.size () - 1 && orig[i].page_permission_ == SCM_EOL)
- {
- Line_details compressed = orig[i+1];
- compressed.extent_[DOWN] = orig[i].extent_[DOWN];
- compressed.extent_[UP] = orig[i].extent_[UP] + orig[i+1].extent_.length () + orig[i].padding_;
- compressed.space_ += orig[i].space_;
- compressed.inverse_hooke_ += orig[i].inverse_hooke_;
-
- /* we don't need the force_ field for the vertical spacing,
- so we use force_ = -1 to signal that the line was compressed
- (and force_ = +1 otherwise).
- This makes uncompression much easier. */
- compressed.force_ = -1;
- ret.push_back (compressed);
- i++;
- }
- else
- {
- ret.push_back (orig[i]);
- ret.back ().force_ = 1;
- }
- }
- 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++)
- if (compressed[j].force_ < 0)
- compressed_count++;
-
- ret.push_back (systems_per_page[i] + compressed_count);
- start_sys += systems_per_page[i];
- }
- return ret;
-}
-
-/* the cases for page_count = 1 or 2 can be done in O(n) time. Since they
- are by far the most common cases, we have special functions for them */
-static Spacing_result
-space_systems_on_1_page (vector<Line_details> const &lines, Real page_height, bool ragged)
-{
- Page_spacing space (page_height);
- Spacing_result ret;
- for (vsize i = 0; i < lines.size (); i++)
- space.append_system (lines[i]);
-
- ret.systems_per_page_.push_back (lines.size ());
- ret.force_.push_back (ragged ? min (space.force_, 0.0) : space.force_);
- ret.penalty_ = lines.back ().page_penalty_ + lines.back ().turn_penalty_;
- ret.demerits_ = ret.force_.back () * ret.force_.back () + ret.penalty_;
-
- return ret;
-}
-
-static Spacing_result
-space_systems_on_2_pages (vector<Line_details> const &lines,
- Real page_height,
- bool ragged,
- bool ragged_last)
-{
- /* if there is a forced break, this reduces to 2 1-page problems */
- for (vsize i = 0; i < lines.size () - 1; i++)
- if (lines[i].page_permission_ == ly_symbol2scm ("force"))
- {
- vector<Line_details> lines1 (lines.begin (), lines.begin () + i + 1);
- vector<Line_details> lines2 (lines.begin () + i + 1, lines.end ());
- Spacing_result p1 = space_systems_on_1_page (lines1, page_height, ragged);
- Spacing_result p2 = space_systems_on_1_page (lines2, page_height, ragged || ragged_last);
-
- p1.systems_per_page_.push_back (p2.systems_per_page_[0]);
- p1.force_.push_back (p2.force_[0]);
- p1.penalty_ += p2.penalty_ - lines[i].turn_penalty_;
- p1.demerits_ += p2.demerits_ - lines[i].turn_penalty_;
- return p1;
- }
-
- vector<Real> page1_force;
- vector<Real> page2_force;
- Page_spacing page1 (page_height);
- Page_spacing page2 (page_height);
-
- page1_force.resize (lines.size () - 1, infinity_f);
- page2_force.resize (lines.size () - 1, infinity_f);
-
- for (vsize i = 0; i < page1_force.size (); i++)
- {
- page1.append_system (lines[i]);
- page2.prepend_system (lines[lines.size () - 1 - i]);
- page1_force[i] = (ragged && page1.force_ < 0 && i > 0) ? infinity_f : page1.force_;
-
- if (ragged || ragged_last)
- page2_force[page2_force.size () - 1 - i] =
- (page2.force_ < 0 && i < page1_force.size () - 1) ? infinity_f : 0;
- else
- page2_force[page2_force.size () - 1 - i] = page2.force_;
- }
-
- vsize best_sys_count = 1;
- Real best_demerits = infinity_f;
- for (vsize i = 0; i < page1_force.size (); i++)
- {
- Real dem = page1_force[i] * page1_force[i]
- + page2_force[i] * page2_force[i]
- + lines[i+1].page_penalty_
- + lines.back ().page_penalty_ + lines.back ().turn_penalty_;
- if (dem < best_demerits)
- {
- best_demerits = dem;
- best_sys_count = i+1;
- }
- }
-
- Spacing_result ret;
- ret.systems_per_page_.push_back (best_sys_count);
- ret.systems_per_page_.push_back (lines.size () - best_sys_count);
- ret.force_.push_back (page1_force[best_sys_count-1]);
- ret.force_.push_back (page2_force[best_sys_count-1]);
- ret.penalty_ = lines[best_sys_count-1].page_penalty_
- + lines.back ().page_penalty_
- + lines.back ().turn_penalty_;
- ret.demerits_ = best_demerits;
-
- return ret;
-}
-
-Page_spacer::Page_spacer (vector<Line_details> const &lines, Real page_height, bool ragged, bool ragged_last)
+Page_spacer::Page_spacer (vector<Line_details> const &lines, vsize first_page_num, Page_breaking const *breaker)
: lines_ (lines)
{
- page_height_ = page_height;
+ first_page_num_ = first_page_num;
+ breaker_ = breaker;
max_page_count_ = 0;
- ragged_ = ragged;
- ragged_last_ = ragged_last;
+ ragged_ = breaker->ragged ();
+ ragged_last_ = breaker->is_last () && breaker->ragged_last ();
}
-Spacing_result
+Page_spacing_result
Page_spacer::solve (vsize page_count)
{
if (page_count > max_page_count_)
resize (page_count);
- Spacing_result ret;
- ret.force_.resize (page_count);
- ret.systems_per_page_.resize (page_count);
+ Page_spacing_result ret;
vsize system = lines_.size () - 1;
+ vsize extra_systems = 0;
+ vsize extra_pages = 0;
if (isinf (state_.at (system, page_count-1).demerits_))
{
programming_error ("tried to space systems on a bad number of pages");
- return Spacing_result (); /* bad number of pages */
+ /* Usually, this means that we tried to cram too many systems into
+ to few pages. To avoid crashing, we look for the largest number of
+ systems that we can fit properly onto the right number of pages.
+ All the systems that don't fit get tacked onto the last page.
+ */
+ vsize i;
+ for (i = system; isinf (state_.at (i, page_count-1).demerits_) && i; i--)
+ ;
+
+ if (i)
+ {
+ extra_systems = system - i;
+ system = i;
+ }
+ else
+ {
+ /* try chopping off pages from the end */
+ vsize j;
+ for (j = page_count; j && isinf (state_.at (system, j-1).demerits_); j--)
+ ;
+
+ if (j)
+ {
+ extra_pages = page_count - j;
+ page_count = j;
+ }
+ else
+ return Page_spacing_result (); /* couldn't salvage it -- probably going to crash */
+ }
}
+ ret.force_.resize (page_count);
+ ret.systems_per_page_.resize (page_count);
ret.penalty_ = state_.at (system, page_count-1).penalty_
+ lines_.back ().page_penalty_ + lines_.back ().turn_penalty_;
+ ret.demerits_ = 0;
for (vsize p = page_count; p--;)
{
assert (system != VPOS);
ret.systems_per_page_[p] = system - ps.prev_;
system = ps.prev_;
}
+
+ if (extra_systems)
+ {
+ ret.systems_per_page_.back () += extra_systems;
+ ret.demerits_ += 200000;
+ }
+ if (extra_pages)
+ {
+ ret.force_.insert (ret.force_.end (), extra_pages, 200000);
+ ret.systems_per_page_.insert (ret.systems_per_page_.end (), extra_pages, 0);
+ ret.demerits_ += 200000;
+ }
+
+
ret.demerits_ += ret.penalty_;
return ret;
}
bool
Page_spacer::calc_subproblem (vsize page, vsize line)
{
- Page_spacing space (page_height_);
+ bool last = line == lines_.size () - 1;
+ Page_spacing space (breaker_->page_height (page + first_page_num_, last),
+ breaker_->page_top_space ());
Page_spacing_node &cur = state_.at (line, page);
- bool ragged = ragged_ || (ragged_last_ && line == lines_.size () - 1);
+ bool ragged = ragged_ || (ragged_last_ && last);
for (vsize page_start = line+1; page_start > page && page_start--;)
{
if (page > 0 || page_start == 0)
{
- if (line == lines_.size () - 1 && ragged_last_ && space.force_ > 0)
+ 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 */
return !isinf (cur.demerits_);
}
-static vsize
-min_page_count (vector<Line_details> const &lines, Real page_height, bool ragged)
-{
- vsize ret = 1;
- Real cur_rod_height = 0;
-
- for (vsize i = 0; i < lines.size (); i++)
- {
- Real ext_len = lines[i].extent_.length ();
- Real next_height = cur_rod_height + ext_len
- + (ragged ? lines[i].space_ : 0)
- + ((cur_rod_height > 0) ? lines[i-1].padding_: 0);
-
- if ((next_height > page_height && cur_rod_height > 0)
- || (i > 0 && lines[i-1].page_permission_ == ly_symbol2scm ("force")))
- {
- ret++;
- cur_rod_height = ext_len + (ragged ? lines[i].space_ : 0);
- }
- else
- cur_rod_height = next_height;
- }
- return ret;
-}
-
-Spacing_result
-space_systems_on_min_pages (vector<Line_details> const &lines,
- Real page_height,
- Real odd_pages_penalty,
- bool ragged,
- bool ragged_last)
-{
- vector<Line_details> compressed_lines = compress_lines (lines);
- vsize min_p_count = min_page_count (compressed_lines, page_height, ragged);
- Spacing_result ret;
-
- if (min_p_count == 1)
- {
- Spacing_result candidate1 = space_systems_on_1_page (compressed_lines, page_height, ragged || ragged_last);
- candidate1.force_.back () += odd_pages_penalty;
- candidate1.demerits_ += odd_pages_penalty;
- if (compressed_lines.size () == 1)
- ret = candidate1;
- else
- {
- Spacing_result candidate2 = space_systems_on_2_pages (compressed_lines, page_height, ragged, ragged_last);
- ret = (candidate1.demerits_ < candidate2.demerits_) ?
- candidate1 : candidate2;
- }
- }
- else if (min_p_count == 2)
- ret = space_systems_on_2_pages (compressed_lines, page_height, ragged, ragged_last);
- else
- {
- Page_spacer ps (compressed_lines, page_height, ragged, ragged_last);
- Spacing_result candidate1 = ps.solve (min_p_count);
- if (min_p_count % 2 == 0)
- ret = candidate1;
- else
- {
- candidate1.force_.back () += odd_pages_penalty;
- candidate1.demerits_ += odd_pages_penalty;
-
- if (min_p_count == compressed_lines.size ())
- ret = candidate1;
- else
- {
- Spacing_result candidate2 = ps.solve (min_p_count + 1);
- ret = (candidate1.demerits_ < candidate2.demerits_) ?
- candidate1 : candidate2;
- }
- }
- }
- ret.systems_per_page_ = uncompress_solution (ret.systems_per_page_, compressed_lines);
- return ret;
-}
-
-Spacing_result
-space_systems_on_best_pages (vector<Line_details> const &lines,
- Real page_height,
- Real odd_pages_penalty,
- bool ragged,
- bool ragged_last)
-{
- vector<Line_details> compressed_lines = compress_lines (lines);
- vsize min_p_count = min_page_count (compressed_lines, page_height, ragged);
-
- Page_spacer ps (compressed_lines, page_height, ragged, ragged_last);
- Spacing_result best = ps.solve (min_p_count);
- best.force_.back () += (min_p_count % 2) ? odd_pages_penalty : 0;
- best.demerits_ += (min_p_count % 2) ? odd_pages_penalty : 0;
-
- for (vsize i = min_p_count+1; i <= compressed_lines.size (); i++)
- {
- Spacing_result cur = ps.solve (i);
- cur.demerits_ += (i % 2) ? odd_pages_penalty : 0;
- if (cur.demerits_ < best.demerits_)
- best = cur;
- }
-
- best.systems_per_page_ = uncompress_solution (best.systems_per_page_, compressed_lines);
- return best;
-}
projects / lilypond.git / blobdiff