/*
- page-spacing.hh -- routines for spacing systems
- vertically across pages
+ This file is part of LilyPond, the GNU music typesetter.
- source file of the GNU LilyPond music typesetter
+ Copyright (C) 2006--2010 Joe Neeman <joeneeman@gmail.com>
- (c) 2006 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/>.
*/
#ifndef PAGE_SPACING_HH
#define PAGE_SPACING_HH
#include "constrained-breaking.hh"
+#include "page-spacing-result.hh"
+
+/* This is a penalty that we add whenever a page breaking solution
+ is not bad enough to completely discard, but bad enough that
+ it is worse than any "proper" solution. For example, if we didn't
+ manage to fit systems on the desired number of pages or if there was
+ too big for a page.
+
+ This constant is large enough that it dominates any reasonable penalty,
+ but small enough that nothing will overflow to infinity (so that we
+ can still distinguish bad spacings by the number of BAD_SPACING_PENALTYs
+ that they incur.
+
+ BAD_SPACING_PENALTY is for occasions where the spacing is bad.
+ TERRIBLE_SPACING_PENALTY is for when we are disregarding a user override
+ (for example, we are failing to satisfy min-systems-per-page). These user
+ overrides are more important than getting good spacing, so they get a
+ larger penalty.
+*/
+const Real BAD_SPACING_PENALTY = 1e6;
+const Real TERRIBLE_SPACING_PENALTY = 1e8;
+
-struct Spacing_result {
- vector<vsize> systems_per_page_;
- vector<Real> force_;
- Real penalty_;
- Real demerits_;
+/* for page_count > 2, we use a dynamic algorithm similar to
+ constrained-breaking -- we have a class that stores the intermediate
+ calculations so they can be reused for querying different page counts.
+*/
+class Page_spacer
+{
+public:
+ Page_spacer (vector<Line_details> const &lines, vsize first_page_num, Page_breaking const*);
+ Page_spacing_result solve (vsize page_count);
+ Page_spacing_result solve ();
- Spacing_result ()
+private:
+ struct Page_spacing_node
{
- penalty_ = 0;
- demerits_ = 0;
- }
+ Page_spacing_node ()
+ {
+ demerits_ = infinity_f;
+ force_ = infinity_f;
+ penalty_ = infinity_f;
+ prev_ = VPOS;
+ system_count_status_ = SYSTEM_COUNT_OK;
+ page_ = 0;
+ }
+
+ Real demerits_;
+ Real force_;
+ Real penalty_;
+ vsize prev_;
+ vsize page_;
+ int system_count_status_;
+ };
+
+ Page_breaking const *breaker_;
+ vsize first_page_num_;
+ vector<Line_details> lines_;
+
+ // If a page-count is requested, we use state_, which
+ // is indexed by page*system, for our dynamic programming
+ // intermediate storage. Otherwise, we use simple_state_,
+ // which is indexed only by system.
+ Matrix<Page_spacing_node> state_;
+ vector<Page_spacing_node> simple_state_;
+ vsize max_page_count_;
+
+ bool ragged_;
+ bool ragged_last_;
+
+ void resize (vsize page_count);
+ bool calc_subproblem (vsize page, vsize lines);
};
-Spacing_result
-space_systems_on_min_pages (vector<Line_details> const&,
- Real page_height,
- Real odd_pages_penalty);
-Spacing_result
-space_systems_on_best_pages (vector<Line_details> const&,
- Real page_height,
- Real odd_pages_penalty);
+struct Page_spacing
+{
+ Real force_;
+ Real page_height_;
+ Real rod_height_;
+ Real spring_len_;
+ Real inverse_spring_k_;
+
+ Line_details last_line_;
+ Line_details first_line_;
+ Page_breaking const *breaker_;
+
+ Page_spacing (Real page_height, Page_breaking const *breaker)
+ {
+ page_height_ = page_height;
+ breaker_ = breaker;
+ clear ();
+ }
+
+ void calc_force ();
+ void resize (Real new_height);
+ void append_system (const Line_details &line);
+ void prepend_system (const Line_details &line);
+ void clear ();
+};
#endif /* PAGE_SPACING_HH */