2 This file is part of LilyPond, the GNU music typesetter.
4 Copyright (C) 2006--2010 Joe Neeman <joeneeman@gmail.com>
6 LilyPond is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 LilyPond is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
20 #include "international.hh"
21 #include "optimal-page-breaking.hh"
22 #include "output-def.hh"
23 #include "page-spacing.hh"
24 #include "paper-book.hh"
25 #include "paper-score.hh"
29 Optimal_page_breaking::Optimal_page_breaking (Paper_book *pb)
30 : Page_breaking (pb, 0, 0)
34 Optimal_page_breaking::~Optimal_page_breaking ()
38 extern bool debug_page_breaking_scoring;
41 Optimal_page_breaking::solve ()
43 vsize end = last_break_position ();
44 vsize max_sys_count = max_system_count (0, end);
45 vsize first_page_num = robust_scm2int (book_->paper_->c_variable ("first-page-number"), 1);
47 set_to_ideal_line_configuration (0, end);
49 Page_spacing_result best;
50 SCM forced_page_count = book_->paper_->c_variable ("page-count");
51 vsize page_count = robust_scm2int (forced_page_count, 1);
52 Line_division ideal_line_division = current_configuration (0);
53 Line_division best_division = ideal_line_division;
54 vsize min_sys_count = 1;
55 vsize ideal_sys_count = system_count ();
57 if (!scm_is_integer (forced_page_count))
59 /* find out the ideal number of pages */
60 message (_ ("Finding the ideal number of pages..."));
62 if (systems_per_page () > 0)
63 best = space_systems_with_fixed_number_per_page (0, first_page_num);
65 best = space_systems_on_best_pages (0, first_page_num);
67 page_count = best.systems_per_page_.size ();
68 ideal_sys_count = best.system_count ();
69 min_sys_count = ideal_sys_count - best.systems_per_page_.back ();
71 if (page_count > 1 && best.systems_per_page_[page_count - 2] > 1)
72 min_sys_count -= best.systems_per_page_[page_count - 2];
74 min_sys_count = max (min_sys_count, (vsize)1);
78 /* TODO: the following line will spit out programming errors if the
79 ideal line spacing doesn't fit on PAGE_COUNT pages */
80 /* TODO: the interaction between systems_per_page and page_count needs to
82 best = space_systems_on_n_pages (0, page_count, first_page_num);
83 min_sys_count = page_count;
87 message (_ ("Fitting music on 1 page..."));
88 else if (scm_is_integer (forced_page_count))
89 message (_f ("Fitting music on %d pages...", (int)page_count));
91 message (_f ("Fitting music on %d or %d pages...", (int)page_count-1, (int)page_count));
93 /* try a smaller number of systems than the ideal number for line breaking */
94 Line_division bound = ideal_line_division;
95 for (vsize sys_count = ideal_sys_count; --sys_count >= min_sys_count;)
97 Page_spacing_result best_for_this_sys_count;
98 set_current_breakpoints (0, end, sys_count, Line_division (), bound);
100 if (debug_page_breaking_scoring)
101 message (_f ("trying %d systems", (int)sys_count));
103 for (vsize i = 0; i < current_configuration_count (); i++)
105 Page_spacing_result cur;
107 if (scm_is_integer (forced_page_count))
108 cur = space_systems_on_n_pages (i, page_count, first_page_num);
110 cur = space_systems_on_best_pages (i, first_page_num);
112 if (cur.demerits_ < best_for_this_sys_count.demerits_)
114 best_for_this_sys_count = cur;
115 bound = current_configuration (i);
119 if (debug_page_breaking_scoring)
120 message (_f ("best score for this sys-count: %f", best_for_this_sys_count.demerits_));
122 if (best_for_this_sys_count.demerits_ < best.demerits_)
124 best = best_for_this_sys_count;
125 best_division = bound;
128 /* Check to see if we already have too few systems. There are two ways
129 we check this: if we are trying one less than the ideal number of pages
130 and the pages are stretched on average then we have too
131 few systems. If the spacing is worse than BAD_SPACING_PENALTY, then we
132 have too few systems. In either case, though, we need to continue reducing
133 the number of systems if max-systems-per-page requires it. */
134 if (!(best.system_count_status_ & SYSTEM_COUNT_TOO_MANY))
136 if (best_for_this_sys_count.page_count () < page_count
137 && best_for_this_sys_count.average_force () > 0)
140 if (best_for_this_sys_count.demerits_ >= BAD_SPACING_PENALTY)
145 /* try a larger number of systems than the ideal line breaking number. This
146 is more or less C&P, but the loop bounds make it difficult to try something
147 like do {...} while (flip(&d) != UP). */
148 bound = ideal_line_division;
149 for (vsize sys_count = ideal_sys_count+1; sys_count <= max_sys_count; sys_count++)
151 Real best_demerits_for_this_sys_count = infinity_f;
152 set_current_breakpoints (0, end, sys_count, bound);
154 if (debug_page_breaking_scoring)
155 message (_f ("trying %d systems", (int)sys_count));
157 for (vsize i = 0; i < current_configuration_count (); i++)
159 vsize min_p_count = min_page_count (i, first_page_num);
160 Page_spacing_result cur;
162 if (min_p_count > page_count)
164 else if (scm_is_integer (forced_page_count))
165 cur = space_systems_on_n_pages (i, page_count, first_page_num);
167 cur = space_systems_on_best_pages (i, first_page_num);
169 if (cur.demerits_ < best.demerits_)
172 best_division = current_configuration (i);
175 if (cur.demerits_ < best_demerits_for_this_sys_count)
177 best_demerits_for_this_sys_count = cur.demerits_;
178 bound = current_configuration (i);
182 if (debug_page_breaking_scoring)
183 message (_f ("best score for this sys-count: %f", best_demerits_for_this_sys_count));
185 if (best_demerits_for_this_sys_count >= BAD_SPACING_PENALTY
186 && !(best.system_count_status_ & SYSTEM_COUNT_TOO_FEW))
190 message (_ ("Drawing systems..."));
191 break_into_pieces (0, end, best_division);
192 SCM lines = systems ();
193 return make_pages (best.systems_per_page_, lines);