lily/include/page-breaking.hh

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2006--2009 Joe Neeman <joeneeman@gmail.com>
   5
   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.
  10
  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.
  15
  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/>.
  18 */
  19
  20 #ifndef PAGE_BREAKING_HH
  21 #define PAGE_BREAKING_HH
  22
  23 #include "constrained-breaking.hh"
  24 #include "page-spacing.hh"
  25
  26 /* Either a paper-score, markup or header.
  27  */
  28 struct System_spec
  29 {
  30   System_spec (Paper_score *ps)
  31   {
  32     pscore_ = ps;
  33     prob_ = NULL;
  34   }
  35
  36   System_spec (Prob *pb)
  37   {
  38     prob_ = pb;
  39     pscore_ = NULL;
  40   }
  41
  42   System_spec ()
  43   {
  44     pscore_ = NULL;
  45     prob_ = NULL;
  46   }
  47
  48   Paper_score *pscore_;
  49   Prob *prob_;
  50 };
  51
  52 struct Break_position
  53 {
  54   /*
  55     index in system_spec_index_, if VPOS start of book.
  56    */
  57   vsize system_spec_index_;
  58
  59   /* if system_spec_index_ is a score, then we start at the score_brk_'th possible
  60      page-break in the score */
  61   vsize score_break_;
  62
  63   /* if system_spec_index_ is a score, this points to the broken column */
  64   Grob *col_;
  65   bool score_ender_;
  66
  67   /* if non-zero, this is the (fixed, uncompressed) number of lines between
  68      this Break_position and the previous. */
  69   int forced_line_count_;
  70
  71   Break_position (vsize s=VPOS, vsize brk=VPOS, Grob *g=NULL, bool end=false)
  72   {
  73     system_spec_index_ = s;
  74     score_break_ = brk;
  75     col_ = g;
  76     score_ender_ = end;
  77     forced_line_count_ = 0;
  78   }
  79
  80   /*
  81     lexicographic in (system_spec_index_, score_break_)
  82    */
  83   bool operator< (const Break_position &other)
  84   {
  85     return (system_spec_index_ == VPOS && other.system_spec_index_ != VPOS)
  86       || (system_spec_index_ < other.system_spec_index_)
  87       || (system_spec_index_ == other.system_spec_index_ && score_break_ < other.score_break_);
  88   }
  89
  90   bool operator<= (const Break_position &other)
  91   {
  92     return (system_spec_index_ == VPOS)
  93       || (system_spec_index_ < other.system_spec_index_ && other.system_spec_index_ != VPOS)
  94       || (system_spec_index_ == other.system_spec_index_ && score_break_ <= other.score_break_);
  95   }
  96 };
  97
  98 class Page_breaking
  99 {
 100 public:
 101   typedef bool (*Break_predicate) (Grob *);
 102   typedef vector<vsize> Line_division;
 103
 104   /*
 105     TODO: naming.
 106
 107     determine the page breaking, and break scores into lines
 108     appropriately.
 109    */
 110   virtual SCM solve () = 0;
 111
 112   Page_breaking (Paper_book *pb, Break_predicate);
 113   virtual ~Page_breaking ();
 114
 115   bool ragged () const;
 116   bool ragged_last () const;
 117   bool is_last () const;
 118   bool ends_score () const;
 119   int systems_per_page () const;
 120   int max_systems_per_page () const;
 121   int min_systems_per_page () const;
 122   Real page_height (int page_number, bool last) const;
 123   vsize system_count () const;
 124   Real line_count_penalty (int line_count) const;
 125   int line_count_status (int line_count) const;
 126   bool too_many_lines (int line_count) const;
 127   bool too_few_lines (int line_count) const;
 128   Real min_whitespace_at_top_of_page (Line_details const&) const;
 129   Real min_whitespace_at_bottom_of_page (Line_details const&) const;
 130
 131 protected:
 132   Paper_book *book_;
 133
 134   vsize next_system (Break_position const &break_pos) const;
 135
 136   SCM make_pages (vector<vsize> lines_per_page, SCM lines);
 137
 138   vsize min_system_count (vsize start, vsize end);
 139   vsize max_system_count (vsize start, vsize end);
 140
 141
 142   void break_into_pieces (vsize start, vsize end, Line_division const &div);
 143   SCM systems ();
 144
 145   void set_current_breakpoints (vsize start,
 146                                 vsize end,
 147                                 vsize system_count,
 148                                 Line_division lower_bound = Line_division (),
 149                                 Line_division upper_bound = Line_division ());
 150   void set_to_ideal_line_configuration (vsize start, vsize end);
 151
 152   vsize current_configuration_count () const;
 153   Line_division current_configuration (vsize configuration_index) const;
 154   Page_spacing_result space_systems_on_n_pages (vsize configuration_index,
 155                                                 vsize n, vsize first_page_num);
 156   Page_spacing_result space_systems_on_n_or_one_more_pages (vsize configuration_index, vsize n,
 157                                                             vsize first_page_num,
 158                                                             Real penalty_for_fewer_pages);
 159   Page_spacing_result space_systems_on_best_pages (vsize configuration_index,
 160                                                    vsize first_page_num);
 161   Page_spacing_result space_systems_with_fixed_number_per_page (vsize configuration_index,
 162                                                                 vsize first_page_num);
 163   Page_spacing_result pack_systems_on_least_pages (vsize configuration_index,
 164                                                    vsize first_page_num);
 165   vsize min_page_count (vsize configuration_index, vsize first_page_num);
 166   bool all_lines_stretched (vsize configuration_index);
 167   Real blank_page_penalty () const;
 168
 169   SCM breakpoint_property (vsize breakpoint, char const *str);
 170
 171   vsize last_break_position () const;
 172 private:
 173   vector<Break_position> breaks_;
 174   vector<Break_position> chunks_;
 175   vector<System_spec> system_specs_;
 176   vector<Constrained_breaking> line_breaking_;
 177   bool ragged_;
 178   bool ragged_last_;
 179   int systems_per_page_;
 180   int max_systems_per_page_;
 181   int min_systems_per_page_;
 182   vsize system_count_;
 183
 184   vector<Line_division> current_configurations_;
 185   vector<Break_position> current_chunks_;
 186   vsize current_start_breakpoint_;
 187   vsize current_end_breakpoint_;
 188
 189   void cache_line_details (vsize configuration_index);
 190   void clear_line_details_cache ();
 191   vsize cached_configuration_index_;
 192   vector<Line_details> cached_line_details_;
 193   vector<Line_details> uncompressed_line_details_;
 194
 195   vector<Break_position> chunk_list (vsize start, vsize end);
 196   Line_division system_count_bounds (vector<Break_position> const &chunks, bool min);
 197   void line_breaker_args (vsize i,
 198                           Break_position const &start,
 199                           Break_position const &end,
 200                           vsize *line_breaker_start,
 201                           vsize *line_breaker_end);
 202
 203   void line_divisions_rec (vsize system_count,
 204                            Line_division const &min,
 205                            Line_division const &max,
 206                            Line_division *cur);
 207
 208   vector<Line_details> line_details (vsize start, vsize end, Line_division const &div);
 209   Page_spacing_result space_systems_on_1_page (vector<Line_details> const &lines, Real page_height, bool ragged);
 210   Page_spacing_result space_systems_on_2_pages (vsize configuration_index, vsize first_page_num);
 211   Page_spacing_result finalize_spacing_result (vsize configuration_index, Page_spacing_result);
 212   void create_system_list ();
 213   void find_chunks_and_breaks (Break_predicate);
 214   SCM make_page (int page_num, bool last) const;
 215   SCM get_page_configuration (SCM systems, int page_num, bool ragged, bool last);
 216   SCM draw_page (SCM systems, SCM config, int page_num, bool last);
 217 };
 218 #endif /* PAGE_BREAKING_HH */