lily/include/page-breaking.hh

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2006--2010 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 into system_specs_, if this is VPOS, the Break_position represents the
  56     start of the book.
  57    */
  58   vsize system_spec_index_;
  59
  60   /* if system_spec_index_ indexes a score, then we start at the score_brk_'th
  61      possible page-break in the score */
  62   vsize score_break_;
  63
  64   /* if system_spec_index_ indexes a score, this points to the broken column */
  65   Grob *col_;
  66   bool score_ender_;
  67
  68   /* if non-zero, this is the (fixed, uncompressed) number of lines between
  69      this Break_position and the previous. */
  70   int forced_line_count_;
  71
  72   Break_position (vsize s=VPOS, vsize brk=VPOS, Grob *g=NULL, bool end=false)
  73   {
  74     system_spec_index_ = s;
  75     score_break_ = brk;
  76     col_ = g;
  77     score_ender_ = end;
  78     forced_line_count_ = 0;
  79   }
  80
  81   /*
  82     lexicographic in (system_spec_index_, score_break_)
  83    */
  84   bool operator< (const Break_position &other)
  85   {
  86     return (system_spec_index_ == VPOS && other.system_spec_index_ != VPOS)
  87       || (system_spec_index_ < other.system_spec_index_)
  88       || (system_spec_index_ == other.system_spec_index_ && score_break_ < other.score_break_);
  89   }
  90
  91   bool operator<= (const Break_position &other)
  92   {
  93     return (system_spec_index_ == VPOS)
  94       || (system_spec_index_ < other.system_spec_index_ && other.system_spec_index_ != VPOS)
  95       || (system_spec_index_ == other.system_spec_index_ && score_break_ <= other.score_break_);
  96   }
  97 };
  98
  99 class Page_breaking
 100 {
 101 public:
 102   typedef bool (*Break_predicate) (Grob *);
 103   typedef bool (*Prob_break_predicate) (Prob *);
 104   typedef vector<vsize> Line_division;
 105
 106   /*
 107     TODO: naming.
 108
 109     determine the page breaking, and break scores into lines
 110     appropriately.
 111    */
 112   virtual SCM solve () = 0;
 113
 114   Page_breaking (Paper_book *pb, Break_predicate, Prob_break_predicate);
 115   virtual ~Page_breaking ();
 116
 117   bool ragged () const;
 118   bool ragged_last () const;
 119   bool is_last () const;
 120   bool ends_score () const;
 121   int systems_per_page () const;
 122   int max_systems_per_page () const;
 123   int min_systems_per_page () const;
 124   Real page_height (int page_number, bool last) const;
 125   Real paper_height () const;
 126   vsize system_count () const;
 127   Real line_count_penalty (int line_count) const;
 128   int line_count_status (int line_count) const;
 129   bool too_many_lines (int line_count) const;
 130   bool too_few_lines (int line_count) const;
 131   Real min_whitespace_at_top_of_page (Line_details const&) const;
 132   Real min_whitespace_at_bottom_of_page (Line_details const&) const;
 133   int orphan_penalty () const;
 134
 135 protected:
 136   Paper_book *book_;
 137
 138   vsize next_system (Break_position const &break_pos) const;
 139
 140   SCM make_pages (vector<vsize> lines_per_page, SCM lines);
 141
 142   vsize min_system_count (vsize start, vsize end);
 143   vsize max_system_count (vsize start, vsize end);
 144
 145
 146   void break_into_pieces (vsize start, vsize end, Line_division const &div);
 147   SCM systems ();
 148
 149   void set_current_breakpoints (vsize start,
 150                                 vsize end,
 151                                 vsize system_count,
 152                                 Line_division lower_bound = Line_division (),
 153                                 Line_division upper_bound = Line_division ());
 154   void set_to_ideal_line_configuration (vsize start, vsize end);
 155
 156   vsize current_configuration_count () const;
 157   Line_division current_configuration (vsize configuration_index) const;
 158   Page_spacing_result space_systems_on_n_pages (vsize configuration_index,
 159                                                 vsize n, vsize first_page_num);
 160   Page_spacing_result space_systems_on_n_or_one_more_pages (vsize configuration_index, vsize n,
 161                                                             vsize first_page_num,
 162                                                             Real penalty_for_fewer_pages);
 163   Page_spacing_result space_systems_on_best_pages (vsize configuration_index,
 164                                                    vsize first_page_num);
 165   Page_spacing_result space_systems_with_fixed_number_per_page (vsize configuration_index,
 166                                                                 vsize first_page_num);
 167   Page_spacing_result pack_systems_on_least_pages (vsize configuration_index,
 168                                                    vsize first_page_num);
 169   vsize min_page_count (vsize configuration_index, vsize first_page_num);
 170   bool all_lines_stretched (vsize configuration_index);
 171   Real blank_page_penalty () const;
 172
 173   SCM breakpoint_property (vsize breakpoint, char const *str);
 174
 175   vsize last_break_position () const;
 176 private:
 177   vector<Break_position> breaks_;
 178   vector<Break_position> chunks_;
 179   vector<System_spec> system_specs_;
 180   vector<Constrained_breaking> line_breaking_;
 181   bool ragged_;
 182   bool ragged_last_;
 183   int systems_per_page_;
 184   int max_systems_per_page_;
 185   int min_systems_per_page_;
 186   vsize system_count_;
 187   int orphan_penalty_;
 188
 189   vector<Line_division> current_configurations_;
 190   vector<Break_position> current_chunks_;
 191   vsize current_start_breakpoint_;
 192   vsize current_end_breakpoint_;
 193
 194   void cache_line_details (vsize configuration_index);
 195   void compute_line_heights ();
 196   void clear_line_details_cache ();
 197   vsize cached_configuration_index_;
 198   vector<Line_details> cached_line_details_;
 199   vector<Line_details> uncompressed_line_details_;
 200
 201   Real paper_height_;
 202   mutable vector<Real> page_height_cache_;
 203   mutable vector<Real> last_page_height_cache_;
 204
 205   vector<Break_position> chunk_list (vsize start, vsize end);
 206   Line_division system_count_bounds (vector<Break_position> const &chunks, bool min);
 207   void line_breaker_args (vsize i,
 208                           Break_position const &start,
 209                           Break_position const &end,
 210                           vsize *line_breaker_start,
 211                           vsize *line_breaker_end);
 212
 213   void line_divisions_rec (vsize system_count,
 214                            Line_division const &min,
 215                            Line_division const &max,
 216                            Line_division *cur);
 217
 218   vector<Line_details> line_details (vsize start, vsize end, Line_division const &div);
 219   Page_spacing_result space_systems_on_1_page (vector<Line_details> const &lines, Real page_height, bool ragged);
 220   Page_spacing_result space_systems_on_2_pages (vsize configuration_index, vsize first_page_num);
 221   Page_spacing_result finalize_spacing_result (vsize configuration_index, Page_spacing_result);
 222   void create_system_list ();
 223   void find_chunks_and_breaks (Break_predicate, Prob_break_predicate);
 224   SCM make_page (int page_num, bool last) const;
 225   SCM get_page_configuration (SCM systems, int page_num, bool ragged, bool last);
 226   SCM draw_page (SCM systems, SCM config, int page_num, bool last);
 227 };
 228 #endif /* PAGE_BREAKING_HH */