lily/include/page-breaking.hh

   1 /*
   2   page-breaking.hh -- declare a superclass and utility
   3   functions for several different page-breaking algorithms
   4
   5   source file of the GNU LilyPond music typesetter
   6
   7   (c) 2006--2007 Joe Neeman <joeneeman@gmail.com>
   8 */
   9
  10 #ifndef PAGE_BREAKING_HH
  11 #define PAGE_BREAKING_HH
  12
  13 #include "constrained-breaking.hh"
  14 #include "page-spacing.hh"
  15
  16 /* Either a paper-score, markup or header.
  17  */
  18 struct System_spec
  19 {
  20   System_spec (Paper_score *ps)
  21   {
  22     pscore_ = ps;
  23     prob_ = NULL;
  24   }
  25
  26   System_spec (Prob *pb)
  27   {
  28     prob_ = pb;
  29     pscore_ = NULL;
  30   }
  31
  32   System_spec ()
  33   {
  34     pscore_ = NULL;
  35     prob_ = NULL;
  36   }
  37
  38   Paper_score *pscore_;
  39   Prob *prob_;
  40 };
  41
  42 struct Break_position
  43 {
  44   /*
  45     index in system_spec_index_, if VPOS start of book.
  46    */
  47   vsize system_spec_index_;
  48
  49   /* if system_spec_index_ is a score, then we start at the score_brk_'th possible
  50      page-break in the score */
  51   vsize score_break_;
  52
  53   /* if system_spec_index_ is a score, this points to the broken column */
  54   Grob *col_;
  55   bool score_ender_;
  56
  57   Break_position (vsize s=VPOS, vsize brk=VPOS, Grob *g=NULL, bool end=false)
  58   {
  59     system_spec_index_ = s;
  60     score_break_ = brk;
  61     col_ = g;
  62     score_ender_ = end;
  63   }
  64
  65   /*
  66     lexicographic in (system_spec_index_, score_break_)
  67    */
  68   bool operator< (const Break_position &other)
  69   {
  70     return (system_spec_index_ == VPOS && other.system_spec_index_ != VPOS)
  71       || (system_spec_index_ < other.system_spec_index_)
  72       || (system_spec_index_ == other.system_spec_index_ && score_break_ < other.score_break_);
  73   }
  74
  75   bool operator<= (const Break_position &other)
  76   {
  77     return (system_spec_index_ == VPOS)
  78       || (system_spec_index_ < other.system_spec_index_ && other.system_spec_index_ != VPOS)
  79       || (system_spec_index_ == other.system_spec_index_ && score_break_ <= other.score_break_);
  80   }
  81 };
  82
  83 class Page_breaking
  84 {
  85 public:
  86   typedef bool (*Break_predicate) (Grob *);
  87   typedef vector<vsize> Line_division;
  88
  89   /*
  90     TODO: naming.
  91
  92     determine the page breaking, and break scores into lines
  93     appropriately.
  94    */
  95   virtual SCM solve () = 0;
  96
  97   Page_breaking (Paper_book *pb, Break_predicate);
  98   virtual ~Page_breaking ();
  99
 100   bool ragged () const;
 101   bool ragged_last () const;
 102   bool is_last () const;
 103   Real page_height (int page_number, bool last) const;
 104
 105 protected:
 106   Paper_book *book_;
 107
 108   vsize next_system (Break_position const &break_pos) const;
 109
 110   SCM make_pages (vector<vsize> lines_per_page, SCM lines);
 111
 112   vsize min_system_count (vsize start, vsize end);
 113   vsize max_system_count (vsize start, vsize end);
 114
 115
 116   void break_into_pieces (vsize start, vsize end, Line_division const &div);
 117   SCM systems ();
 118
 119   void set_current_breakpoints (vsize start,
 120                                 vsize end,
 121                                 vsize system_count,
 122                                 Line_division lower_bound = Line_division (),
 123                                 Line_division upper_bound = Line_division ());
 124   void set_to_ideal_line_configuration (vsize start, vsize end);
 125
 126   vsize current_configuration_count () const;
 127   Line_division current_configuration (vsize configuration_index) const;
 128   Page_spacing_result space_systems_on_n_pages (vsize configuration_index,
 129                                            vsize n, vsize first_page_num);
 130   Page_spacing_result space_systems_on_n_or_one_more_pages (vsize configuration_index, vsize n,
 131                                                        vsize first_page_num);
 132   Page_spacing_result space_systems_on_best_pages (vsize configuration_index,
 133                                               vsize first_page_num);
 134   Page_spacing_result pack_systems_on_least_pages (vsize configuration_index,
 135                                                    vsize first_page_num);
 136   vsize min_page_count (vsize configuration_index, vsize first_page_num);
 137   bool all_lines_stretched (vsize configuration_index);
 138   Real blank_page_penalty () const;
 139
 140   SCM breakpoint_property (vsize breakpoint, char const *str);
 141
 142   vsize last_break_position () const;
 143 private:
 144   vector<Break_position> breaks_;
 145   vector<Break_position> chunks_;
 146   vector<System_spec> system_specs_;
 147   vector<Constrained_breaking> line_breaking_;
 148   bool ragged_;
 149   bool ragged_last_;
 150
 151   vector<Line_division> current_configurations_;
 152   vector<Break_position> current_chunks_;
 153   vsize current_start_breakpoint_;
 154   vsize current_end_breakpoint_;
 155
 156   void cache_line_details (vsize configuration_index);
 157   void clear_line_details_cache ();
 158   vsize cached_configuration_index_;
 159   vector<Line_details> cached_line_details_;
 160   vector<Line_details> uncompressed_line_details_;
 161
 162   vector<Break_position> chunk_list (vsize start, vsize end);
 163   Line_division system_count_bounds (vector<Break_position> const &chunks, bool min);
 164   void line_breaker_args (vsize i,
 165                           Break_position const &start,
 166                           Break_position const &end,
 167                           vsize *line_breaker_start,
 168                           vsize *line_breaker_end);
 169
 170   void line_divisions_rec (vsize system_count,
 171                            Line_division const &min,
 172                            Line_division const &max,
 173                            Line_division *cur);
 174
 175   vector<Line_details> line_details (vsize start, vsize end, Line_division const &div);
 176   Page_spacing_result space_systems_on_1_page (vector<Line_details> const &lines, Real page_height, bool ragged);
 177   Page_spacing_result space_systems_on_2_pages (vsize configuration_index, vsize first_page_num);
 178   Page_spacing_result finalize_spacing_result (vsize configuration_index, Page_spacing_result);
 179   void create_system_list ();
 180   void find_chunks_and_breaks (Break_predicate);
 181 };
 182 #endif /* PAGE_BREAKING_HH */