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--2009 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   bool ends_score () const;
 104   int systems_per_page () const;
 105   int max_systems_per_page () const;
 106   int min_systems_per_page () const;
 107   Real page_height (int page_number, bool last) const;
 108   vsize system_count () const;
 109   Real line_count_penalty (int line_count) const;
 110   int line_count_status (int line_count) const;
 111   bool too_many_lines (int line_count) const;
 112   bool too_few_lines (int line_count) const;
 113   Real min_whitespace_at_top_of_page (Line_details const&) const;
 114   Real min_whitespace_at_bottom_of_page (Line_details const&) const;
 115
 116 protected:
 117   Paper_book *book_;
 118
 119   vsize next_system (Break_position const &break_pos) const;
 120
 121   SCM make_pages (vector<vsize> lines_per_page, SCM lines);
 122
 123   vsize min_system_count (vsize start, vsize end);
 124   vsize max_system_count (vsize start, vsize end);
 125
 126
 127   void break_into_pieces (vsize start, vsize end, Line_division const &div);
 128   SCM systems ();
 129
 130   void set_current_breakpoints (vsize start,
 131                                 vsize end,
 132                                 vsize system_count,
 133                                 Line_division lower_bound = Line_division (),
 134                                 Line_division upper_bound = Line_division ());
 135   void set_to_ideal_line_configuration (vsize start, vsize end);
 136
 137   vsize current_configuration_count () const;
 138   Line_division current_configuration (vsize configuration_index) const;
 139   Page_spacing_result space_systems_on_n_pages (vsize configuration_index,
 140                                                 vsize n, vsize first_page_num);
 141   Page_spacing_result space_systems_on_n_or_one_more_pages (vsize configuration_index, vsize n,
 142                                                             vsize first_page_num);
 143   Page_spacing_result space_systems_on_best_pages (vsize configuration_index,
 144                                                    vsize first_page_num);
 145   Page_spacing_result space_systems_with_fixed_number_per_page (vsize configuration_index,
 146                                                                 vsize first_page_num);
 147   Page_spacing_result pack_systems_on_least_pages (vsize configuration_index,
 148                                                    vsize first_page_num);
 149   vsize min_page_count (vsize configuration_index, vsize first_page_num);
 150   bool all_lines_stretched (vsize configuration_index);
 151   Real blank_page_penalty () const;
 152
 153   SCM breakpoint_property (vsize breakpoint, char const *str);
 154
 155   vsize last_break_position () const;
 156 private:
 157   vector<Break_position> breaks_;
 158   vector<Break_position> chunks_;
 159   vector<System_spec> system_specs_;
 160   vector<Constrained_breaking> line_breaking_;
 161   bool ragged_;
 162   bool ragged_last_;
 163   int systems_per_page_;
 164   int max_systems_per_page_;
 165   int min_systems_per_page_;
 166   vsize system_count_;
 167
 168   vector<Line_division> current_configurations_;
 169   vector<Break_position> current_chunks_;
 170   vsize current_start_breakpoint_;
 171   vsize current_end_breakpoint_;
 172
 173   void cache_line_details (vsize configuration_index);
 174   void clear_line_details_cache ();
 175   vsize cached_configuration_index_;
 176   vector<Line_details> cached_line_details_;
 177   vector<Line_details> uncompressed_line_details_;
 178
 179   vector<Break_position> chunk_list (vsize start, vsize end);
 180   Line_division system_count_bounds (vector<Break_position> const &chunks, bool min);
 181   void line_breaker_args (vsize i,
 182                           Break_position const &start,
 183                           Break_position const &end,
 184                           vsize *line_breaker_start,
 185                           vsize *line_breaker_end);
 186
 187   void line_divisions_rec (vsize system_count,
 188                            Line_division const &min,
 189                            Line_division const &max,
 190                            Line_division *cur);
 191
 192   vector<Line_details> line_details (vsize start, vsize end, Line_division const &div);
 193   Page_spacing_result space_systems_on_1_page (vector<Line_details> const &lines, Real page_height, bool ragged);
 194   Page_spacing_result space_systems_on_2_pages (vsize configuration_index, vsize first_page_num);
 195   Page_spacing_result finalize_spacing_result (vsize configuration_index, Page_spacing_result);
 196   void create_system_list ();
 197   void find_chunks_and_breaks (Break_predicate);
 198   SCM make_page (int page_num, bool last) const;
 199   SCM get_page_configuration (SCM systems, int page_num, bool ragged, bool last);
 200   SCM draw_page (SCM systems, SCM config, int page_num, bool last);
 201 };
 202 #endif /* PAGE_BREAKING_HH */