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