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   vsize sys_; /* our index in the all_ list */
  45   vsize score_break_; /* if sys_ is a score, then we start at the score_brk_'th
  46                          possible page-break in the score */
  47   Grob *col_;  /* if sys_ is a score, this points to the broken column */
  48   bool score_ender_;
  49
  50   Break_position (vsize s=VPOS, vsize brk=VPOS, Grob *g=NULL, bool end=false)
  51   {
  52     sys_ = s;
  53     score_break_ = brk;
  54     col_ = g;
  55     score_ender_ = end;
  56   }
  57
  58   bool operator< (const Break_position &other)
  59   {
  60     return (sys_ == VPOS && other.sys_ != VPOS)
  61       || (sys_ < other.sys_)
  62       || (sys_ == other.sys_ && score_break_ < other.score_break_);
  63   }
  64
  65   bool operator<= (const Break_position &other)
  66   {
  67     return (sys_ == VPOS)
  68       || (sys_ < other.sys_ && other.sys_ != VPOS)
  69       || (sys_ == other.sys_ && score_break_ <= other.score_break_);
  70   }
  71 };
  72
  73 class Page_breaking
  74 {
  75 public:
  76   typedef bool (*Break_predicate) (Grob *);
  77   typedef vector<vsize> Line_division;
  78
  79   /*
  80     TODO: naming.
  81
  82     determine the page breaking, and break scores into lines
  83     appropriately.
  84    */
  85   virtual SCM solve () = 0;
  86
  87   Page_breaking (Paper_book *pb, Break_predicate);
  88   virtual ~Page_breaking ();
  89
  90   bool ragged () const;
  91   bool ragged_last () const;
  92   bool last () const;
  93   Real page_height (int page_number, bool last) const;
  94
  95 protected:
  96   Paper_book *book_;
  97
  98   vsize next_system (Break_position const &break_pos) const;
  99
 100   SCM make_pages (vector<vsize> lines_per_page, SCM lines);
 101
 102   vsize min_system_count (vsize start, vsize end);
 103   vsize max_system_count (vsize start, vsize end);
 104
 105
 106   void break_into_pieces (vsize start, vsize end, Line_division const &div);
 107   SCM systems ();
 108
 109   void set_current_breakpoints (vsize start,
 110                                 vsize end,
 111                                 vsize system_count,
 112                                 Line_division lower_bound = Line_division (),
 113                                 Line_division upper_bound = Line_division ());
 114   void set_to_ideal_line_configuration (vsize start, vsize end);
 115
 116   vsize current_configuration_count () const;
 117   Line_division current_configuration (vsize configuration_index) const;
 118   Spacing_result space_systems_on_n_pages (vsize configuration_index,
 119                                            vsize n, vsize first_page_num);
 120   Spacing_result space_systems_on_n_or_one_more_pages (vsize configuration_index, vsize n,
 121                                                        vsize first_page_num);
 122   Spacing_result space_systems_on_best_pages (vsize configuration_index,
 123                                               vsize first_page_num);
 124   vsize min_page_count (vsize configuration_index, vsize first_page_num);
 125   bool all_lines_stretched (vsize configuration_index);
 126   Real blank_page_penalty () const;
 127
 128   SCM breakpoint_property (vsize breakpoint, char const *str);
 129   vector<Break_position> breaks_;
 130
 131 private:
 132   vector<Break_position> chunks_;
 133   vector<System_spec> all_;
 134   vector<Constrained_breaking> line_breaking_;
 135   bool ragged_;
 136   bool ragged_last_;
 137
 138   vector<Line_division> current_configurations_;
 139   vector<Break_position> current_chunks_;
 140   vsize current_start_breakpoint_;
 141   vsize current_end_breakpoint_;
 142
 143   void cache_line_details (vsize configuration_index);
 144   void clear_line_details_cache ();
 145   vsize cached_configuration_index_;
 146   vector<Line_details> cached_line_details_;
 147   vector<Line_details> uncompressed_line_details_;
 148
 149   vector<Break_position> chunk_list (vsize start, vsize end);
 150   Line_division system_count_bounds (vector<Break_position> const &chunks, bool min);
 151   void line_breaker_args (vsize i,
 152                           Break_position const &start,
 153                           Break_position const &end,
 154                           vsize *line_breaker_start,
 155                           vsize *line_breaker_end);
 156
 157   void line_divisions_rec (vsize system_count,
 158                            Line_division const &min,
 159                            Line_division const &max,
 160                            Line_division *cur);
 161
 162   vector<Line_details> line_details (vsize start, vsize end, Line_division const &div);
 163   Spacing_result space_systems_on_1_page (vector<Line_details> const &lines, Real page_height, bool ragged);
 164   Spacing_result space_systems_on_2_pages (vsize configuration_index, vsize first_page_num);
 165   Spacing_result finalize_spacing_result (vsize configuration_index, Spacing_result);
 166   void create_system_list ();
 167   void find_chunks_and_breaks (Break_predicate);
 168 };
 169 #endif /* PAGE_BREAKING_HH */