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 system_spec_index_;
  45
  46   /* if system_spec_index_ is a score, then we start at the score_brk_'th possible
  47      page-break in the score */
  48   vsize score_break_;
  49
  50   /* if system_spec_index_ is a score, this points to the broken column */
  51   Grob *col_;
  52   bool score_ender_;
  53
  54   Break_position (vsize s=VPOS, vsize brk=VPOS, Grob *g=NULL, bool end=false)
  55   {
  56     system_spec_index_ = s;
  57     score_break_ = brk;
  58     col_ = g;
  59     score_ender_ = end;
  60   }
  61
  62   /*
  63     lexicographic in (system_spec_index_, score_break_)
  64    */
  65   bool operator< (const Break_position &other)
  66   {
  67     return (system_spec_index_ == VPOS && other.system_spec_index_ != VPOS)
  68       || (system_spec_index_ < other.system_spec_index_)
  69       || (system_spec_index_ == other.system_spec_index_ && score_break_ < other.score_break_);
  70   }
  71
  72   bool operator<= (const Break_position &other)
  73   {
  74     return (system_spec_index_ == VPOS)
  75       || (system_spec_index_ < other.system_spec_index_ && other.system_spec_index_ != VPOS)
  76       || (system_spec_index_ == other.system_spec_index_ && score_break_ <= other.score_break_);
  77   }
  78 };
  79
  80 class Page_breaking
  81 {
  82 public:
  83   typedef bool (*Break_predicate) (Grob *);
  84   typedef vector<vsize> Line_division;
  85
  86   /*
  87     TODO: naming.
  88
  89     determine the page breaking, and break scores into lines
  90     appropriately.
  91    */
  92   virtual SCM solve () = 0;
  93
  94   Page_breaking (Paper_book *pb, Break_predicate);
  95   virtual ~Page_breaking ();
  96
  97   bool ragged () const;
  98   bool ragged_last () const;
  99   bool is_last () const;
 100   Real page_height (int page_number, bool last) const;
 101
 102 protected:
 103   Paper_book *book_;
 104
 105   vsize next_system (Break_position const &break_pos) const;
 106
 107   SCM make_pages (vector<vsize> lines_per_page, SCM lines);
 108
 109   vsize min_system_count (vsize start, vsize end);
 110   vsize max_system_count (vsize start, vsize end);
 111
 112
 113   void break_into_pieces (vsize start, vsize end, Line_division const &div);
 114   SCM systems ();
 115
 116   void set_current_breakpoints (vsize start,
 117                                 vsize end,
 118                                 vsize system_count,
 119                                 Line_division lower_bound = Line_division (),
 120                                 Line_division upper_bound = Line_division ());
 121   void set_to_ideal_line_configuration (vsize start, vsize end);
 122
 123   vsize current_configuration_count () const;
 124   Line_division current_configuration (vsize configuration_index) const;
 125   Spacing_result space_systems_on_n_pages (vsize configuration_index,
 126                                            vsize n, vsize first_page_num);
 127   Spacing_result space_systems_on_n_or_one_more_pages (vsize configuration_index, vsize n,
 128                                                        vsize first_page_num);
 129   Spacing_result space_systems_on_best_pages (vsize configuration_index,
 130                                               vsize first_page_num);
 131   vsize min_page_count (vsize configuration_index, vsize first_page_num);
 132   bool all_lines_stretched (vsize configuration_index);
 133   Real blank_page_penalty () const;
 134
 135   SCM breakpoint_property (vsize breakpoint, char const *str);
 136
 137   vsize last_break_position () const;
 138 private:
 139   vector<Break_position> breaks_;
 140   vector<Break_position> chunks_;
 141   vector<System_spec> system_specs_;
 142   vector<Constrained_breaking> line_breaking_;
 143   bool ragged_;
 144   bool ragged_last_;
 145
 146   vector<Line_division> current_configurations_;
 147   vector<Break_position> current_chunks_;
 148   vsize current_start_breakpoint_;
 149   vsize current_end_breakpoint_;
 150
 151   void cache_line_details (vsize configuration_index);
 152   void clear_line_details_cache ();
 153   vsize cached_configuration_index_;
 154   vector<Line_details> cached_line_details_;
 155   vector<Line_details> uncompressed_line_details_;
 156
 157   vector<Break_position> chunk_list (vsize start, vsize end);
 158   Line_division system_count_bounds (vector<Break_position> const &chunks, bool min);
 159   void line_breaker_args (vsize i,
 160                           Break_position const &start,
 161                           Break_position const &end,
 162                           vsize *line_breaker_start,
 163                           vsize *line_breaker_end);
 164
 165   void line_divisions_rec (vsize system_count,
 166                            Line_division const &min,
 167                            Line_division const &max,
 168                            Line_division *cur);
 169
 170   vector<Line_details> line_details (vsize start, vsize end, Line_division const &div);
 171   Spacing_result space_systems_on_1_page (vector<Line_details> const &lines, Real page_height, bool ragged);
 172   Spacing_result space_systems_on_2_pages (vsize configuration_index, vsize first_page_num);
 173   Spacing_result finalize_spacing_result (vsize configuration_index, Spacing_result);
 174   void create_system_list ();
 175   void find_chunks_and_breaks (Break_predicate);
 176 };
 177 #endif /* PAGE_BREAKING_HH */