lily/include/page-spacing.hh

   1 /*
   2   page-spacing.hh -- routines for spacing systems
   3   vertically across pages
   4
   5   source file of the GNU LilyPond music typesetter
   6
   7   (c) 2006 Joe Neeman <joeneeman@gmail.com>
   8 */
   9
  10 #ifndef PAGE_SPACING_HH
  11 #define PAGE_SPACING_HH
  12
  13 #include "constrained-breaking.hh"
  14
  15 struct Spacing_result {
  16   vector<vsize> systems_per_page_;
  17   vector<Real> force_;
  18   Real penalty_;
  19   Real demerits_;
  20
  21   Spacing_result ()
  22   {
  23     penalty_ = 0;
  24     demerits_ = infinity_f;
  25   }
  26 };
  27
  28 /* for page_count > 2, we use a dynamic algorithm similar to
  29    constrained-breaking -- we have a class that stores the intermediate
  30    calculations so they can be reused for querying different page counts.
  31 */
  32
  33 class Page_spacer
  34 {
  35 public:
  36   Page_spacer (vector<Line_details> const &lines, Real page_height, bool ragged, bool ragged_last);
  37   Spacing_result solve (vsize page_count);
  38
  39 private:
  40   struct Page_spacing_node
  41   {
  42     Page_spacing_node ()
  43     {
  44       demerits_ = infinity_f;
  45       force_ = infinity_f;
  46       penalty_ = infinity_f;
  47       prev_ = VPOS;
  48     }
  49
  50     Real demerits_;
  51     Real force_;
  52     Real penalty_;
  53     vsize prev_;
  54   };
  55
  56   Real page_height_;
  57   vector<Line_details> lines_;
  58   Matrix<Page_spacing_node> state_;
  59   vsize max_page_count_;
  60
  61   bool ragged_;
  62   bool ragged_last_;
  63
  64   void resize (vsize page_count);
  65   bool calc_subproblem (vsize page, vsize lines);
  66 };
  67
  68 Spacing_result
  69 space_systems_on_min_pages (vector<Line_details> const&,
  70                             Real page_height,
  71                             Real odd_pages_penalty,
  72                             bool ragged,
  73                             bool ragged_last);
  74 Spacing_result
  75 space_systems_on_best_pages (vector<Line_details> const&,
  76                              Real page_height,
  77                              Real odd_pages_penalty,
  78                              bool ragged,
  79                              bool ragged_last);
  80
  81 #endif /* PAGE_SPACING_HH */