lily/tie-column.cc

   1 /*
   2   tie-column.cc -- implement Tie_column
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "tie-column.hh"
  10 #include "paper-column.hh"
  11 #include "spanner.hh"
  12 #include "group-interface.hh"
  13 #include "tie.hh"
  14 #include "directional-element-interface.hh"
  15 #include "rhythmic-head.hh"
  16
  17 /*
  18   tie dir depends on what Tie_column does.
  19 */
  20 /*
  21   TODO: this doesn't follow standard pattern. Regularize.
  22 */
  23 void
  24 Tie_column::add_tie (Grob *me, Grob *tie)
  25 {
  26   if (tie->get_parent (Y_AXIS)
  27       && Tie_column::has_interface (tie->get_parent (Y_AXIS)))
  28     return;
  29
  30   if (!Pointer_group_interface::count (me, ly_symbol2scm ("ties")))
  31     {
  32       dynamic_cast<Spanner *> (me)->set_bound (LEFT, Tie::head (tie, LEFT));
  33       dynamic_cast<Spanner *> (me)->set_bound (RIGHT, Tie::head (tie, RIGHT));
  34     }
  35
  36   tie->set_parent (me, Y_AXIS);
  37   Pointer_group_interface::add_grob (me, ly_symbol2scm ("ties"), tie);
  38   tie->add_dependency (me);
  39 }
  40
  41 void
  42 Tie_column::set_directions (Grob *me)
  43 {
  44   werner_directions (me);
  45 }
  46
  47 int
  48 tie_compare (Grob *const &s1,
  49              Grob *const &s2)
  50 {
  51   return sign (Tie::get_position (s1) - Tie::get_position (s2));
  52 }
  53
  54 /*
  55   Werner:
  56
  57   . The algorithm to choose the direction of the ties doesn't work
  58   properly.  I suggest the following for applying ties sequentially
  59   from top to bottom:
  60
  61   + The topmost tie is always `up'.
  62
  63   + If there is a vertical gap to the last note above larger than
  64   or equal to a fifth (or sixth?), the tie is `up', otherwise it
  65   is `down'.
  66
  67   + The bottommost tie is always `down'.
  68 */
  69 void
  70 Tie_column::werner_directions (Grob *me)
  71 {
  72   Link_array<Grob> ties
  73     = extract_grob_array (me, ly_symbol2scm ("ties"));
  74
  75   if (!ties.size ())
  76     return;
  77
  78   ties.sort (tie_compare);
  79
  80   Direction d = get_grob_direction (me);
  81   if (d)
  82     {
  83       for (int i = ties.size (); i--;)
  84         {
  85           Grob *t = ties[i];
  86           if (!get_grob_direction (t))
  87             set_grob_direction (t, d);
  88         }
  89       return;
  90     }
  91
  92   if (ties.size () == 1)
  93     {
  94       Grob *t = ties[0];
  95       if (t->is_live ()
  96           && !get_grob_direction (t))
  97         set_grob_direction (t, Tie::get_default_dir (t));
  98       return;
  99     }
 100
 101   Real last_down_pos = 10000;
 102   if (!get_grob_direction (ties[0]))
 103     set_grob_direction (ties[0], DOWN);
 104
 105   /*
 106     Go downward.
 107   */
 108   Grob *last_tie = 0;
 109   for (int i = ties.size (); i--;)
 110     {
 111       Grob *t = ties[i];
 112
 113       Direction d = get_grob_direction (t);
 114       Real p = Tie::get_position (t);
 115       if (!d)
 116         {
 117           if (last_tie
 118               && Tie::get_column_rank (t, LEFT)
 119               < Tie::get_column_rank (last_tie, LEFT))
 120             {
 121               d = DOWN;
 122             }
 123           else if (last_down_pos - p > 5)
 124             {
 125               d = UP;
 126             }
 127           else
 128             {
 129               d = DOWN;
 130             }
 131
 132           set_grob_direction (t, d);
 133         }
 134
 135       if (d == DOWN)
 136         last_down_pos = p;
 137
 138       last_tie = t;
 139     }
 140
 141   return;
 142 }
 143
 144 MAKE_SCHEME_CALLBACK (Tie_column, after_line_breaking, 1);
 145 SCM
 146 Tie_column::after_line_breaking (SCM smob)
 147 {
 148   werner_directions (unsmob_grob (smob));
 149   return SCM_UNSPECIFIED;
 150 }
 151
 152 /*
 153   Extend the spanner over its Tie constituents.
 154 */
 155 MAKE_SCHEME_CALLBACK (Tie_column, before_line_breaking, 1);
 156 SCM
 157 Tie_column::before_line_breaking (SCM smob)
 158 {
 159   Spanner *me = dynamic_cast<Spanner *> (unsmob_grob (smob));
 160   for (SCM s = me->get_property ("ties"); scm_is_pair (s); s = scm_cdr (s))
 161     {
 162       Spanner *tie = dynamic_cast<Spanner *> (unsmob_grob (scm_car (s)));
 163       Direction dir = LEFT;
 164       do
 165         {
 166           if (dir * Paper_column::get_rank (tie->get_bound (dir)->get_column ())
 167               > dir * Paper_column::get_rank (me->get_bound (dir)->get_column ()))
 168             {
 169               me->set_bound (dir, Tie::head (tie, dir));
 170             }
 171         }
 172       while (flip (&dir) != LEFT);
 173     }
 174   return SCM_UNSPECIFIED;
 175 }
 176
 177 ADD_INTERFACE (Tie_column, "tie-column-interface",
 178                "Object that sets directions of multiple ties in a tied chord",
 179                "direction");
 180