lily/separating-group-spanner.cc

   1 /*
   2   separating-group-spanner.cc --  implement Separating_group_spanner
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1998--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "separating-group-spanner.hh"
  11 #include "separation-item.hh"
  12 #include "paper-column.hh"
  13 #include "paper-def.hh"
  14 #include "dimensions.hh"
  15 #include "group-interface.hh"
  16
  17 void
  18 Separating_group_spanner::find_rods (Item * r, SCM next, Real padding)
  19 {
  20
  21   /*
  22     This is an inner loop: look for the first normal (unbroken) Left
  23     grob.  This looks like an inner loop (ie. quadratic total), but in
  24     most cases, the interesting L will just be the first entry of
  25     NEXT, making it linear in most of the cases.
  26   */
  27   if (Separation_item::width (r).is_empty ())
  28     return;
  29
  30
  31   for (; gh_pair_p (next); next = ly_cdr (next))
  32     {
  33       Item *l = dynamic_cast<Item*> (unsmob_grob (ly_car ( next)));
  34       Item *lb = l->find_prebroken_piece (RIGHT);
  35
  36       if (lb)
  37         {
  38           Interval li (Separation_item::width (lb));
  39           Interval ri (Separation_item::conditional_width (r, lb));
  40           if (!li.is_empty () && !ri.is_empty ())
  41             {
  42               Rod rod;
  43
  44               rod.item_l_drul_[LEFT] = lb;
  45               rod.item_l_drul_[RIGHT] = r;
  46
  47               rod.distance_ = li[RIGHT] - ri[LEFT] + padding;
  48               rod.add_to_cols ();
  49             }
  50         }
  51
  52       Interval li (Separation_item::width (l));
  53       Interval ri (Separation_item::conditional_width (r, l));
  54       if (!li.is_empty () && !ri.is_empty ())
  55         {
  56           Rod rod;
  57
  58           rod.item_l_drul_[LEFT] =l;
  59           rod.item_l_drul_[RIGHT]=r;
  60
  61           rod.distance_ = li[RIGHT] - ri[LEFT] + padding;
  62
  63           rod.add_to_cols ();
  64           break;
  65         }
  66
  67       /*
  68         this grob doesn't cause a constraint. We look further until we
  69         find one that does.
  70       */
  71
  72     }
  73 }
  74
  75 MAKE_SCHEME_CALLBACK (Separating_group_spanner,set_spacing_rods,1);
  76 SCM
  77 Separating_group_spanner::set_spacing_rods (SCM smob)
  78 {
  79   Grob*me = unsmob_grob (smob);
  80
  81   /*
  82     Ugh: padding is added doubly, also for SeparationItem
  83    */
  84   Real padding = robust_scm2double (me->get_property ("padding"), 0.1);
  85
  86   for (SCM s = me->get_property ("elements"); gh_pair_p (s) && gh_pair_p (ly_cdr (s)); s = ly_cdr (s))
  87     {
  88       /*
  89         Order of elements is reversed!
  90        */
  91       SCM elt = ly_car (s);
  92       Item *r = unsmob_item (elt);
  93
  94       if (!r)
  95         continue;
  96
  97       Item *rb
  98         = dynamic_cast<Item*> (r->find_prebroken_piece (LEFT));
  99
 100       find_rods (r, ly_cdr (s), padding);
 101       if (rb)
 102         find_rods (rb, ly_cdr (s), padding);
 103     }
 104
 105   return SCM_UNSPECIFIED ;
 106 }
 107
 108 void
 109 Separating_group_spanner::add_spacing_unit (Grob* me ,Item*i)
 110 {
 111   Pointer_group_interface::add_grob (me, ly_symbol2scm ("elements"), i);
 112   me->add_dependency (i);
 113 }
 114
 115
 116
 117
 118
 119 ADD_INTERFACE (Separating_group_spanner,"separation-spanner-interface",
 120                "A spanner that calculates spacing constraints (\"rods\") "
 121                "using the @code{separation-item-interface} grobs in @code{elements}.",
 122                "elements padding");