lily/spacing-determine-loose-columns.cc

   1 /*
   2   spacing-determine-loose-columns.cc -- implement Spacing_spanner
   3   methods that decide which columns to turn loose.
   4
   5   source file of the GNU LilyPond music typesetter
   6
   7   (c) 2005--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   8 */
   9
  10 #include "staff-spacing.hh"
  11
  12 #include "spacing-options.hh"
  13 #include "system.hh"
  14 #include "paper-column.hh"
  15 #include "column-x-positions.hh"
  16 #include "pointer-group-interface.hh"
  17 #include "spacing-interface.hh"
  18 #include "spacing-spanner.hh"
  19 #include "note-spacing.hh"
  20 #include "moment.hh"
  21 #include "grob-array.hh"
  22 #include "break-align-interface.hh"
  23 #include "warn.hh"
  24
  25 /*
  26   Return whether COL is fixed to its neighbors by some kind of spacing
  27   constraint.
  28
  29
  30   If in doubt, then we're not loose; the spacing engine should space
  31   for it, risking suboptimal spacing.
  32
  33   (Otherwise, we might risk core dumps, and other weird stuff.)
  34 */
  35 static bool
  36 is_loose_column (Grob *l, Grob *col, Grob *r, Spacing_options const *options)
  37 {
  38   if (!to_boolean (col->get_property ("allow-loose-spacing")))
  39     return false;
  40
  41
  42   if ((options->float_nonmusical_columns_
  43        || options->float_grace_columns_)
  44       && Paper_column::when_mom (col).grace_part_)
  45     {
  46       return true;
  47     }
  48
  49
  50   if (Paper_column::is_musical (col))
  51     return false;
  52
  53   /*
  54     If this column doesn't have a proper neighbor, we should really
  55     make it loose, but spacing it correctly is more than we can
  56     currently can handle.
  57
  58     (this happens in the following situation:
  59
  60     |
  61     |    clef G
  62     *
  63
  64     |               |      ||
  65     |               |      ||
  66     O               O       ||
  67
  68
  69     the column containing the clef is really loose, and should be
  70     attached right to the first column, but that is a lot of work for
  71     such a borderline case.)
  72
  73   */
  74
  75   Item *r_neighbor = unsmob_item (col->get_object ("right-neighbor"));
  76   Item *l_neighbor = unsmob_item (col->get_object ("left-neighbor"));
  77
  78   if (!l_neighbor || !r_neighbor)
  79     return false;
  80
  81   /* If a non-empty column (ie. not \bar "") is placed nicely in series with
  82      its neighbor (ie. no funny polyphonic stuff), don't make it loose.
  83   */
  84   if (l == l_neighbor && r == r_neighbor && col->extent (col, X_AXIS).length () > 0)
  85      return false;
  86
  87   /*
  88     Only declare loose if the bounds make a little sense.  This means
  89     some cases (two isolated, consecutive clef changes) won't be
  90     nicely folded, but hey, then don't do that.
  91   */
  92   if (! ((Paper_column::is_musical (l_neighbor) || Paper_column::is_breakable (l_neighbor))
  93          && (Paper_column::is_musical (r_neighbor) || Paper_column::is_breakable (r_neighbor))))
  94     return false;
  95
  96   /*
  97     in any case, we don't want to move bar lines.
  98   */
  99   extract_grob_set (col, "elements", elts);
 100   for (vsize i = elts.size (); i--;)
 101     {
 102       Grob *g = elts[i];
 103       if (g && Break_alignment_interface::has_interface (g))
 104         {
 105           extract_grob_set (g, "elements", gelts);
 106           for (vsize j = gelts.size (); j--;)
 107             {
 108               Grob *h = gelts[j];
 109
 110               if (h && h->get_property ("break-align-symbol") == ly_symbol2scm ("staff-bar"))
 111                 {
 112                   extract_grob_set (h, "elements", helts);
 113                   for (vsize k = helts.size (); k--;)
 114                     if ("" != robust_scm2string (helts[k]->get_property ("glyph-name"), ""))
 115                       return false;
 116                 }
 117             }
 118         }
 119     }
 120
 121   return true;
 122 }
 123
 124 void
 125 Spacing_spanner::set_distances_for_loose_col (Grob *me, Grob *c,
 126                                               Drul_array<Item *> next_door,
 127                                               Spacing_options const *options)
 128 {
 129   Direction d = LEFT;
 130   Drul_array<Real> dists (0, 0);
 131
 132   do
 133     {
 134       Item *lc = dynamic_cast<Item *> ((d == LEFT) ? next_door[LEFT] : c);
 135       Item *rc = dynamic_cast<Item *> (d == LEFT ? c : next_door[RIGHT]);
 136
 137       extract_grob_set (lc, "spacing-wishes", wishes);
 138       for (vsize k = wishes.size (); k--;)
 139         {
 140           Grob *sp = wishes[k];
 141           if (Spacing_interface::left_column (sp) != lc
 142               || Spacing_interface::right_column (sp) != rc)
 143             continue;
 144
 145           if (Note_spacing::has_interface (sp))
 146             {
 147               /*
 148                 The note spacing should be taken from the musical
 149                 columns.
 150               */
 151               Real base = note_spacing (me, lc, rc, options);
 152               Spring spring = Note_spacing::get_spacing (sp, rc, base, options->increment_);
 153
 154               dists[d] = max (dists[d], spring.min_distance ());
 155             }
 156           else if (Staff_spacing::has_interface (sp))
 157             {
 158               Spring spring = Staff_spacing::get_spacing (sp, rc);
 159
 160               dists[d] = max (dists[d], spring.min_distance ());
 161             }
 162           else
 163             programming_error ("Subversive spacing wish");
 164         }
 165     }
 166   while (flip (&d) != LEFT);
 167
 168   Rod r;
 169   r.distance_ = dists[LEFT] + dists[RIGHT];
 170   r.item_drul_ = next_door;
 171
 172   r.add_to_cols ();
 173 }
 174
 175
 176 /*
 177   Remove columns that are not tightly fitting from COLS. In the
 178   removed columns, set 'between-cols to the columns where it is in
 179   between.
 180 */
 181 void
 182 Spacing_spanner::prune_loose_columns (Grob *me,
 183                                       vector<Grob*> *cols,
 184                                       Spacing_options *options)
 185 {
 186   vector<Grob*> newcols;
 187
 188   for (vsize i = 0; i < cols->size (); i++)
 189     {
 190       Grob *c = cols->at (i);
 191
 192       bool loose = (i > 0 && i + 1 < cols->size ())
 193         && is_loose_column (cols->at (i - 1), c, cols->at (i + 1), options);
 194
 195       /* Breakable columns never get pruned; even if they are loose,
 196         their broken pieces are not.  However, we mark them so that
 197         the spacing can take their mid-line looseness into account. */
 198       if (loose && Paper_column::is_breakable (c))
 199         {
 200           loose = false;
 201           c->set_property ("maybe-loose", SCM_BOOL_T);
 202         }
 203
 204       if (loose)
 205         {
 206           Grob *right_neighbor = unsmob_grob (c->get_object ("right-neighbor"));
 207           Grob *left_neighbor = unsmob_grob (c->get_object ("left-neighbor"));
 208
 209           /*
 210             Either object can be non existent, if the score ends
 211             prematurely.
 212           */
 213           if (!right_neighbor || !left_neighbor)
 214             {
 215               c->programming_error ("Cannot determine neighbors for floating column. ");
 216               c->set_object ("between-cols", scm_cons (cols->at (i-1)->self_scm (),
 217                                                        cols->at (i+1)->self_scm ()));
 218             }
 219           else
 220             {
 221               c->set_object ("between-cols", scm_cons (left_neighbor->self_scm (),
 222                                                        right_neighbor->self_scm ()));
 223
 224
 225               /*
 226                 Set distance constraints for loose columns
 227               */
 228               Drul_array<Item *> next_door (dynamic_cast<Item*> (cols->at (i - 1)),
 229                                             dynamic_cast<Item*> (cols->at (i + 1)));
 230
 231               set_distances_for_loose_col (me, c, next_door, options);
 232             }
 233         }
 234
 235       if (!loose)
 236         newcols.push_back (c);
 237     }
 238
 239   *cols = newcols;
 240 }
 241
 242 /*
 243   Set neighboring columns determined by the spacing-wishes grob property.
 244 */
 245 void
 246 Spacing_spanner::set_explicit_neighbor_columns (vector<Grob*> const &cols)
 247 {
 248   for (vsize i = 0; i < cols.size (); i++)
 249     {
 250       extract_grob_set (cols[i], "spacing-wishes", wishes);
 251       for (vsize j = wishes.size (); j--;)
 252         {
 253           Item *wish = dynamic_cast<Item*> (wishes[j]);
 254           Item *left_col = wish->get_column ();
 255           int left_rank = Paper_column::get_rank (left_col);
 256           int min_right_rank = INT_MAX;
 257
 258           extract_grob_set (wish, "right-items", right_items);
 259           for (vsize k = right_items.size (); k--;)
 260             {
 261               Item *right_col = dynamic_cast<Item*> (right_items[k])->get_column ();
 262               int right_rank = Paper_column::get_rank (right_col);
 263
 264               if (right_rank < min_right_rank)
 265                 {
 266                   left_col->set_object ("right-neighbor", right_col->self_scm ());
 267                   min_right_rank = right_rank;
 268                 }
 269
 270               Grob *old_left_neighbor = unsmob_grob (right_col->get_object ("left-neighbor"));
 271               if (!old_left_neighbor || left_rank > Paper_column::get_rank (old_left_neighbor))
 272                 right_col->set_object ("left-neighbor", left_col->self_scm ());
 273             }
 274         }
 275     }
 276 }
 277
 278 /*
 279   Set neighboring columns that have no left/right-neighbor set
 280   yet. Only do breakable non-musical columns, and musical columns.
 281   Why only these? --jneem
 282 */
 283 void
 284 Spacing_spanner::set_implicit_neighbor_columns (vector<Grob*> const &cols)
 285 {
 286   for (vsize i = 0; i < cols.size (); i++)
 287     {
 288       Item *it = dynamic_cast<Item *> (cols[i]);
 289       if (!Paper_column::is_breakable (it) && !Paper_column::is_musical (it))
 290         continue;
 291
 292       if (i && !unsmob_grob (cols[i]->get_object ("left-neighbor")))
 293         cols[i]->set_object ("left-neighbor", cols[i-1]->self_scm ());
 294       if (i + 1 < cols.size () && !unsmob_grob (cols[i]->get_object ("right-neighbor")))
 295         cols[i]->set_object ("right-neighbor", cols[i+1]->self_scm ());
 296     }
 297 }