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--2007 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       || Paper_column::is_breakable (col))
  52     return false;
  53
  54   /*
  55     If this column doesn't have a proper neighbor, we should really
  56     make it loose, but spacing it correctly is more than we can
  57     currently can handle.
  58
  59     (this happens in the following situation:
  60
  61     |
  62     |    clef G
  63     *
  64
  65     |               |      ||
  66     |               |      ||
  67     O               O       ||
  68
  69
  70     the column containing the clef is really loose, and should be
  71     attached right to the first column, but that is a lot of work for
  72     such a borderline case.)
  73
  74   */
  75
  76   extract_grob_set (col, "right-neighbors", rns);
  77   extract_grob_set (col, "left-neighbors", lns);
  78
  79   if (lns.empty () || rns.empty ())
  80     return false;
  81
  82
  83   Item *l_neighbor = dynamic_cast<Item *> (lns[0]);
  84   Item *r_neighbor = dynamic_cast<Item *> (rns[0]);
  85
  86   if (!l_neighbor || !r_neighbor)
  87     return false;
  88
  89   l_neighbor = l_neighbor->get_column ();
  90   r_neighbor = dynamic_cast<Item *> (Spacing_interface::right_column (r_neighbor));
  91
  92   if (l == l_neighbor && r == r_neighbor)
  93     return false;
  94
  95   if (!l_neighbor || !r_neighbor)
  96     return false;
  97
  98   /*
  99     Only declare loose if the bounds make a little sense.  This means
 100     some cases (two isolated, consecutive clef changes) won't be
 101     nicely folded, but hey, then don't do that.
 102   */
 103   if (! ((Paper_column::is_musical (l_neighbor) || Paper_column::is_breakable (l_neighbor))
 104          && (Paper_column::is_musical (r_neighbor) || Paper_column::is_breakable (r_neighbor))))
 105     return false;
 106
 107   /*
 108     in any case, we don't want to move bar lines.
 109   */
 110   extract_grob_set (col, "elements", elts);
 111   for (vsize i = elts.size (); i--;)
 112     {
 113       Grob *g = elts[i];
 114       if (g && Break_alignment_interface::has_interface (g))
 115         {
 116           extract_grob_set (g, "elements", gelts);
 117           for (vsize j = gelts.size (); j--;)
 118             {
 119               Grob *h = gelts[j];
 120
 121               if (h && h->get_property ("break-align-symbol") == ly_symbol2scm ("staff-bar"))
 122                 return false;
 123             }
 124         }
 125     }
 126
 127   return true;
 128 }
 129
 130 void
 131 Spacing_spanner::set_distances_for_loose_col (Grob *me, Grob *c,
 132                                               Drul_array<Item *> next_door,
 133                                               Spacing_options const *options)
 134 {
 135   Direction d = LEFT;
 136   Drul_array<Real> dists (0, 0);
 137
 138   do
 139     {
 140       Item *lc = dynamic_cast<Item *> ((d == LEFT) ? next_door[LEFT] : c);
 141       Item *rc = dynamic_cast<Item *> (d == LEFT ? c : next_door[RIGHT]);
 142
 143       extract_grob_set (lc, "spacing-wishes", wishes);
 144       for (vsize k = wishes.size (); k--;)
 145         {
 146           Grob *sp = wishes[k];
 147           if (Spacing_interface::left_column (sp) != lc
 148               || Spacing_interface::right_column (sp) != rc)
 149             continue;
 150
 151           if (Note_spacing::has_interface (sp))
 152             {
 153               /*
 154                 The note spacing should be taken from the musical
 155                 columns.
 156               */
 157               Real base = note_spacing (me, lc, rc, options);
 158               Spring spring = Note_spacing::get_spacing (sp, rc, base, options->increment_);
 159
 160               dists[d] = max (dists[d], spring.min_distance ());
 161             }
 162           else if (Staff_spacing::has_interface (sp))
 163             {
 164               Spring spring = Staff_spacing::get_spacing (sp, rc);
 165
 166               dists[d] = max (dists[d], spring.min_distance ());
 167             }
 168           else
 169             programming_error ("Subversive spacing wish");
 170         }
 171     }
 172   while (flip (&d) != LEFT);
 173
 174   Rod r;
 175   r.distance_ = dists[LEFT] + dists[RIGHT];
 176   r.item_drul_ = next_door;
 177
 178   r.add_to_cols ();
 179 }
 180
 181
 182 /*
 183   Remove columns that are not tightly fitting from COLS. In the
 184   removed columns, set 'between-cols to the columns where it is in
 185   between.
 186 */
 187 void
 188 Spacing_spanner::prune_loose_columns (Grob *me,
 189                                       vector<Grob*> *cols,
 190                                       Spacing_options *options)
 191 {
 192   vector<Grob*> newcols;
 193
 194   for (vsize i = 0; i < cols->size (); i++)
 195     {
 196       Grob *c = cols->at (i);
 197
 198       bool loose = (i > 0 && i + 1 < cols->size ())
 199         && is_loose_column (cols->at (i - 1), c, cols->at (i + 1), options);
 200
 201       if (loose)
 202         {
 203           extract_grob_set (c, "right-neighbors", rns_arr);
 204           extract_grob_set (c, "left-neighbors", lns_arr);
 205
 206           SCM lns = lns_arr.size () ? lns_arr.back ()->self_scm () : SCM_BOOL_F;
 207           SCM rns = rns_arr.size () ? rns_arr.back ()->self_scm () : SCM_BOOL_F;
 208
 209           /*
 210             Either object can be non existent, if the score ends
 211             prematurely.
 212           */
 213
 214           extract_grob_set (unsmob_grob (rns), "right-items", right_items);
 215           if (right_items.size () == 0 || !unsmob_grob (lns))
 216             {
 217               c->programming_error ("Cannot determine neighbors for floating column. ");
 218               c->set_object ("between-cols", scm_cons (cols->at (i-1)->self_scm (),
 219                                                        cols->at (i+1)->self_scm ()));
 220             }
 221           else
 222             {
 223               Grob *min_item = 0;
 224               int min_rank = INT_MAX;
 225               for (vsize j = 0; j < right_items.size (); j ++)
 226                 {
 227                   int rank = dynamic_cast<Item*> (right_items[j])->get_column ()->get_rank ();
 228                   if (rank < min_rank)
 229                     {
 230                       min_item = right_items[j];
 231                       min_rank = rank;
 232                     }
 233                 }
 234
 235               c->set_object ("between-cols", scm_cons (lns,
 236                                                        min_item->self_scm ()));
 237
 238               /*
 239                 Set distance constraints for loose columns
 240               */
 241               Drul_array<Item *> next_door (dynamic_cast<Item*> (cols->at (i - 1)),
 242                                             dynamic_cast<Item*> (cols->at (i + 1)));
 243
 244               set_distances_for_loose_col (me, c, next_door, options);
 245             }
 246         }
 247
 248       if (!loose)
 249         newcols.push_back (c);
 250     }
 251
 252   *cols = newcols;
 253 }
 254
 255 /*
 256   Set neighboring columns determined by the spacing-wishes grob property.
 257 */
 258 void
 259 Spacing_spanner::set_explicit_neighbor_columns (vector<Grob*> const &cols)
 260 {
 261   for (vsize i = 0; i < cols.size (); i++)
 262     {
 263       SCM right_neighbors = Grob_array::make_array ();
 264       Grob_array *rn_arr = unsmob_grob_array (right_neighbors);
 265       int min_rank = INT_MAX;
 266
 267       extract_grob_set (cols[i], "spacing-wishes", wishes);
 268       for (vsize k = wishes.size (); k--;)
 269         {
 270           Item *wish = dynamic_cast<Item *> (wishes[k]);
 271
 272           Item *lc = wish->get_column ();
 273           Grob *right = Spacing_interface::right_column (wish);
 274
 275           if (!right)
 276             continue;
 277
 278           Item *rc = dynamic_cast<Item *> (right);
 279
 280           int right_rank = Paper_column::get_rank (rc);
 281           int left_rank = Paper_column::get_rank (lc);
 282
 283           /*
 284             update the left column.
 285           */
 286           if (right_rank <= min_rank)
 287             {
 288               if (right_rank < min_rank)
 289                 rn_arr->clear ();
 290
 291               min_rank = right_rank;
 292               rn_arr->add (wish);
 293             }
 294
 295           /*
 296             update the right column of the wish.
 297           */
 298           int maxrank = 0;
 299
 300           extract_grob_set (rc, "left-neighbors", lns_arr);
 301           if (lns_arr.size ())
 302             {
 303               Item *it = dynamic_cast<Item *> (lns_arr.back ());
 304               maxrank = Paper_column::get_rank (it->get_column ());
 305             }
 306
 307           if (left_rank >= maxrank)
 308             {
 309
 310               if (left_rank > maxrank)
 311                 {
 312                   Grob_array *ga = unsmob_grob_array (rc->get_object ("left-neighbors"));
 313                   if (ga)
 314                     ga->clear ();
 315                 }
 316
 317               Pointer_group_interface::add_grob (rc, ly_symbol2scm ("left-neighbors"), wish);
 318             }
 319         }
 320
 321       if (rn_arr->size ())
 322         cols[i]->set_object ("right-neighbors", right_neighbors);
 323     }
 324 }
 325
 326 /*
 327   Set neighboring columns that have no left/right-neighbor set
 328   yet. Only do breakable non-musical columns, and musical columns.
 329 */
 330 void
 331 Spacing_spanner::set_implicit_neighbor_columns (vector<Grob*> const &cols)
 332 {
 333   for (vsize i = 0; i < cols.size (); i++)
 334     {
 335       Item *it = dynamic_cast<Item *> (cols[i]);
 336       if (!Paper_column::is_breakable (it) && !Paper_column::is_musical (it))
 337         continue;
 338
 339       /*
 340         sloppy with typing left/right-neighbors should take list, but paper-column found instead.
 341       */
 342       extract_grob_set (cols[i], "left-neighbors", lns);
 343       if (lns.empty () && i)
 344         {
 345           SCM ga_scm = Grob_array::make_array ();
 346           Grob_array *ga = unsmob_grob_array (ga_scm);
 347           ga->add (cols[i - 1]);
 348           cols[i]->set_object ("left-neighbors", ga_scm);
 349         }
 350       extract_grob_set (cols[i], "right-neighbors", rns);
 351       if (rns.empty () && i + 1 < cols.size ())
 352         {
 353           SCM ga_scm = Grob_array::make_array ();
 354           Grob_array *ga = unsmob_grob_array (ga_scm);
 355           ga->add (cols[i + 1]);
 356           cols[i]->set_object ("right-neighbors", ga_scm);
 357         }
 358     }
 359 }