lily/spacing-determine-loose-columns.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2005--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "staff-spacing.hh"
  21
  22 #include "spacing-options.hh"
  23 #include "system.hh"
  24 #include "paper-column.hh"
  25 #include "column-x-positions.hh"
  26 #include "pointer-group-interface.hh"
  27 #include "spacing-interface.hh"
  28 #include "spacing-spanner.hh"
  29 #include "note-spacing.hh"
  30 #include "moment.hh"
  31 #include "grob-array.hh"
  32 #include "break-align-interface.hh"
  33 #include "warn.hh"
  34
  35 /*
  36   Return whether COL is fixed to its neighbors by some kind of spacing
  37   constraint.
  38
  39
  40   If in doubt, then we're not loose; the spacing engine should space
  41   for it, risking suboptimal spacing.
  42
  43   (Otherwise, we might risk core dumps, and other weird stuff.)
  44 */
  45 static bool
  46 is_loose_column (Grob *l, Grob *col, Grob *r, Spacing_options const *options)
  47 {
  48   if (!to_boolean (col->get_property ("allow-loose-spacing")))
  49     return false;
  50
  51
  52   if ((options->float_nonmusical_columns_
  53        || options->float_grace_columns_)
  54       && Paper_column::when_mom (col).grace_part_)
  55     {
  56       return true;
  57     }
  58
  59
  60   if (Paper_column::is_musical (col))
  61     return false;
  62
  63   /*
  64     If this column doesn't have a proper neighbor, we should really
  65     make it loose, but spacing it correctly is more than we can
  66     currently can handle.
  67
  68     (this happens in the following situation:
  69
  70     |
  71     |    clef G
  72     *
  73
  74     |               |      ||
  75     |               |      ||
  76     O               O       ||
  77
  78
  79     the column containing the clef is really loose, and should be
  80     attached right to the first column, but that is a lot of work for
  81     such a borderline case.)
  82
  83   */
  84
  85   Item *r_neighbor = unsmob_item (col->get_object ("right-neighbor"));
  86   Item *l_neighbor = unsmob_item (col->get_object ("left-neighbor"));
  87
  88   if (!l_neighbor || !r_neighbor)
  89     return false;
  90
  91   /* If a non-empty column (ie. not \bar "") is placed nicely in series with
  92      its neighbor (ie. no funny polyphonic stuff), don't make it loose.
  93   */
  94   if (l == l_neighbor && r == r_neighbor && col->extent (col, X_AXIS).length () > 0)
  95      return false;
  96
  97   /*
  98     Only declare loose if the bounds make a little sense.  This means
  99     some cases (two isolated, consecutive clef changes) won't be
 100     nicely folded, but hey, then don't do that.
 101   */
 102   if (! ((Paper_column::is_musical (l_neighbor) || Paper_column::is_breakable (l_neighbor))
 103          && (Paper_column::is_musical (r_neighbor) || Paper_column::is_breakable (r_neighbor))))
 104     return false;
 105
 106   /*
 107     in any case, we don't want to move bar lines.
 108   */
 109   extract_grob_set (col, "elements", elts);
 110   for (vsize i = elts.size (); i--;)
 111     {
 112       Grob *g = elts[i];
 113       if (g && Break_alignment_interface::has_interface (g))
 114         {
 115           extract_grob_set (g, "elements", gelts);
 116           for (vsize j = gelts.size (); j--;)
 117             {
 118               Grob *h = gelts[j];
 119
 120               if (h && h->get_property ("break-align-symbol") == ly_symbol2scm ("staff-bar"))
 121                 {
 122                   extract_grob_set (h, "elements", helts);
 123                   for (vsize k = helts.size (); k--;)
 124                     if ("" != robust_scm2string (helts[k]->get_property ("glyph-name"), ""))
 125                       return false;
 126                 }
 127             }
 128         }
 129     }
 130
 131   return true;
 132 }
 133
 134 void
 135 Spacing_spanner::set_distances_for_loose_col (Grob *me, Grob *c,
 136                                               Drul_array<Item *> next_door,
 137                                               Spacing_options const *options)
 138 {
 139   Direction d = LEFT;
 140   Drul_array<Real> dists (0, 0);
 141
 142   do
 143     {
 144       Item *lc = dynamic_cast<Item *> ((d == LEFT) ? next_door[LEFT] : c);
 145       Item *rc = dynamic_cast<Item *> (d == LEFT ? c : next_door[RIGHT]);
 146
 147       extract_grob_set (lc, "spacing-wishes", wishes);
 148       for (vsize k = wishes.size (); k--;)
 149         {
 150           Grob *sp = wishes[k];
 151           if (Spacing_interface::left_column (sp) != lc
 152               || Spacing_interface::right_column (sp) != rc)
 153             continue;
 154
 155           if (Note_spacing::has_interface (sp))
 156             {
 157               /*
 158                 The note spacing should be taken from the musical
 159                 columns.
 160               */
 161               Real base = note_spacing (me, lc, rc, options);
 162               Spring spring = Note_spacing::get_spacing (sp, rc, base, options->increment_);
 163
 164               dists[d] = max (dists[d], spring.min_distance ());
 165             }
 166           else if (Staff_spacing::has_interface (sp))
 167             {
 168               Spring spring = Staff_spacing::get_spacing (sp, rc);
 169
 170               dists[d] = max (dists[d], spring.min_distance ());
 171             }
 172           else
 173             programming_error ("Subversive spacing wish");
 174         }
 175     }
 176   while (flip (&d) != LEFT);
 177
 178   Rod r;
 179   r.distance_ = dists[LEFT] + dists[RIGHT];
 180   r.item_drul_ = next_door;
 181
 182   r.add_to_cols ();
 183 }
 184
 185
 186 /*
 187   Remove columns that are not tightly fitting from COLS. In the
 188   removed columns, set 'between-cols to the columns where it is in
 189   between.
 190 */
 191 void
 192 Spacing_spanner::prune_loose_columns (Grob *me,
 193                                       vector<Grob*> *cols,
 194                                       Spacing_options *options)
 195 {
 196   vector<Grob*> newcols;
 197
 198   for (vsize i = 0; i < cols->size (); i++)
 199     {
 200       Grob *c = cols->at (i);
 201
 202       bool loose = (i > 0 && i + 1 < cols->size ())
 203         && is_loose_column (cols->at (i - 1), c, cols->at (i + 1), options);
 204
 205       /* Breakable columns never get pruned; even if they are loose,
 206         their broken pieces are not.  However, we mark them so that
 207         the spacing can take their mid-line looseness into account. */
 208       if (loose && Paper_column::is_breakable (c))
 209         {
 210           loose = false;
 211           c->set_property ("maybe-loose", SCM_BOOL_T);
 212         }
 213       /*
 214         Unbreakable columns which only contain page-labels also
 215         never get pruned, otherwise the labels are lost before they can
 216         be collected by the System: so we mark these columns too.
 217       */
 218       if (!loose && !Paper_column::is_breakable (c)
 219           && scm_is_pair (c->get_property ("labels")))
 220         {
 221           extract_grob_set (c, "elements", elts);
 222           if (elts.empty ())
 223             c->set_property ("maybe-loose", SCM_BOOL_T);
 224         }
 225
 226       if (loose)
 227         {
 228           Grob *right_neighbor = unsmob_grob (c->get_object ("right-neighbor"));
 229           Grob *left_neighbor = unsmob_grob (c->get_object ("left-neighbor"));
 230
 231           /*
 232             Either object can be non existent, if the score ends
 233             prematurely.
 234           */
 235           if (!right_neighbor || !left_neighbor)
 236             {
 237               c->programming_error ("Cannot determine neighbors for floating column. ");
 238               c->set_object ("between-cols", scm_cons (cols->at (i-1)->self_scm (),
 239                                                        cols->at (i+1)->self_scm ()));
 240             }
 241           else
 242             {
 243               c->set_object ("between-cols", scm_cons (left_neighbor->self_scm (),
 244                                                        right_neighbor->self_scm ()));
 245
 246
 247               /*
 248                 Set distance constraints for loose columns
 249               */
 250               Drul_array<Item *> next_door (dynamic_cast<Item*> (cols->at (i - 1)),
 251                                             dynamic_cast<Item*> (cols->at (i + 1)));
 252
 253               set_distances_for_loose_col (me, c, next_door, options);
 254             }
 255         }
 256
 257       if (!loose)
 258         newcols.push_back (c);
 259     }
 260
 261   *cols = newcols;
 262 }
 263
 264 /*
 265   Set neighboring columns determined by the spacing-wishes grob property.
 266 */
 267 void
 268 Spacing_spanner::set_explicit_neighbor_columns (vector<Grob*> const &cols)
 269 {
 270   for (vsize i = 0; i < cols.size (); i++)
 271     {
 272       extract_grob_set (cols[i], "spacing-wishes", wishes);
 273       for (vsize j = wishes.size (); j--;)
 274         {
 275           Item *wish = dynamic_cast<Item*> (wishes[j]);
 276           Item *left_col = wish->get_column ();
 277           int left_rank = Paper_column::get_rank (left_col);
 278           int min_right_rank = INT_MAX;
 279
 280           extract_grob_set (wish, "right-items", right_items);
 281           for (vsize k = right_items.size (); k--;)
 282             {
 283               Item *right_col = dynamic_cast<Item*> (right_items[k])->get_column ();
 284               int right_rank = Paper_column::get_rank (right_col);
 285
 286               if (right_rank < min_right_rank)
 287                 {
 288                   left_col->set_object ("right-neighbor", right_col->self_scm ());
 289                   min_right_rank = right_rank;
 290                 }
 291
 292               Grob *old_left_neighbor = unsmob_grob (right_col->get_object ("left-neighbor"));
 293               if (!old_left_neighbor || left_rank > Paper_column::get_rank (old_left_neighbor))
 294                 right_col->set_object ("left-neighbor", left_col->self_scm ());
 295             }
 296         }
 297     }
 298 }
 299
 300 /*
 301   Set neighboring columns that have no left/right-neighbor set
 302   yet. Only do breakable non-musical columns, and musical columns.
 303   Why only these? --jneem
 304 */
 305 void
 306 Spacing_spanner::set_implicit_neighbor_columns (vector<Grob*> const &cols)
 307 {
 308   for (vsize i = 0; i < cols.size (); i++)
 309     {
 310       Item *it = dynamic_cast<Item *> (cols[i]);
 311       if (!Paper_column::is_breakable (it) && !Paper_column::is_musical (it))
 312         continue;
 313
 314       if (i && !unsmob_grob (cols[i]->get_object ("left-neighbor")))
 315         cols[i]->set_object ("left-neighbor", cols[i-1]->self_scm ());
 316       if (i + 1 < cols.size () && !unsmob_grob (cols[i]->get_object ("right-neighbor")))
 317         cols[i]->set_object ("right-neighbor", cols[i+1]->self_scm ());
 318     }
 319 }