lily/note-collision.cc

   1 /*
   2   collision.cc -- implement Collision
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "note-collision.hh"
  10
  11 #include "axis-group-interface.hh"
  12 #include "dot-column.hh"
  13 #include "international.hh"
  14 #include "note-column.hh"
  15 #include "note-head.hh"
  16 #include "output-def.hh"
  17 #include "pointer-group-interface.hh"
  18 #include "rhythmic-head.hh"
  19 #include "staff-symbol-referencer.hh"
  20 #include "side-position-interface.hh"
  21 #include "stem.hh"
  22 #include "warn.hh"
  23
  24
  25 void
  26 check_meshing_chords (Grob *me,
  27                       Drul_array<vector<Real> > *offsets,
  28                       Drul_array<vector<Slice> > const &extents,
  29                       Drul_array<vector<Grob*> > const &clash_groups)
  30
  31 {
  32   if (!extents[UP].size () || ! extents[DOWN].size ())
  33     return;
  34
  35   Grob *cu = clash_groups[UP][0];
  36   Grob *cd = clash_groups[DOWN][0];
  37
  38   /* Every note column should have a stem, but avoid a crash. */
  39   if (!Note_column::get_stem (cu) || !Note_column::get_stem (cd))
  40     return;
  41
  42   Drul_array<Grob*> stems (Note_column::get_stem (cd),
  43                            Note_column::get_stem (cu));
  44
  45   Grob *nu = Note_column::first_head (cu);
  46   Grob *nd = Note_column::first_head (cd);
  47
  48   vector<int> ups = Stem::note_head_positions (Note_column::get_stem (cu));
  49   vector<int> dps = Stem::note_head_positions (Note_column::get_stem (cd));
  50
  51   /* Too far apart to collide.  */
  52   if (ups[0] > dps.back () + 1)
  53     return;
  54
  55   /* Merge heads if the notes lie the same line, or if the "stem-up-note" is
  56      above the "stem-down-note". */
  57   bool merge_possible = (ups[0] >= dps[0]) && (ups.back () >= dps.back ());
  58
  59   /* Do not merge notes typeset in different style. */
  60   if (!ly_is_equal (nu->get_property ("style"),
  61                     nd->get_property ("style")))
  62     merge_possible = false;
  63
  64   int upball_type = Rhythmic_head::duration_log (nu);
  65   int dnball_type = Rhythmic_head::duration_log (nd);
  66
  67   /* Do not merge whole notes (or longer, like breve, longa, maxima).  */
  68   if (merge_possible && (upball_type <= 0 || dnball_type <= 0))
  69     merge_possible = false;
  70
  71   if (merge_possible
  72       && Rhythmic_head::dot_count (nu) != Rhythmic_head::dot_count (nd)
  73       && !to_boolean (me->get_property ("merge-differently-dotted")))
  74     merge_possible = false;
  75
  76   /* Can only merge different heads if merge-differently-headed is
  77      set. */
  78   if (merge_possible
  79       && upball_type != dnball_type
  80       && !to_boolean (me->get_property ("merge-differently-headed")))
  81     merge_possible = false;
  82
  83   if (merge_possible
  84       && nu->get_property ("style") == ly_symbol2scm ("fa")
  85       && nd->get_property ("style") == ly_symbol2scm ("fa"))
  86     {
  87       Interval uphead_size = nu->extent (nu, Y_AXIS);
  88       Offset att =  Offset (0.0, -1.0);
  89       nu->set_property ("stem-attachment", ly_offset2scm (att));
  90       nu->set_property ("transparent", SCM_BOOL_T);
  91     }
  92
  93   /* Should never merge quarter and half notes, as this would make
  94      them indistinguishable.  */
  95   if (merge_possible
  96       && ((Stem::duration_log (stems[UP]) == 1
  97            && Stem::duration_log (stems[DOWN]) == 2)
  98           || (Stem::duration_log (stems[UP]) == 2
  99               && Stem::duration_log (stems[DOWN]) == 1)))
 100     merge_possible = false;
 101
 102   /*
 103     this case (distant half collide),
 104
 105     |
 106     x |
 107     | x
 108     |
 109
 110     the noteheads may be closer than this case (close half collide)
 111
 112     |
 113     |
 114     x
 115     x
 116     |
 117     |
 118
 119   */
 120
 121   /* TODO: filter out the 'o's in this configuration, since they're no
 122      part in the collision.
 123
 124      |
 125      x|o
 126      x|o
 127      x
 128
 129   */
 130
 131   bool close_half_collide = false;
 132   bool distant_half_collide = false;
 133   bool full_collide = false;
 134
 135   for (vsize i = 0, j = 0; i < ups.size () && j < dps.size (); )
 136     {
 137       if (abs (ups[i] - dps[j]) == 1)
 138         {
 139           merge_possible = false;
 140           if (ups[i] > dps[j])
 141             close_half_collide = true;
 142           else
 143             distant_half_collide = true;
 144         }
 145       else if (ups[i] == dps[j])
 146         full_collide = true;
 147       else if (ups[i] > dps[0] && ups[i] < dps.back ())
 148         merge_possible = false;
 149       else if (dps[j] > ups[0] && dps[j] < ups.back ())
 150         merge_possible = false;
 151
 152       if (ups[i] < dps[j])
 153         i++;
 154       else if (ups[i] > dps[j])
 155         j++;
 156       else
 157         {
 158           i++;
 159           j++;
 160         }
 161     }
 162
 163   full_collide = full_collide || (close_half_collide
 164                                   && distant_half_collide);
 165
 166   Drul_array<Real> center_note_shifts;
 167   center_note_shifts[LEFT] = 0.0;
 168   center_note_shifts[RIGHT] = 0.0;
 169
 170   Real shift_amount = 1;
 171
 172   bool touch = (ups[0] >= dps.back ());
 173   if (touch)
 174     shift_amount *= -1;
 175
 176   /* For full collisions, the right hand head may obscure dots, so
 177      make sure the dotted heads go to the right.  */
 178   bool stem_to_stem = false;
 179   if (full_collide)
 180     if (Rhythmic_head::dot_count (nu) > Rhythmic_head::dot_count (nd))
 181       shift_amount = 1;
 182     else if (Rhythmic_head::dot_count (nu) < Rhythmic_head::dot_count (nd))
 183       stem_to_stem = true;
 184
 185   if (merge_possible)
 186     {
 187       shift_amount = 0;
 188
 189       /* If possible, don't wipe any heads. Else, wipe shortest head,
 190          or head with smallest amount of dots.  Note: when merging
 191          different heads, dots on the smaller one disappear. */
 192       Grob *wipe_ball = 0;
 193       Grob *dot_wipe_head = nu;
 194
 195       if (upball_type == dnball_type)
 196         {
 197           if (Rhythmic_head::dot_count (nd) < Rhythmic_head::dot_count (nu))
 198             {
 199               wipe_ball = nd;
 200               dot_wipe_head = nd;
 201             }
 202           else if (Rhythmic_head::dot_count (nd) > Rhythmic_head::dot_count (nu))
 203             {
 204               dot_wipe_head = nu;
 205               wipe_ball = nu;
 206             }
 207           else
 208             dot_wipe_head = nu;
 209         }
 210       else if (dnball_type > upball_type)
 211         {
 212           wipe_ball = nd;
 213           dot_wipe_head = nd;
 214         }
 215       else if (dnball_type < upball_type)
 216         {
 217           wipe_ball = nu;
 218           dot_wipe_head = nu;
 219         }
 220
 221       if (dot_wipe_head)
 222         {
 223           if (Grob *d = unsmob_grob (dot_wipe_head->get_object ("dot")))
 224             d->suicide ();
 225         }
 226
 227       if (wipe_ball && wipe_ball->is_live ())
 228         {
 229           wipe_ball->set_property ("transparent", SCM_BOOL_T);
 230         }
 231     }
 232   /* TODO: these numbers are magic; should devise a set of grob props
 233      to tune this behavior.  */
 234   else if (stem_to_stem)
 235     shift_amount = -abs (shift_amount) * 0.65;
 236   else if (close_half_collide && !touch)
 237     shift_amount *= 0.52;
 238   else if (distant_half_collide && !touch)
 239     shift_amount *= 0.4;
 240   else if (distant_half_collide || close_half_collide || full_collide)
 241     shift_amount *= 0.5;
 242
 243   /* we're meshing.  */
 244   else if (Rhythmic_head::dot_count (nu) || Rhythmic_head::dot_count (nd))
 245     shift_amount *= 0.1;
 246   else
 247     shift_amount *= 0.17;
 248
 249   /*
 250    * Fix issue #44:
 251    *
 252    * Dots from left note head collide with right note head. Only occurs
 253    * with a close half collide, if the left note head is between
 254    * lines and the right note head is on a line, and if right note head
 255    * hasn't got any dots.
 256    */
 257   if (close_half_collide
 258       && Rhythmic_head::dot_count (nu)
 259       && !Rhythmic_head::dot_count (nd))
 260     {
 261       Grob *staff = Staff_symbol_referencer::get_staff_symbol (me);
 262       if (!Staff_symbol_referencer::on_line (staff, ups[0]))
 263         {
 264           Grob *d = unsmob_grob (nu->get_object ("dot"));
 265           Grob *parent = d->get_parent (X_AXIS);
 266           if (Dot_column::has_interface (parent))
 267             Side_position_interface::add_support (parent, nd);
 268         }
 269     }
 270
 271   /* For full or close half collisions, the right hand head may
 272      obscure dots.  Move dots to the right.  */
 273   if (abs (shift_amount) > 1e-6
 274       && Rhythmic_head::dot_count (nd) > Rhythmic_head::dot_count (nu)
 275       && (full_collide || close_half_collide))
 276     {
 277       Grob *d = unsmob_grob (nd->get_object ("dot"));
 278       Grob *parent = d->get_parent (X_AXIS);
 279
 280       /*
 281         FIXME:
 282
 283         |
 284         x . o
 285         |
 286
 287
 288         the . is put right of o which is erroneous o force-shifted
 289         far to the right.
 290       */
 291       if (Dot_column::has_interface (parent))
 292         Side_position_interface::add_support (parent, nu);
 293     }
 294
 295   Direction d = UP;
 296   do
 297     {
 298       for (vsize i = 0; i < clash_groups[d].size (); i++)
 299         (*offsets)[d][i] += d * shift_amount;
 300     }
 301   while ((flip (&d)) != UP);
 302 }
 303
 304
 305 MAKE_SCHEME_CALLBACK(Note_collision_interface, calc_positioning_done, 1)
 306 SCM
 307 Note_collision_interface::calc_positioning_done (SCM smob)
 308 {
 309   Grob *me = unsmob_grob (smob);
 310   Drul_array<vector<Grob*> > cg = get_clash_groups (me);
 311
 312   Direction d = UP;
 313   do
 314     {
 315       for (vsize i = cg[d].size(); i--; )
 316         {
 317           /*
 318             Trigger positioning
 319            */
 320           cg[d][i]->extent (me, X_AXIS);
 321         }
 322     }
 323   while (flip (&d) != UP);
 324
 325   SCM autos (automatic_shift (me, cg));
 326   SCM hand (forced_shift (me));
 327
 328   Real wid = 0.0;
 329   do
 330     {
 331       if (cg[d].size ())
 332         {
 333           Grob *h = cg[d][0];
 334           Grob *fh = Note_column::first_head (h);
 335           if (fh)
 336             wid = fh->extent (h, X_AXIS).length ();
 337         }
 338     }
 339   while (flip (&d) != UP);
 340
 341   vector<Grob*> done;
 342   Real left_most = 1e6;
 343
 344   vector<Real> amounts;
 345   for (; scm_is_pair (hand); hand = scm_cdr (hand))
 346     {
 347       Grob *s = unsmob_grob (scm_caar (hand));
 348       Real amount = scm_to_double (scm_cdar (hand)) * wid;
 349
 350       done.push_back (s);
 351       amounts.push_back (amount);
 352       if (amount < left_most)
 353         left_most = amount;
 354     }
 355   for (; scm_is_pair (autos); autos = scm_cdr (autos))
 356     {
 357       Grob *s = unsmob_grob (scm_caar (autos));
 358       Real amount = scm_to_double (scm_cdar (autos)) * wid;
 359
 360       vsize x = find (done, s) - done.begin ();
 361       if (x == VPOS || x >= done.size ())
 362         {
 363           done.push_back (s);
 364           amounts.push_back (amount);
 365           if (amount < left_most)
 366             left_most = amount;
 367         }
 368     }
 369
 370   for (vsize i = 0; i < amounts.size (); i++)
 371     done[i]->translate_axis (amounts[i] - left_most, X_AXIS);
 372
 373   return SCM_BOOL_T;
 374 }
 375
 376 Drul_array < vector<Grob*> >
 377 Note_collision_interface::get_clash_groups (Grob *me)
 378 {
 379   Drul_array<vector<Grob*> > clash_groups;
 380
 381   extract_grob_set (me, "elements", elements);
 382   for (vsize i = 0; i < elements.size (); i++)
 383     {
 384       Grob *se = elements[i];
 385       if (Note_column::has_interface (se))
 386         {
 387           if (!Note_column::dir (se))
 388             {
 389               se->programming_error ("note-column has no direction");
 390             }
 391           else
 392             clash_groups[Note_column::dir (se)].push_back (se);
 393         }
 394     }
 395
 396   Direction d = UP;
 397   do
 398     {
 399       vector<Grob*> &clashes (clash_groups[d]);
 400       vector_sort (clashes, Note_column::shift_less);
 401     }
 402   while ((flip (&d)) != UP);
 403
 404   return clash_groups;
 405 }
 406
 407 /** This complicated routine moves note columns around horizontally to
 408     ensure that notes don't clash.
 409
 410     This should be put into Scheme.
 411 */
 412 SCM
 413 Note_collision_interface::automatic_shift (Grob *me,
 414                                            Drul_array < vector<Grob*>
 415                                            > clash_groups)
 416 {
 417   Drul_array < vector<int> > shifts;
 418   SCM tups = SCM_EOL;
 419
 420   Direction d = UP;
 421   do
 422     {
 423       vector<int> &shift (shifts[d]);
 424       vector<Grob*> &clashes (clash_groups[d]);
 425
 426       for (vsize i = 0; i < clashes.size (); i++)
 427         {
 428           SCM sh
 429             = clashes[i]->get_property ("horizontal-shift");
 430
 431           if (scm_is_number (sh))
 432             shift.push_back (scm_to_int (sh));
 433           else
 434             shift.push_back (0);
 435         }
 436
 437       for (vsize i = 1; i < shift.size (); i++)
 438         {
 439           if (shift[i - 1] == shift[i])
 440             {
 441               clashes[0]->warning (_ ("ignoring too many clashing note columns"));
 442               return tups;
 443             }
 444         }
 445     }
 446   while ((flip (&d)) != UP);
 447
 448   Drul_array<vector<Slice> > extents;
 449   Drul_array<vector<Real> > offsets;
 450   d = UP;
 451   do
 452     {
 453       for (vsize i = 0; i < clash_groups[d].size (); i++)
 454         {
 455           Slice s (Note_column::head_positions_interval (clash_groups[d][i]));
 456           s[LEFT]--;
 457           s[RIGHT]++;
 458           extents[d].push_back (s);
 459           offsets[d].push_back (d * 0.5 * i);
 460         }
 461     }
 462   while ((flip (&d)) != UP);
 463
 464   /*
 465     do horizontal shifts of each direction
 466
 467     |
 468     x||
 469     x||
 470     x|
 471   */
 472
 473   do
 474     {
 475       for (vsize i = 1; i < clash_groups[d].size (); i++)
 476         {
 477           Slice prev = extents[d][i - 1];
 478           prev.intersect (extents[d][i]);
 479           if (prev.length () > 0
 480               || (extents[-d].size () && d * (extents[d][i][-d] - extents[-d][0][d]) < 0))
 481             for (vsize j = i; j < clash_groups[d].size (); j++)
 482               offsets[d][j] += d * 0.5;
 483         }
 484     }
 485   while ((flip (&d)) != UP);
 486
 487   /*
 488     Check if chords are meshing
 489   */
 490
 491   check_meshing_chords (me, &offsets, extents, clash_groups);
 492
 493   do
 494     {
 495       for (vsize i = 0; i < clash_groups[d].size (); i++)
 496         tups = scm_cons (scm_cons (clash_groups[d][i]->self_scm (),
 497                                    scm_from_double (offsets[d][i])),
 498                          tups);
 499     }
 500   while (flip (&d) != UP);
 501
 502   return tups;
 503 }
 504
 505 SCM
 506 Note_collision_interface::forced_shift (Grob *me)
 507 {
 508   SCM tups = SCM_EOL;
 509
 510   extract_grob_set (me, "elements", elements);
 511   for (vsize i = 0; i < elements.size (); i++)
 512     {
 513       Grob *se = elements[i];
 514
 515       SCM force = se->get_property ("force-hshift");
 516       if (scm_is_number (force))
 517         {
 518           tups = scm_cons (scm_cons (se->self_scm (), force),
 519                            tups);
 520         }
 521     }
 522   return tups;
 523 }
 524
 525 void
 526 Note_collision_interface::add_column (Grob *me, Grob *ncol)
 527 {
 528   ncol->set_property ("X-offset", Grob::x_parent_positioning_proc);
 529   Axis_group_interface::add_element (me, ncol);
 530 }
 531
 532 ADD_INTERFACE (Note_collision_interface, "note-collision-interface",
 533                "An object that handles collisions between notes with different stem "
 534                "directions and horizontal shifts. Most of the interesting properties "
 535                "are to be set in @ref{note-column-interface}: these are "
 536                "@code{force-hshift} and @code{horizontal-shift}.",
 537
 538                /* properties */
 539                "merge-differently-dotted "
 540                "merge-differently-headed "
 541                "positioning-done ");