lily/note-collision.cc

   1 /*
   2   collision.cc -- implement Collision
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "note-collision.hh"
  10
  11 #include <math.h>
  12
  13 #include "warn.hh"
  14 #include "note-column.hh"
  15 #include "note-head.hh"
  16 #include "rhythmic-head.hh"
  17 #include "output-def.hh"
  18 #include "axis-group-interface.hh"
  19 #include "stem.hh"
  20 #include "side-position-interface.hh"
  21 #include "dot-column.hh"
  22
  23 MAKE_SCHEME_CALLBACK (Note_collision_interface, force_shift_callback, 2);
  24
  25 SCM
  26 Note_collision_interface::force_shift_callback (SCM element_smob, SCM axis)
  27 {
  28   Grob *me = unsmob_grob (element_smob);
  29   Axis a = (Axis) scm_to_int (axis);
  30   assert (a == X_AXIS);
  31
  32   me = me->get_parent (a);
  33
  34   if (! to_boolean (me->get_property ("positioning-done")))
  35     {
  36       me->set_property ("positioning-done", SCM_BOOL_T);
  37       do_shifts (me);
  38     }
  39
  40   return scm_make_real (0.0);
  41 }
  42
  43 void
  44 check_meshing_chords (Grob *me,
  45                       Drul_array<Array<Real> > *offsets,
  46                       Drul_array<Array<Slice> > const &extents,
  47                       Drul_array<Link_array<Grob> > const &clash_groups)
  48
  49 {
  50   if (!extents[UP].size () || ! extents[DOWN].size ())
  51     return;
  52
  53   Grob *cu = clash_groups[UP][0];
  54   Grob *cd = clash_groups[DOWN][0];
  55
  56   /* Every note column should have a stem, but avoid a crash. */
  57   if (!Note_column::get_stem (cu) || !Note_column::get_stem (cd))
  58     return;
  59
  60   Grob *nu = Note_column::first_head (cu);
  61   Grob *nd = Note_column::first_head (cd);
  62
  63   Array<int> ups = Stem::note_head_positions (Note_column::get_stem (cu));
  64   Array<int> dps = Stem::note_head_positions (Note_column::get_stem (cd));
  65
  66   /* Too far apart to collide.  */
  67   if (ups[0] > dps.top () + 1)
  68     return;
  69
  70   // FIXME: what's this?
  71   bool merge_possible = (ups[0] >= dps[0]) && (ups.top () >= dps.top ());
  72
  73   /* Do not merge notes typeset in different style. */
  74   if (!ly_c_equal_p (nu->get_property ("style"),
  75                      nd->get_property ("style")))
  76     merge_possible = false;
  77
  78   int upball_type = Note_head::get_balltype (nu);
  79   int dnball_type = Note_head::get_balltype (nd);
  80
  81   /* Do not merge whole notes (or longer, like breve, longa, maxima).  */
  82   if (merge_possible && (upball_type <= 0 || dnball_type <= 0))
  83     merge_possible = false;
  84
  85   if (merge_possible
  86       && Rhythmic_head::dot_count (nu) != Rhythmic_head::dot_count (nd)
  87       && !to_boolean (me->get_property ("merge-differently-dotted")))
  88     merge_possible = false;
  89
  90   /* Can only merge different heads if merge-differently-headed is
  91      set. */
  92   if (merge_possible
  93       && upball_type != dnball_type
  94       && !to_boolean (me->get_property ("merge-differently-headed")))
  95     merge_possible = false;
  96
  97   /* Should never merge quarter and half notes, as this would make
  98      them indistinguishable.  */
  99   if (merge_possible
 100       && ((Rhythmic_head::duration_log (nu) == 1
 101            && Rhythmic_head::duration_log (nd) == 2)
 102           || (Rhythmic_head::duration_log (nu) == 2
 103               && Rhythmic_head::duration_log (nd) == 1)))
 104     merge_possible = false;
 105
 106   /*
 107     this case (distant half collide),
 108
 109     |
 110     x |
 111     | x
 112     |
 113
 114     the noteheads may be closer than this case (close half collide)
 115
 116     |
 117     |
 118     x
 119     x
 120     |
 121     |
 122
 123   */
 124
 125   /* TODO: filter out the 'o's in this configuration, since they're no
 126      part in the collision.
 127
 128      |
 129      x|o
 130      x|o
 131      x
 132
 133   */
 134
 135   bool close_half_collide = false;
 136   bool distant_half_collide = false;
 137   bool full_collide = false;
 138
 139   int i = 0, j = 0;
 140   while (i < ups.size () && j < dps.size ())
 141     {
 142       if (abs (ups[i] - dps[j]) == 1)
 143         {
 144           merge_possible = false;
 145           if (ups[i] > dps[j])
 146             close_half_collide = true;
 147           else
 148             distant_half_collide = true;
 149         }
 150       else if (ups[i] == dps[j])
 151         full_collide = true;
 152       else if (ups[i] > dps[0] && ups[i] < dps.top ())
 153         merge_possible = false;
 154       else if (dps[j] > ups[0] && dps[j] < ups.top ())
 155         merge_possible = false;
 156
 157       if (ups[i] < dps[j])
 158         i++;
 159       else if (ups[i] > dps[j])
 160         j++;
 161       else
 162         {
 163           i++;
 164           j++;
 165         }
 166     }
 167
 168   full_collide = full_collide || (close_half_collide
 169                                   && distant_half_collide);
 170
 171   Drul_array<Real> center_note_shifts;
 172   center_note_shifts[LEFT] = 0.0;
 173   center_note_shifts[RIGHT] = 0.0;
 174
 175   Real shift_amount = 1;
 176
 177   bool touch = (ups[0] >= dps.top ());
 178   if (touch)
 179     shift_amount *= -1;
 180
 181   /* For full collisions, the right hand head may obscure dots, so
 182      make sure the dotted heads go to the right.  */
 183   bool stem_to_stem = false;
 184   if (full_collide)
 185     if (Rhythmic_head::dot_count (nu) > Rhythmic_head::dot_count (nd))
 186       shift_amount = 1;
 187     else if (Rhythmic_head::dot_count (nu) < Rhythmic_head::dot_count (nd))
 188       stem_to_stem = true;
 189
 190   if (merge_possible)
 191     {
 192       shift_amount = 0;
 193
 194       /* If possible, don't wipe any heads. Else, wipe shortest head,
 195          or head with smallest amount of dots.  Note: when merging
 196          different heads, dots on the smaller one disappear. */
 197       Grob *wipe_ball = 0;
 198       Grob *dot_wipe_head = nu;
 199
 200       if (upball_type == dnball_type)
 201         {
 202           if (Rhythmic_head::dot_count (nd) < Rhythmic_head::dot_count (nu))
 203             {
 204               wipe_ball = nd;
 205               dot_wipe_head = nd;
 206             }
 207           else if (Rhythmic_head::dot_count (nd) > Rhythmic_head::dot_count (nu))
 208             {
 209               dot_wipe_head = nu;
 210               wipe_ball = nu;
 211             }
 212           else
 213             {
 214               dot_wipe_head = nu;
 215             }
 216         }
 217       else if (dnball_type > upball_type)
 218         {
 219           wipe_ball = nd;
 220           dot_wipe_head = nd;
 221         }
 222       else if (dnball_type < upball_type)
 223         {
 224           wipe_ball = nu;
 225           dot_wipe_head = nu;
 226         }
 227
 228       if (dot_wipe_head)
 229         {
 230           if (Grob *d = unsmob_grob (dot_wipe_head->get_property ("dot")))
 231             d->suicide ();
 232         }
 233
 234       if (wipe_ball && wipe_ball->is_live ())
 235         {
 236           wipe_ball->set_property ("transparent", SCM_BOOL_T);
 237           wipe_ball->set_property ("stencil", SCM_EOL);
 238         }
 239     }
 240   /* TODO: these numbers are magic; should devise a set of grob props
 241      to tune this behavior.  */
 242   else if (stem_to_stem)
 243     shift_amount = -abs (shift_amount) * 0.65;
 244   else if (close_half_collide && !touch)
 245     shift_amount *= 0.52;
 246   else if (distant_half_collide && !touch)
 247     shift_amount *= 0.4;
 248   else if (distant_half_collide || close_half_collide || full_collide)
 249     shift_amount *= 0.5;
 250
 251   /* we're meshing.  */
 252   else if (Rhythmic_head::dot_count (nu) || Rhythmic_head::dot_count (nd))
 253     shift_amount *= 0.1;
 254   else
 255     shift_amount *= 0.17;
 256
 257   /* For full or close half collisions, the right hand head may
 258      obscure dots.  Move dots to the right.  */
 259   if (abs (shift_amount) > 1e-6
 260       && Rhythmic_head::dot_count (nd) > Rhythmic_head::dot_count (nu)
 261       && (full_collide || close_half_collide))
 262     {
 263       Grob *d = unsmob_grob (nd->get_property ("dot"));
 264       Grob *parent = d->get_parent (X_AXIS);
 265
 266       /*
 267         FIXME:
 268
 269         |
 270         x . o
 271         |
 272
 273
 274         the . is put right of o which is erroneous o force-shifted
 275         far to the right.
 276       */
 277       if (Dot_column::has_interface (parent))
 278         Side_position_interface::add_support (parent, nu);
 279     }
 280
 281   Direction d = UP;
 282   do
 283     {
 284       for (int i = 0; i < clash_groups[d].size (); i++)
 285         (*offsets)[d][i] += d * shift_amount;
 286     }
 287   while ((flip (&d)) != UP);
 288 }
 289
 290 void
 291 Note_collision_interface::do_shifts (Grob *me)
 292 {
 293   Drul_array<Link_array<Grob> > cg = get_clash_groups (me);
 294
 295   SCM autos (automatic_shift (me, cg));
 296   SCM hand (forced_shift (me));
 297
 298   Direction d = UP;
 299   Real wid = 0.0;
 300   do
 301     {
 302       if (cg[d].size ())
 303         {
 304           Grob *h = cg[d][0];
 305           wid = Note_column::first_head (h)->extent (h, X_AXIS).length ();
 306         }
 307     }
 308   while (flip (&d) != UP);
 309
 310   Link_array<Grob> done;
 311   Real left_most = 1e6;
 312
 313   Array<Real> amounts;
 314   for (; scm_is_pair (hand); hand = scm_cdr (hand))
 315     {
 316       Grob *s = unsmob_grob (scm_caar (hand));
 317       Real amount = scm_to_double (scm_cdar (hand)) * wid;
 318
 319       done.push (s);
 320       amounts.push (amount);
 321       if (amount < left_most)
 322         left_most = amount;
 323     }
 324   for (; scm_is_pair (autos); autos = scm_cdr (autos))
 325     {
 326       Grob *s = unsmob_grob (scm_caar (autos));
 327       Real amount = scm_to_double (scm_cdar (autos)) * wid;
 328
 329       if (!done.find (s))
 330         {
 331           done.push (s);
 332           amounts.push (amount);
 333           if (amount < left_most)
 334             left_most = amount;
 335         }
 336     }
 337
 338   for (int i = 0; i < amounts.size (); i++)
 339     {
 340       done[i]->translate_axis (amounts[i] - left_most, X_AXIS);
 341     }
 342 }
 343
 344 Drul_array < Link_array<Grob>
 345 > Note_collision_interface::get_clash_groups (Grob *me)
 346 {
 347   Drul_array<Link_array<Grob> > clash_groups;
 348
 349   SCM s = me->get_property ("elements");
 350   for (; scm_is_pair (s); s = scm_cdr (s))
 351     {
 352       SCM car = scm_car (s);
 353
 354       Grob *se = unsmob_grob (car);
 355       if (Note_column::has_interface (se))
 356         clash_groups[Note_column::dir (se)].push (se);
 357     }
 358
 359   Direction d = UP;
 360   do
 361     {
 362       Link_array<Grob> &clashes (clash_groups[d]);
 363       clashes.sort (Note_column::shift_compare);
 364     }
 365   while ((flip (&d)) != UP);
 366
 367   return clash_groups;
 368 }
 369
 370 /** This complicated routine moves note columns around horizontally to
 371     ensure that notes don't clash.
 372
 373     This should be put into Scheme.
 374 */
 375 SCM
 376 Note_collision_interface::automatic_shift (Grob *me,
 377                                            Drul_array < Link_array<Grob>
 378                                            > clash_groups)
 379 {
 380   Drul_array < Array<int> > shifts;
 381   SCM tups = SCM_EOL;
 382
 383   Direction d = UP;
 384   do
 385     {
 386       Array<int> &shift (shifts[d]);
 387       Link_array<Grob> &clashes (clash_groups[d]);
 388
 389       for (int i = 0; i < clashes.size (); i++)
 390         {
 391           SCM sh
 392             = clashes[i]->get_property ("horizontal-shift");
 393
 394           if (scm_is_number (sh))
 395             shift.push (scm_to_int (sh));
 396           else
 397             shift.push (0);
 398         }
 399
 400       for (int i = 1; i < shift.size (); i++)
 401         {
 402           if (shift[i - 1] == shift[i])
 403             {
 404               clashes[0]->warning (_ ("ignoring too many clashing note columns"));
 405               return tups;
 406             }
 407         }
 408     }
 409   while ((flip (&d)) != UP);
 410
 411   Drul_array<Array<Slice> > extents;
 412   Drul_array<Array<Real> > offsets;
 413   d = UP;
 414   do
 415     {
 416       for (int i = 0; i < clash_groups[d].size (); i++)
 417         {
 418           Slice s (Note_column::head_positions_interval (clash_groups[d][i]));
 419           s[LEFT]--;
 420           s[RIGHT]++;
 421           extents[d].push (s);
 422           offsets[d].push (d * 0.5 * i);
 423         }
 424     }
 425   while ((flip (&d)) != UP);
 426
 427   /*
 428     do horizontal shifts of each direction
 429
 430     |
 431     x||
 432     x||
 433     x|
 434   */
 435
 436   do
 437     {
 438       for (int i = 1; i < clash_groups[d].size (); i++)
 439         {
 440           Slice prev = extents[d][i - 1];
 441           prev.intersect (extents[d][i]);
 442           if (prev.length () > 0
 443               || (extents[-d].size () && d * (extents[d][i][-d] - extents[-d][0][d]) < 0))
 444             for (int j = i; j < clash_groups[d].size (); j++)
 445               offsets[d][j] += d * 0.5;
 446         }
 447     }
 448   while ((flip (&d)) != UP);
 449
 450   /*
 451     Check if chords are meshing
 452   */
 453
 454   check_meshing_chords (me, &offsets, extents, clash_groups);
 455
 456   do
 457     {
 458       for (int i = 0; i < clash_groups[d].size (); i++)
 459         tups = scm_cons (scm_cons (clash_groups[d][i]->self_scm (),
 460                                    scm_make_real (offsets[d][i])),
 461                          tups);
 462     }
 463   while (flip (&d) != UP);
 464
 465   return tups;
 466 }
 467
 468 SCM
 469 Note_collision_interface::forced_shift (Grob *me)
 470 {
 471   SCM tups = SCM_EOL;
 472
 473   SCM s = me->get_property ("elements");
 474   for (; scm_is_pair (s); s = scm_cdr (s))
 475     {
 476       Grob *se = unsmob_grob (scm_car (s));
 477
 478       SCM force = se->get_property ("force-hshift");
 479       if (scm_is_number (force))
 480         {
 481           tups = scm_cons (scm_cons (se->self_scm (), force),
 482                            tups);
 483         }
 484     }
 485   return tups;
 486 }
 487
 488 void
 489 Note_collision_interface::add_column (Grob *me, Grob *ncol)
 490 {
 491   ncol->add_offset_callback (Note_collision_interface::force_shift_callback_proc, X_AXIS);
 492   Axis_group_interface::add_element (me, ncol);
 493   me->add_dependency (ncol);
 494 }
 495
 496 ADD_INTERFACE (Note_collision_interface, "note-collision-interface",
 497                "An object that handles collisions between notes with different stem "
 498                "directions and horizontal shifts. Most of the interesting properties "
 499                "are to be set in @ref{note-column-interface}: these are "
 500                "@code{force-hshift} and @code{horizontal-shift}.",
 501
 502                "merge-differently-dotted merge-differently-headed positioning-done");