lily/note-spacing.cc

   1 /*
   2   note-spacing.cc -- implement Note_spacing
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2001--2003  Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9
  10 #include "paper-column.hh"
  11 #include "item.hh"
  12 #include "moment.hh"
  13 #include "note-spacing.hh"
  14 #include "grob.hh"
  15 #include "note-column.hh"
  16 #include "warn.hh"
  17 #include "stem.hh"
  18 #include "separation-item.hh"
  19 #include "staff-spacing.hh"
  20 #include "accidental-placement.hh"
  21 #include "paper-def.hh"
  22
  23 void
  24 Note_spacing::get_spacing (Grob *me, Item* right_col,
  25                            Real base_space, Real increment, Real *space, Real *fixed)
  26 {
  27
  28   Drul_array<SCM> props(me->get_grob_property ("left-items"),
  29                         me->get_grob_property ("right-items"));
  30   Direction d = LEFT;
  31   Direction col_dir =  right_col->break_status_dir ();
  32   Drul_array<Interval> extents;
  33
  34   Interval left_head_wid;
  35   do
  36     {
  37       for (SCM  s = props[d]; gh_pair_p (s); s = gh_cdr (s))
  38         {
  39           Item * it= dynamic_cast<Item*> (unsmob_grob (gh_car(s)));
  40
  41           if (d == RIGHT && it->break_status_dir () != col_dir)
  42             {
  43               it = it -> find_prebroken_piece (col_dir);
  44
  45             }
  46           /*
  47             some kind of mismatch, eg. a note column, that is behind a
  48             linebreak.
  49            */
  50           if (!it)
  51             continue;
  52
  53           Item *it_col = it->get_column ();
  54           if (d == RIGHT && right_col != it_col)
  55             continue;
  56
  57           if (Separation_item::has_interface (it))
  58             {
  59               extents[d].unite (Separation_item::width (it));
  60               continue;
  61             }
  62
  63           if (d == LEFT)
  64             {
  65               SCM r = it->get_grob_property ("rest");
  66               Grob * g = unsmob_grob (r);
  67               if (!g)
  68                 g =  Note_column::first_head (it);
  69
  70               /*
  71                 Ugh. If Stem is switched off, we don't know what the
  72                 first note head will be.
  73                */
  74               if (g)
  75                 left_head_wid = g->extent(it_col, X_AXIS);
  76             }
  77
  78           extents[d].unite (it->extent (it_col, X_AXIS));
  79           if (d == RIGHT)
  80             {
  81               Grob * accs = Note_column::accidentals (it);
  82               if (!accs)
  83                 accs = Note_column::accidentals (it->get_parent (X_AXIS));
  84
  85               if (accs)
  86                 {
  87                   Interval v =
  88                     Accidental_placement::get_relevant_accidental_extent (accs, it_col, me);
  89
  90                   extents[d].unite (v);
  91                 }
  92             }
  93         }
  94
  95       if (extents[d].empty_b ())
  96         extents[d] = Interval (0,0);
  97     }
  98   while (flip (&d) != LEFT);
  99
 100
 101   /*
 102     We look at the width of the note head, since smaller heads get less space
 103     eg. a quarter rest gets almost 0.5 ss less horizontal space than a note.
 104
 105     What is sticking out of the note head (eg. a flag), doesn't get
 106     the full amount of space.
 107
 108     FIXED also includes the left part of the right object.
 109   */
 110   *fixed =
 111     (left_head_wid.empty_b () ? increment :
 112      /*
 113        Size of the head:
 114       */
 115      (left_head_wid[RIGHT]+
 116
 117       /*
 118        What's sticking out of the head, eg. a flag:
 119       */
 120       (extents[LEFT][RIGHT] - left_head_wid[RIGHT])/2))
 121
 122     /*
 123       What is sticking out of the right note:
 124      */
 125     + (extents[RIGHT].empty_b() ?  0.0 : - extents[RIGHT][LEFT] / 2);
 126
 127   /*
 128     We don't do complicated stuff: (base_space - increment) is the
 129     normal amount of white, which also determines the amount of
 130     stretch. Upon (extreme) stretching, notes with accidentals should
 131     stretch as much as notes without accidentals.
 132    */
 133   *space = (base_space - increment) + *fixed ;
 134
 135   if (Item::breakable_b (right_col)
 136       || right_col->original_)
 137     {
 138       /*
 139         This is for the situation
 140
 141         rest | 3/4 (eol)
 142
 143        */
 144       *space += -extents[RIGHT][LEFT];
 145       *fixed += -extents[RIGHT][LEFT];
 146     }
 147
 148   stem_dir_correction (me, right_col, increment, space, fixed);
 149 }
 150
 151 Item *
 152 Note_spacing::left_column (Grob *me)
 153 {
 154   if (!me->live())
 155     return 0;
 156
 157   return dynamic_cast<Item*> (me)->get_column ();
 158 }
 159
 160 /*
 161   Compute the column of the right-items.  This is a big function,
 162 since RIGHT-ITEMS may span more columns (eg. if a clef if inserted,
 163 this will add a new columns to RIGHT-ITEMS. Here we look at the
 164 columns, and return the left-most. If there are multiple columns, we
 165 prune RIGHT-ITEMS.
 166
 167  */
 168 Item *
 169 Note_spacing::right_column (Grob*me)
 170 {
 171   if (!me->live())
 172     return 0;
 173
 174   SCM right = me->get_grob_property ("right-items");
 175   Item *mincol = 0;
 176   int min_rank = INT_MAX;
 177   bool prune = false;
 178   for (SCM s = right ; gh_pair_p (s) ; s = gh_cdr (s))
 179     {
 180       Item * ri = unsmob_item (gh_car (s));
 181
 182       Item * col = ri->get_column ();
 183       int rank = Paper_column::get_rank (col);
 184
 185       if (rank < min_rank)
 186         {
 187           min_rank = rank;
 188           if (mincol)
 189             prune = true;
 190
 191           mincol = col;
 192         }
 193     }
 194
 195   if (prune)
 196     {
 197       // I'm a lazy bum. We could do this in-place.
 198       SCM newright  = SCM_EOL;
 199       for (SCM s = right ; gh_pair_p (s) ; s =gh_cdr (s))
 200         {
 201           if (unsmob_item (gh_car (s))->get_column () == mincol)
 202             newright = gh_cons (gh_car (s), newright);
 203         }
 204
 205       me->set_grob_property ("right-items", newright);
 206     }
 207
 208   if (!mincol)
 209     {
 210       /*
 211       int r = Paper_column::get_rank (dynamic_cast<Item*>(me)->get_column ());
 212       programming_error (_f("Spacing wish column %d has no right item.", r));
 213       */
 214
 215       return 0;
 216     }
 217
 218   return mincol;
 219 }
 220
 221 /**
 222    Correct for optical illusions. See [Wanske] p. 138. The combination
 223    up-stem + down-stem should get extra space, the combination
 224    down-stem + up-stem less.
 225
 226    TODO: have to check wether the stems are in the same staff.
 227
 228 */
 229 void
 230 Note_spacing::stem_dir_correction (Grob*me, Item * rcolumn,
 231                                    Real increment,
 232                                    Real * space, Real *fixed)
 233 {
 234   Drul_array<Direction> stem_dirs(CENTER,CENTER);
 235   Drul_array<Interval> stem_posns;
 236   Drul_array<Interval> head_posns;
 237   Drul_array<SCM> props(me->get_grob_property ("left-items"),
 238                         me->get_grob_property ("right-items"));
 239
 240   Drul_array<Grob*> beams_drul(0,0);
 241   Drul_array<Grob*> stems_drul(0,0);
 242
 243   stem_dirs[LEFT] = stem_dirs[RIGHT] = CENTER;
 244   Interval intersect;
 245   Interval bar_xextent;
 246   Interval bar_yextent;
 247
 248   bool correct_stem_dirs = true;
 249   Direction d = LEFT;
 250   bool acc_right = false;
 251
 252   do
 253     {
 254       for (SCM  s = props[d]; gh_pair_p (s); s = gh_cdr (s))
 255         {
 256           Item * it= dynamic_cast<Item*> (unsmob_grob (gh_car(s)));
 257
 258           if (d == RIGHT)
 259             acc_right = acc_right || Note_column::accidentals (it);
 260
 261           Grob *stem = Note_column::get_stem (it);
 262
 263           if (!stem || !stem->live ())
 264             {
 265               if (d == RIGHT && Separation_item::has_interface (it))
 266                 {
 267                   if (it->get_column () != rcolumn)
 268                     {
 269                       it = it->find_prebroken_piece (rcolumn->break_status_dir ());
 270                     }
 271
 272                   Grob *last = Staff_spacing::extremal_break_aligned_grob (it, LEFT, &bar_xextent);
 273
 274                   if (last)
 275                     bar_yextent = Staff_spacing::bar_y_positions (last);
 276
 277                   break;
 278                 }
 279
 280               return ;
 281             }
 282
 283           if(Stem::invisible_b (stem))
 284             {
 285               correct_stem_dirs = false;
 286               continue;
 287             }
 288
 289           stems_drul[d] = stem;
 290           beams_drul[d] = Stem::get_beam (stem);
 291
 292
 293           Direction sd = Stem::get_direction (stem);
 294           if (stem_dirs[d] && stem_dirs[d] != sd)
 295             {
 296               correct_stem_dirs = false;
 297               continue;
 298             }
 299           stem_dirs[d] = sd;
 300
 301           /*
 302             Correction doesn't seem appropriate  when there is a large flag
 303             hanging from the note.
 304            */
 305           if (d == LEFT
 306               && Stem::duration_log (stem) > 2  && !Stem::get_beam (stem))
 307             {
 308               correct_stem_dirs = false;
 309             }
 310
 311           Interval hp  = Stem::head_positions (stem);
 312           Real chord_start = hp[sd];
 313           Real stem_end = Stem::stem_end_position (stem);
 314
 315           stem_posns[d] = Interval(chord_start<?stem_end, chord_start>? stem_end);
 316           head_posns[d].unite (hp);
 317         }
 318     }
 319   while (flip (&d) != LEFT);
 320
 321
 322   /*
 323     don't correct if accidentals are sticking out of the right side.
 324   */
 325   if (acc_right)
 326     return ;
 327
 328   Real correction = 0.0;
 329
 330   if (!bar_yextent.empty_b())
 331     {
 332       stem_dirs[RIGHT] = - stem_dirs[LEFT];
 333       stem_posns[RIGHT] = bar_yextent;
 334     }
 335
 336   if (correct_stem_dirs && stem_dirs[LEFT] *stem_dirs[RIGHT] == -1)
 337     {
 338       if (beams_drul[LEFT] && beams_drul[LEFT] == beams_drul[RIGHT])
 339         {
 340
 341           /*
 342             this is a knee: maximal correction.
 343           */
 344           Real note_head_width = increment;
 345           Grob * st = stems_drul[RIGHT];
 346           Grob * head = st ? Stem::support_head (st)  : 0;
 347
 348           Interval head_extent;
 349           if (head)
 350             {
 351               head_extent = head->extent (rcolumn, X_AXIS);
 352
 353               if (!head_extent.empty_b())
 354                 note_head_width = head_extent[RIGHT];
 355
 356               if (st)
 357                 {
 358                   Real thick = gh_scm2double (st->get_grob_property ("thickness"))
 359                     * st->get_paper ()->get_realvar (ly_symbol2scm ("linethickness"));
 360
 361                   note_head_width -= thick;
 362                 }
 363             }
 364
 365           correction = note_head_width* stem_dirs[LEFT];
 366           correction *= gh_scm2double (me->get_grob_property ("knee-spacing-correction"));
 367           *fixed += correction;
 368         }
 369       else
 370         {
 371           intersect = stem_posns[LEFT];
 372           intersect.intersect(stem_posns[RIGHT]);
 373           correct_stem_dirs = correct_stem_dirs && !intersect.empty_b ();
 374
 375           if (correct_stem_dirs)
 376             {
 377               correction =abs (intersect.length ());
 378
 379
 380               /*
 381                 Ugh. 7 is hardcoded.
 382               */
 383               correction = (correction/7) <? 1.0;
 384               correction *= stem_dirs[LEFT] ;
 385               correction *=
 386                 gh_scm2double (me->get_grob_property ("stem-spacing-correction"));
 387             }
 388
 389           if (!bar_yextent.empty_b())
 390             {
 391               correction *= 0.5;
 392             }
 393         }
 394     }
 395   else if (correct_stem_dirs && stem_dirs[LEFT] *stem_dirs[RIGHT] == UP)
 396     {
 397       /*
 398         Correct for the following situation:
 399
 400          X      X
 401         |      |
 402         |      |
 403         |   X  |
 404         |  |   |
 405         ========
 406
 407            ^ move the center one to the left.
 408
 409
 410         this effect seems to be much more subtle than the
 411         stem-direction stuff (why?), and also does not scale with the
 412         difference in stem length.
 413
 414        */
 415
 416
 417       Interval hp = head_posns[LEFT];
 418       hp.intersect  (head_posns[RIGHT]);
 419       if (!hp.empty_b())
 420         return ;
 421
 422       Direction lowest =
 423         (head_posns[LEFT][DOWN] > head_posns[RIGHT][UP]) ? RIGHT : LEFT;
 424
 425       Real delta = head_posns[-lowest][DOWN] - head_posns[lowest][UP] ;
 426       Real corr = gh_scm2double (me->get_grob_property ("stem-spacing-correction"));
 427       corr =  (delta <= 1) ? 0.0 : 0.25;
 428
 429       correction=  -lowest * corr ;
 430     }
 431
 432   *space += correction;
 433
 434 #if 0
 435   /* there used to be a correction for bar_xextent() here, but
 436      it's unclear what that was good for ?
 437   */
 438 #endif
 439
 440 }
 441
 442
 443
 444
 445 ADD_INTERFACE (Note_spacing,"note-spacing-interface",
 446   "",
 447   "left-items right-items stem-spacing-correction knee-spacing-correction");
 448