lily/auto-beam-engraver.cc

   1 /*
   2   auto-beam-engraver.cc --  implement Auto_beam_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999--2003 Jan Nieuwenhuizen <janneke@gnu.org>
   7
   8  */
   9
  10 #include "beaming.hh"
  11 #include "event.hh"
  12 #include "beam.hh"
  13 #include "stem.hh"
  14 #include "warn.hh"
  15 #include "engraver-group-engraver.hh"
  16 #include "bar-line.hh"
  17 #include "rest.hh"
  18 #include "engraver.hh"
  19 #include "item.hh"
  20 #include "spanner.hh"
  21 #include "duration.hh"
  22
  23 /*
  24   TODO: figure what to do in grace?
  25
  26   TODO: documentme.
  27  */
  28 class Auto_beam_engraver : public Engraver
  29 {
  30   TRANSLATOR_DECLARATIONS(Auto_beam_engraver);
  31 protected:
  32   virtual void stop_translation_timestep ();
  33   virtual void start_translation_timestep ();
  34   virtual void finalize ();
  35   virtual void acknowledge_grob (Grob_info);
  36   virtual void process_acknowledged_grobs ();
  37
  38 private:
  39   bool test_moment (Direction, Moment);
  40   void consider_begin (Moment);
  41   void consider_end (Moment);
  42   Spanner* create_beam ();
  43   void begin_beam ();
  44   void end_beam ();
  45   void junk_beam ();
  46   bool same_grace_state_b (Grob* e);
  47   void typeset_beam ();
  48
  49   /*
  50     shortest_mom is the shortest note in the beam.
  51    */
  52   Moment shortest_mom_;
  53   Spanner *finished_beam_;
  54   Link_array<Item>* stems_;
  55
  56
  57   int count_;
  58   Moment last_add_mom_;
  59   /*
  60     Projected ending of the  beam we're working on.
  61    */
  62   Moment extend_mom_;
  63   Moment beam_start_moment_;
  64   Moment beam_start_location_;
  65
  66   bool subdivide_beams_;
  67   Moment beat_length_;
  68
  69   // We act as if beam were created, and start a grouping anyway.
  70   Beaming_info_list*grouping_;
  71   SCM beam_settings_ ;          // ugh. should protect ?
  72
  73   Beaming_info_list*finished_grouping_;
  74 };
  75
  76
  77
  78 Auto_beam_engraver::Auto_beam_engraver ()
  79 {
  80   count_ = 0;
  81   stems_ = 0;
  82   shortest_mom_ = Moment (Rational (1, 8));
  83   finished_beam_ = 0;
  84   finished_grouping_ = 0;
  85   grouping_ = 0;
  86   beam_settings_ = SCM_EOL;
  87 }
  88
  89 /*
  90   Determine end moment for auto beaming (or begin moment, but mostly
  91   0==anywhere) In order of increasing priority:
  92
  93   i.   begin anywhere, end at every beat
  94   ii.  end   *    <num> <den>
  95   iii. end <type> <num> <den>
  96
  97   iv.  end   *      *     *
  98   v.   end <type>   *     *
  99
 100
 101   Rationale:
 102
 103   [to be defined in config file]
 104   i.   easy catch-all rule
 105   ii.  exceptions for time signature
 106   iii. exceptions for time signature, for specific duration type
 107
 108   [user override]
 109   iv.  generic override
 110   v.   override for specific duration type
 111
 112 */
 113 bool
 114 Auto_beam_engraver::test_moment (Direction dir, Moment test_mom)
 115 {
 116   Moment now = now_mom();
 117   if (dir == START
 118       && now.grace_part_)
 119     {
 120       return false;
 121     }
 122
 123   SCM wild = scm_list_n (ly_symbol2scm ("*"), ly_symbol2scm ("*"), SCM_UNDEFINED);
 124   SCM function;
 125   if (dir == START)
 126     function = scm_list_n (ly_symbol2scm ("begin"), SCM_UNDEFINED);
 127   else
 128     function = scm_list_n (ly_symbol2scm ("end"), SCM_UNDEFINED);
 129
 130   Moment one_beat = *unsmob_moment (get_property ("beatLength"));
 131   int num = int ((*unsmob_moment (get_property ("measureLength")) / one_beat).main_part_);
 132   int den = one_beat.den ();
 133   SCM time = scm_list_n (scm_int2num (num), scm_int2num (den), SCM_UNDEFINED);
 134
 135   SCM type = scm_list_n (scm_int2num (test_mom.num ()),
 136                       scm_int2num (test_mom.den ()), SCM_UNDEFINED);
 137
 138   SCM settings = get_property ("autoBeamSettings");
 139
 140   /* first guess */
 141
 142   /* begin beam at any position
 143  (and fallback for end) */
 144   Moment moment (0);
 145
 146   /* end beam at end of beat */
 147   if (dir == STOP)
 148     {
 149       SCM beat (get_property ("beatLength"));
 150
 151       if (unsmob_moment (beat))
 152         moment = *unsmob_moment (beat);
 153     }
 154
 155   /* second guess: property generic time exception */
 156   SCM m = gh_assoc (gh_append3 (function, wild, time), settings);
 157
 158   if (m != SCM_BOOL_F && unsmob_moment (ly_cdr (m)))
 159     moment = * unsmob_moment (ly_cdr (m));
 160
 161   /* third guess: property time exception, specific for duration type */
 162   m = gh_assoc (gh_append3 (function, type, time), settings);
 163   if (m != SCM_BOOL_F && unsmob_moment (ly_cdr (m)))
 164     moment = * unsmob_moment (ly_cdr (m));
 165
 166   /* fourth guess [user override]: property plain generic */
 167   m = gh_assoc (gh_append3 (function, wild, wild), settings);
 168   if (m != SCM_BOOL_F && unsmob_moment (ly_cdr (m)))
 169     moment = * unsmob_moment (ly_cdr (m));
 170
 171   /* fifth guess [user override]: property plain, specific for duration type */
 172   m = gh_assoc (gh_append3 (function, type, wild), settings);
 173   if (m != SCM_BOOL_F && unsmob_moment (ly_cdr (m)))
 174     moment = * unsmob_moment (ly_cdr (m));
 175
 176   Rational r;
 177   if (moment.to_bool ())
 178     {
 179       /* Ugh? measurePosition can be negative, when \partial
 180          We may have to fix this elsewhere (timing translator)
 181         r = unsmob_moment (get_property ("measurePosition"))->mod_rat (moment);
 182       */
 183       Moment pos = * unsmob_moment (get_property ("measurePosition"));
 184       if (pos < Moment (0))
 185         {
 186           Moment length = * unsmob_moment (get_property ("measureLength"));
 187           pos = length - pos;
 188         }
 189       r = pos.main_part_.mod_rat (moment.main_part_);
 190     }
 191   else
 192     {
 193       if (dir == START)
 194         /* if undefined, starting is ok */
 195         r = 0;
 196       else
 197         /* but ending is not */
 198         r = 1;
 199     }
 200
 201   return !r;
 202 }
 203
 204 void
 205 Auto_beam_engraver::consider_begin (Moment test_mom)
 206 {
 207   bool on = to_boolean (get_property ("autoBeaming"));
 208   if (!stems_ && on)
 209     {
 210       bool b = test_moment (START, test_mom);
 211       if (b)
 212         begin_beam ();
 213     }
 214 }
 215
 216 void
 217 Auto_beam_engraver::consider_end (Moment test_mom)
 218 {
 219   if (stems_)
 220     {
 221       /* Allow already started autobeam to end:
 222          don't check for autoBeaming */
 223       bool b = test_moment (STOP, test_mom);
 224       if (b)
 225         end_beam ();
 226     }
 227 }
 228
 229 Spanner*
 230 Auto_beam_engraver::create_beam ()
 231 {
 232   if (to_boolean (get_property ("skipTypesetting")))
 233     {
 234      return 0;
 235     }
 236
 237   Spanner* beam = new Spanner (beam_settings_);
 238   for (int i = 0; i < stems_->size (); i++)
 239     {
 240       /*
 241         watch out for stem tremolos and abbreviation beams
 242        */
 243       if (Stem::get_beam ((*stems_)[i]))
 244         {
 245           scm_gc_unprotect_object (beam->self_scm ());
 246           return 0;
 247         }
 248       Beam::add_stem (beam, (*stems_)[i]);
 249     }
 250
 251   announce_grob(beam, SCM_EOL);
 252
 253   return beam;
 254 }
 255
 256 void
 257 Auto_beam_engraver::begin_beam ()
 258 {
 259   assert (!stems_);
 260   stems_ = new Link_array<Item>;
 261   assert (!grouping_);
 262   grouping_ = new Beaming_info_list;
 263   beam_settings_ = get_property ("Beam");
 264
 265   beam_start_moment_ = now_mom ();
 266   beam_start_location_ = *unsmob_moment (get_property ("measurePosition"));
 267   subdivide_beams_ = gh_scm2bool(get_property("subdivideBeams"));
 268   beat_length_ = *unsmob_moment (get_property ("beatLength"));
 269 }
 270
 271
 272 void
 273 Auto_beam_engraver::junk_beam ()
 274 {
 275   assert (stems_);
 276
 277   delete stems_;
 278   stems_ = 0;
 279   delete grouping_;
 280   grouping_ = 0;
 281   beam_settings_ = SCM_EOL;
 282
 283   shortest_mom_ = Moment (Rational (1, 8));
 284 }
 285
 286 void
 287 Auto_beam_engraver::end_beam ()
 288 {
 289   if (stems_->size () < 2)
 290     {
 291       junk_beam ();
 292     }
 293   else
 294
 295     {
 296       finished_beam_ = create_beam ();
 297       if (finished_beam_)
 298         finished_grouping_ = grouping_;
 299       delete stems_;
 300       stems_ = 0;
 301       grouping_ = 0;
 302       beam_settings_ = SCM_EOL;
 303     }
 304
 305   shortest_mom_ = Moment (Rational (1, 8));
 306 }
 307
 308 void
 309 Auto_beam_engraver::typeset_beam ()
 310 {
 311   if (finished_beam_)
 312     {
 313       finished_grouping_->beamify(beat_length_, subdivide_beams_);
 314       Beam::set_beaming (finished_beam_, finished_grouping_);
 315       typeset_grob (finished_beam_);
 316       finished_beam_ = 0;
 317
 318       delete finished_grouping_;
 319       finished_grouping_= 0;
 320     }
 321 }
 322
 323 void
 324 Auto_beam_engraver::start_translation_timestep ()
 325 {
 326   count_ = 0;
 327   /*
 328     don't beam over skips
 329    */
 330   if (stems_)
 331     {
 332       Moment now = now_mom ();
 333       if (extend_mom_ < now)
 334         {
 335           end_beam ();
 336         }
 337     }
 338 }
 339
 340 void
 341 Auto_beam_engraver::stop_translation_timestep ()
 342 {
 343   typeset_beam ();
 344 }
 345
 346 void
 347 Auto_beam_engraver::finalize ()
 348 {
 349   /* finished beams may be typeset */
 350   typeset_beam ();
 351   /* but unfinished may need another announce/acknowledge pass */
 352   if (stems_)
 353     junk_beam ();
 354 }
 355
 356
 357 void
 358 Auto_beam_engraver::acknowledge_grob (Grob_info info)
 359 {
 360   if (stems_)
 361     {
 362       if (Beam::has_interface (info.grob_))
 363         {
 364           end_beam ();
 365         }
 366       else if (Bar_line::has_interface (info.grob_))
 367         {
 368           end_beam ();
 369         }
 370       else if (Rest::has_interface (info.grob_))
 371         {
 372           end_beam ();
 373         }
 374     }
 375
 376   if (Stem::has_interface (info.grob_))
 377     {
 378       Item* stem = dynamic_cast<Item *> (info.grob_);
 379       Music* m = info.music_cause ();
 380       if (!m->is_mus_type ("rhythmic-event"))
 381         {
 382           programming_error ("Stem must have rhythmic structure");
 383           return;
 384         }
 385
 386       /*
 387         Don't (start) auto-beam over empty stems; skips or rests
 388         */
 389       if (!Stem::head_count (stem))
 390         {
 391           if (stems_)
 392             end_beam ();
 393           return;
 394         }
 395
 396       if (Stem::get_beam (stem))
 397         {
 398           if (stems_)
 399             junk_beam ();
 400           return ;
 401         }
 402
 403       int durlog  = unsmob_duration (m->get_mus_property ("duration"))->duration_log ();
 404
 405       if (durlog <= 2)
 406         {
 407           if (stems_)
 408             end_beam ();
 409           return;
 410         }
 411
 412
 413       /*
 414         ignore grace notes.
 415        */
 416       if (bool (beam_start_location_.grace_part_) != bool (now_mom ().grace_part_))
 417         return ;
 418
 419
 420       Moment dur = unsmob_duration (m->get_mus_property ("duration"))->get_length ();
 421       /* FIXME:
 422
 423         This comment has been here since long:
 424
 425            if shortest duration would change
 426             consider ending and beginning beam first.
 427
 428         but the code didn't match: */
 429 #if 1
 430       consider_end (dur);
 431       consider_begin (dur);
 432
 433       if (dur < shortest_mom_)
 434         shortest_mom_ = dur;
 435 #else
 436       /* I very much suspect that we wanted: */
 437
 438       consider_end (shortest_mom_);
 439       if (dur < shortest_mom_)
 440         {
 441           shortest_mom_ = dur;
 442           consider_end (shortest_mom_);
 443         }
 444       consider_begin (shortest_mom_);
 445 #endif
 446
 447       if (!stems_)
 448         return;
 449
 450       Moment now = now_mom ();
 451
 452       grouping_->add_stem (now - beam_start_moment_ + beam_start_location_,
 453                              durlog - 2);
 454       stems_->push (stem);
 455       last_add_mom_ = now;
 456       extend_mom_ = (extend_mom_ >? now) + m->get_length ();
 457     }
 458 }
 459
 460 void
 461 Auto_beam_engraver::process_acknowledged_grobs ()
 462 {
 463   if (!count_)
 464     {
 465       consider_end (shortest_mom_);
 466       consider_begin (shortest_mom_);
 467     }
 468   else if (count_ > 1)
 469     {
 470       if (stems_)
 471         {
 472           Moment now = now_mom ();
 473           if ((extend_mom_ < now)
 474               || ((extend_mom_ == now) && (last_add_mom_ != now)))
 475             {
 476               end_beam ();
 477             }
 478           else if (!stems_->size ())
 479             {
 480               junk_beam ();
 481             }
 482         }
 483     }
 484
 485   /*
 486     count_++ ->
 487
 488         auto-beam-engraver.cc:459: warning: value computed is not used (gcc: 2.96) */
 489   count_ = count_ + 1;
 490 }
 491
 492 ENTER_DESCRIPTION (Auto_beam_engraver,
 493 /* descr */       "Generate beams based on measure characteristics and observed "
 494 "Stems.  Uses beatLength, measureLength and measurePosition to decide "
 495 "when to start and stop a beam.  Overriding beaming is done through "
 496 "@ref{Stem_engraver} properties stemLeftBeamCount and "
 497 "stemRightBeamCount. "
 498 ,
 499 /* creats*/       "Beam",
 500 /* accepts */     "",
 501 /* acks  */      "stem-interface rest-interface beam-interface bar-line-interface",
 502 /* reads */       "autoBeaming autoBeamSettings beatLength subdivideBeams",
 503 /* write */       "");