lily/beam-engraver.cc

   1 /*
   2   beam-engraver.cc --  implement Beam_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1998--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9 #include "engraver-group-engraver.hh"
  10 #include "engraver.hh"
  11 #include "event.hh"
  12 #include "beam.hh"
  13 #include "stem.hh"
  14 #include "warn.hh"
  15 #include "beaming.hh"
  16 #include "score-engraver.hh"
  17 #include "rest.hh"
  18 #include "drul-array.hh"
  19 #include "item.hh"
  20 #include "spanner.hh"
  21
  22 class Beam_engraver : public Engraver
  23 {
  24 protected:
  25   Drul_array<Music*> evs_drul_;
  26
  27   Spanner *finished_beam_;
  28   Spanner *beam_;
  29   Music * prev_start_ev_;
  30
  31   Music * now_stop_ev_;
  32
  33   Beaming_info_list * beam_info_;
  34   Beaming_info_list * finished_beam_info_;
  35
  36   /// location  within measure where beam started.
  37   Moment beam_start_location_;
  38
  39   /// moment (global time) where beam started.
  40   Moment beam_start_mom_;
  41
  42   bool subdivide_beams_;
  43   Moment beat_length_;
  44
  45   void typeset_beam ();
  46   void set_melisma (bool);
  47
  48   Moment last_stem_added_at_;
  49     virtual void stop_translation_timestep ();
  50   virtual void start_translation_timestep ();
  51   virtual void finalize ();
  52
  53   virtual void acknowledge_grob (Grob_info);
  54   virtual bool try_music (Music*);
  55   virtual void process_music ();
  56
  57   virtual bool valid_start_moment();
  58   virtual bool valid_end_moment ();
  59
  60 public:
  61   TRANSLATOR_DECLARATIONS(  Beam_engraver );
  62 };
  63
  64
  65 /*
  66   Hmm. this isn't necessary, since grace beams and normal beams are
  67   always nested.
  68  */
  69 bool
  70 Beam_engraver::valid_start_moment()
  71 {
  72   Moment n = now_mom ();
  73
  74   return n.grace_part_ == Rational (0);
  75 }
  76
  77 bool
  78 Beam_engraver::valid_end_moment()
  79 {
  80   return last_stem_added_at_.grace_part_ == Rational(0);
  81 }
  82
  83
  84 Beam_engraver::Beam_engraver ()
  85 {
  86   beam_ = 0;
  87   finished_beam_ =0;
  88   finished_beam_info_=0;
  89   beam_info_ =0;
  90   now_stop_ev_ = 0;
  91   evs_drul_[LEFT] = evs_drul_[RIGHT] =0;
  92   prev_start_ev_ =0;
  93 }
  94
  95 bool
  96 Beam_engraver::try_music (Music *m)
  97 {
  98   if (m->is_mus_type ("abort-event"))
  99     {
 100       evs_drul_[START] = 0;
 101       evs_drul_[STOP] = 0;
 102       if (beam_)
 103         beam_->suicide ();
 104       beam_ = 0;
 105     }
 106   else if (m->is_mus_type ("beam-event"))
 107     {
 108       Direction d = to_dir (m->get_mus_property ("span-direction"));
 109
 110       if (d == STOP && !valid_end_moment())
 111         return false;
 112
 113       if (d == START && !valid_start_moment ())
 114         return false;
 115
 116       if (d == STOP)
 117         {
 118           SCM m = get_property ("automaticMelismata");
 119           SCM b = get_property ("autoBeaming");
 120           if (to_boolean (m) && !to_boolean (b))
 121             {
 122               set_melisma (false);
 123             }
 124         }
 125
 126       evs_drul_[d ] = m;
 127       return true;
 128     }
 129   else if (m->is_mus_type ("new-beam-event"))
 130     {
 131       Direction d = to_dir (m->get_mus_property ("span-direction"));
 132       if (d == START && !valid_start_moment ())
 133         return false;
 134       if (d == STOP && !valid_end_moment ())
 135         return false;
 136
 137       if (d == START)
 138         evs_drul_[d] = m;
 139       else if (d==STOP)
 140         now_stop_ev_ = m;
 141
 142       return true;
 143     }
 144   return false;
 145 }
 146
 147 void
 148 Beam_engraver::set_melisma (bool m)
 149 {
 150   daddy_trans_->set_property ("beamMelismaBusy", m ? SCM_BOOL_T :SCM_BOOL_F);
 151 }
 152
 153 void
 154 Beam_engraver::process_music ()
 155 {
 156   if (evs_drul_[STOP])
 157     {
 158       prev_start_ev_ =0;
 159       finished_beam_ = beam_;
 160       finished_beam_info_ = beam_info_;
 161
 162       beam_info_ =0;
 163       beam_ = 0;
 164     }
 165
 166   if (beam_)
 167     {
 168       top_engraver ()->forbid_breaks ();
 169     }
 170   if (evs_drul_[START])
 171     {
 172       if (beam_)
 173         {
 174           evs_drul_[START]->origin ()->warning (_ ("already have a beam"));
 175           return;
 176         }
 177
 178       prev_start_ev_ = evs_drul_[START];
 179       beam_ = new Spanner (get_property ("Beam"));
 180       SCM smp = get_property ("measurePosition");
 181       Moment mp = (unsmob_moment (smp)) ? *unsmob_moment (smp) : Moment (0);
 182
 183       beam_start_location_ = mp;
 184       beam_start_mom_ = now_mom ();
 185
 186       beam_info_ = new Beaming_info_list;
 187
 188       /* urg, must copy to Auto_beam_engraver too */
 189
 190       announce_grob(beam_, evs_drul_[START]->self_scm());
 191     }
 192
 193 }
 194
 195
 196 void
 197 Beam_engraver::typeset_beam ()
 198 {
 199   if (finished_beam_)
 200     {
 201       finished_beam_info_->beamify(beat_length_, subdivide_beams_);
 202       Beam::set_beaming (finished_beam_, finished_beam_info_);
 203       typeset_grob (finished_beam_);
 204       delete finished_beam_info_;
 205       finished_beam_info_ =0;
 206       finished_beam_ = 0;
 207     }
 208 }
 209
 210 void
 211 Beam_engraver::start_translation_timestep ()
 212 {
 213   evs_drul_ [START] =0;
 214   evs_drul_[STOP] = 0;
 215
 216   if (beam_)
 217     {
 218       SCM m = get_property ("automaticMelismata");
 219       SCM b = get_property ("autoBeaming");
 220       if (to_boolean (m) && !to_boolean (b))
 221         {
 222           set_melisma (true);
 223         }
 224       subdivide_beams_ = to_boolean(get_property("subdivideBeams"));
 225       beat_length_ = *unsmob_moment (get_property ("beatLength"));
 226     }
 227 }
 228
 229 void
 230 Beam_engraver::stop_translation_timestep ()
 231 {
 232   typeset_beam ();
 233   if (now_stop_ev_ )
 234     {
 235       finished_beam_ = beam_;
 236       finished_beam_info_ = beam_info_;
 237
 238       now_stop_ev_ = 0;
 239       beam_ = 0;
 240       beam_info_ = 0;
 241       typeset_beam();
 242     }
 243 }
 244
 245 void
 246 Beam_engraver::finalize ()
 247 {
 248   typeset_beam ();
 249   if (beam_)
 250     {
 251       prev_start_ev_->origin ()->warning (_ ("unterminated beam"));
 252
 253       /*
 254         we don't typeset it, (we used to, but it was commented
 255         out. Reason unknown) */
 256       beam_->suicide ();
 257       delete beam_info_;
 258     }
 259 }
 260
 261 void
 262 Beam_engraver::acknowledge_grob (Grob_info info)
 263 {
 264   if (beam_)
 265     {
 266       if (Rest::has_interface (info.grob_))
 267         {
 268           info.grob_->add_offset_callback (Beam::rest_collision_callback_proc, Y_AXIS);
 269         }
 270       else if (Stem::has_interface (info.grob_))
 271         {
 272           Moment now = now_mom();
 273
 274           if (!valid_start_moment ())
 275             return ;
 276
 277           Item *stem = dynamic_cast<Item*> (info.grob_);
 278           if (Stem::get_beam (stem))
 279             return;
 280
 281           Music* m = info.music_cause();
 282           if (!m->is_mus_type ("rhythmic-event"))
 283             {
 284               String s = _ ("stem must have Rhythmic structure");
 285               if (info.music_cause ())
 286                 info.music_cause ()->origin ()->warning (s);
 287               else
 288                 ::warning (s);
 289
 290               return;
 291             }
 292
 293
 294           last_stem_added_at_ = now;
 295           int durlog  = unsmob_duration (m->get_mus_property ("duration"))-> duration_log ();
 296           if (durlog <= 2)
 297             {
 298               m->origin ()->warning (_ ("stem doesn't fit in beam"));
 299               prev_start_ev_->origin ()->warning (_ ("beam was started here"));
 300               /*
 301                 don't return, since
 302
 303                 [r4 c8] can just as well be modern notation.
 304               */
 305             }
 306
 307           stem->set_grob_property ("duration-log",
 308                                     scm_int2num (durlog));
 309           Moment stem_location = now - beam_start_mom_ + beam_start_location_;
 310           beam_info_->add_stem (stem_location,
 311  (durlog- 2) >? 0);
 312           Beam::add_stem (beam_, stem);
 313         }
 314     }
 315 }
 316
 317
 318
 319
 320
 321 ENTER_DESCRIPTION(Beam_engraver,
 322 /* descr */       "Handles Beam events by engraving Beams.    If omitted, then notes will be "
 323 "printed with flags instead of beams.",
 324 /* creats*/       "Beam",
 325 /* accepts */     "beam-event new-beam-event abort-event",
 326 /* acks  */      "stem-interface rest-interface",
 327 /* reads */       "beamMelismaBusy beatLength subdivideBeams",
 328 /* write */       "");
 329
 330
 331 class Grace_beam_engraver : public Beam_engraver
 332 {
 333 public:
 334   TRANSLATOR_DECLARATIONS(Grace_beam_engraver);
 335
 336 protected:
 337   virtual bool valid_start_moment();
 338   virtual bool valid_end_moment ();
 339 };
 340
 341 Grace_beam_engraver::Grace_beam_engraver()
 342 {
 343 }
 344
 345 bool
 346 Grace_beam_engraver::valid_start_moment()
 347 {
 348   Moment n = now_mom ();
 349
 350   return n.grace_part_ != Rational (0);
 351 }
 352
 353
 354 bool
 355 Grace_beam_engraver::valid_end_moment ()
 356 {
 357   return beam_ && last_stem_added_at_.grace_part_ != Rational(0);
 358 }
 359
 360
 361
 362 ENTER_DESCRIPTION(Grace_beam_engraver,
 363 /* descr */       "Handles Beam events by engraving Beams.  If omitted, then notes will "
 364 "be printed with flags instead of beams. Only engraves beams when we "
 365 " are at grace points in time. "
 366 ,
 367 /* creats*/       "Beam",
 368 /* accepts */     "beam-event abort-event new-beam-event",
 369 /* acks  */      "stem-interface rest-interface",
 370 /* reads */       "beamMelismaBusy beatLength subdivideBeams",
 371 /* write */       "");
 372