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--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "beam.hh"
  10 #include "beaming-pattern.hh"
  11 #include "context.hh"
  12 #include "drul-array.hh"
  13 #include "duration.hh"
  14 #include "engraver.hh"
  15 #include "international.hh"
  16 #include "item.hh"
  17 #include "rest.hh"
  18 #include "spanner.hh"
  19 #include "stream-event.hh"
  20 #include "stem.hh"
  21 #include "warn.hh"
  22
  23 #include "translator.icc"
  24
  25 class Beam_engraver : public Engraver
  26 {
  27 public:
  28   DECLARE_ACKNOWLEDGER (stem);
  29   DECLARE_ACKNOWLEDGER (rest);
  30
  31 protected:
  32   Stream_event *start_ev_;
  33
  34   Spanner *finished_beam_;
  35   Spanner *beam_;
  36   Stream_event *prev_start_ev_;
  37
  38   Stream_event *stop_ev_;
  39
  40   Beaming_pattern *beam_info_;
  41   Beaming_pattern *finished_beam_info_;
  42
  43   /// location  within measure where beam started.
  44   Moment beam_start_location_;
  45
  46   /// moment (global time) where beam started.
  47   Moment beam_start_mom_;
  48
  49   Beaming_options beaming_options_;
  50   Beaming_options finished_beaming_options_;
  51
  52   void typeset_beam ();
  53   void set_melisma (bool);
  54
  55   Moment last_stem_added_at_;
  56   void stop_translation_timestep ();
  57   void start_translation_timestep ();
  58   virtual void finalize ();
  59
  60   void process_music ();
  61
  62   virtual bool valid_start_point ();
  63   virtual bool valid_end_point ();
  64
  65   DECLARE_TRANSLATOR_LISTENER (beam);
  66 public:
  67   TRANSLATOR_DECLARATIONS (Beam_engraver);
  68 };
  69
  70 /*
  71   Hmm. this isn't necessary, since grace beams and normal beams are
  72   always nested.
  73 */
  74 bool
  75 Beam_engraver::valid_start_point ()
  76 {
  77   Moment n = now_mom ();
  78
  79   return n.grace_part_ == Rational (0);
  80 }
  81
  82 bool
  83 Beam_engraver::valid_end_point ()
  84 {
  85   return valid_start_point ();
  86 }
  87
  88 Beam_engraver::Beam_engraver ()
  89 {
  90   beam_ = 0;
  91   finished_beam_ = 0;
  92   finished_beam_info_ = 0;
  93   beam_info_ = 0;
  94   stop_ev_ = 0;
  95   start_ev_ = 0;
  96   prev_start_ev_ = 0;
  97 }
  98
  99 IMPLEMENT_TRANSLATOR_LISTENER (Beam_engraver, beam);
 100 void
 101 Beam_engraver::listen_beam (Stream_event *ev)
 102 {
 103   Direction d = to_dir (ev->get_property ("span-direction"));
 104
 105   if (d == START && valid_start_point ())
 106     ASSIGN_EVENT_ONCE (start_ev_, ev);
 107   else if (d == STOP && valid_end_point ())
 108     ASSIGN_EVENT_ONCE (stop_ev_, ev);
 109 }
 110
 111 void
 112 Beam_engraver::set_melisma (bool ml)
 113 {
 114   SCM b = get_property ("autoBeaming");
 115   if (!to_boolean (b))
 116     context ()->set_property ("beamMelismaBusy", ml ? SCM_BOOL_T : SCM_BOOL_F);
 117 }
 118
 119 void
 120 Beam_engraver::process_music ()
 121 {
 122   if (start_ev_)
 123     {
 124       if (beam_)
 125         {
 126           start_ev_->origin ()->warning (_ ("already have a beam"));
 127           return;
 128         }
 129
 130       set_melisma (true);
 131       prev_start_ev_ = start_ev_;
 132       beam_ = make_spanner ("Beam", start_ev_->self_scm ());
 133       Moment mp (robust_scm2moment (get_property ("measurePosition"), Moment (0)));
 134
 135       beam_start_location_ = mp;
 136       beam_start_mom_ = now_mom ();
 137
 138       beaming_options_.from_context (context ());
 139       beam_info_ = new Beaming_pattern;
 140       /* urg, must copy to Auto_beam_engraver too */
 141     }
 142
 143   typeset_beam ();
 144   if (stop_ev_ && beam_)
 145     {
 146       announce_end_grob (beam_, stop_ev_->self_scm ());
 147
 148     }
 149 }
 150
 151 void
 152 Beam_engraver::typeset_beam ()
 153 {
 154   if (finished_beam_)
 155     {
 156       if (!finished_beam_->get_bound (RIGHT))
 157         finished_beam_->set_bound (RIGHT, finished_beam_->get_bound (LEFT));
 158
 159       finished_beam_info_->beamify (finished_beaming_options_);
 160       Beam::set_beaming (finished_beam_, finished_beam_info_);
 161
 162       delete finished_beam_info_;
 163       finished_beam_info_ = 0;
 164       finished_beam_ = 0;
 165     }
 166 }
 167
 168 void
 169 Beam_engraver::start_translation_timestep ()
 170 {
 171   start_ev_ = 0;
 172
 173   if (beam_)
 174     {
 175       set_melisma (true);
 176     }
 177 }
 178
 179 void
 180 Beam_engraver::stop_translation_timestep ()
 181 {
 182   if (stop_ev_)
 183     {
 184       finished_beam_ = beam_;
 185       finished_beam_info_ = beam_info_;
 186       finished_beaming_options_ = beaming_options_;
 187
 188       stop_ev_ = 0;
 189       beam_ = 0;
 190       beam_info_ = 0;
 191       typeset_beam ();
 192       set_melisma (false);
 193     }
 194 }
 195
 196 void
 197 Beam_engraver::finalize ()
 198 {
 199   typeset_beam ();
 200   if (beam_)
 201     {
 202       prev_start_ev_->origin ()->warning (_ ("unterminated beam"));
 203
 204       /*
 205         we don't typeset it, (we used to, but it was commented
 206         out. Reason unknown) */
 207       beam_->suicide ();
 208       delete beam_info_;
 209     }
 210 }
 211
 212 void
 213 Beam_engraver::acknowledge_rest (Grob_info info)
 214 {
 215   if (beam_
 216       && !scm_is_number (info.grob ()->get_property_data ("staff-position")))
 217     {
 218       chain_offset_callback (info.grob (),
 219                              Beam::rest_collision_callback_proc, Y_AXIS);
 220     }
 221 }
 222
 223
 224
 225 void
 226 Beam_engraver::acknowledge_stem (Grob_info info)
 227 {
 228   if (!beam_)
 229     return;
 230
 231   Moment now = now_mom ();
 232   if (!valid_start_point ())
 233     return;
 234
 235   Item *stem = dynamic_cast<Item *> (info.grob ());
 236   if (Stem::get_beam (stem))
 237     return;
 238
 239
 240
 241   Stream_event *ev = info.ultimate_event_cause ();
 242   if (!ev->in_event_class ("rhythmic-event"))
 243     {
 244       info.grob ()->warning (_ ("stem must have Rhythmic structure"));
 245       return;
 246     }
 247
 248   last_stem_added_at_ = now;
 249   int durlog = unsmob_duration (ev->get_property ("duration"))->duration_log ();
 250   if (durlog <= 2)
 251     {
 252       ev->origin ()->warning (_ ("stem does not fit in beam"));
 253       prev_start_ev_->origin ()->warning (_ ("beam was started here"));
 254       /*
 255         don't return, since
 256
 257         [r4 c8] can just as well be modern notation.
 258       */
 259     }
 260
 261   stem->set_property ("duration-log",
 262                       scm_from_int (durlog));
 263   Moment stem_location = now - beam_start_mom_ + beam_start_location_;
 264   beam_info_->add_stem (stem_location,
 265                         max (durlog- 2, 0),
 266                         Stem::is_invisible (stem));
 267   Beam::add_stem (beam_, stem);
 268 }
 269
 270 ADD_ACKNOWLEDGER (Beam_engraver, stem);
 271 ADD_ACKNOWLEDGER (Beam_engraver, rest);
 272
 273 ADD_TRANSLATOR (Beam_engraver,
 274                 /* doc */
 275                 "Handle @code{Beam} events by engraving beams.  If omitted,"
 276                 " then notes are printed with flags instead of beams.",
 277
 278                 /* create */
 279                 "Beam ",
 280
 281                 /* read */
 282                 "beamMelismaBusy "
 283                 "beatLength "
 284                 "subdivideBeams ",
 285
 286                 /* write */
 287                 "forbidBreak"
 288                 );
 289
 290 class Grace_beam_engraver : public Beam_engraver
 291 {
 292 public:
 293   TRANSLATOR_DECLARATIONS (Grace_beam_engraver);
 294
 295   DECLARE_TRANSLATOR_LISTENER (beam);
 296
 297 protected:
 298   virtual bool valid_start_point ();
 299   virtual bool valid_end_point ();
 300 };
 301
 302 Grace_beam_engraver::Grace_beam_engraver ()
 303 {
 304 }
 305
 306 bool
 307 Grace_beam_engraver::valid_start_point ()
 308 {
 309   Moment n = now_mom ();
 310
 311   return n.grace_part_ != Rational (0);
 312 }
 313
 314 bool
 315 Grace_beam_engraver::valid_end_point ()
 316 {
 317   return beam_ && valid_start_point ();
 318 }
 319
 320 /*
 321   Ugh, C&P code.
 322  */
 323 IMPLEMENT_TRANSLATOR_LISTENER (Grace_beam_engraver, beam);
 324 void
 325 Grace_beam_engraver::listen_beam (Stream_event *ev)
 326 {
 327   Direction d = to_dir (ev->get_property ("span-direction"));
 328
 329   if (d == START && valid_start_point ())
 330     start_ev_ = ev;
 331   else if (d == STOP && valid_end_point ())
 332     stop_ev_ = ev;
 333 }
 334
 335
 336 ADD_ACKNOWLEDGER (Grace_beam_engraver, stem);
 337 ADD_ACKNOWLEDGER (Grace_beam_engraver, rest);
 338
 339 ADD_TRANSLATOR (Grace_beam_engraver,
 340                 /* doc */
 341                 "Handle @code{Beam} events by engraving beams.  If omitted,"
 342                 " then notes are printed with flags instead of beams.  Only"
 343                 " engraves beams when we are at grace points in time.",
 344
 345                 /* create */
 346                 "Beam ",
 347
 348                 /* read */
 349                 "beamMelismaBusy "
 350                 "beatLength "
 351                 "subdivideBeams ",
 352
 353                 /* write */
 354                 ""
 355                 );
 356