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--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  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 #include "context.hh"
  22
  23 class Beam_engraver : public Engraver
  24 {
  25 protected:
  26   Music * start_ev_;
  27
  28   Spanner *finished_beam_;
  29   Spanner *beam_;
  30   Music * prev_start_ev_;
  31
  32   Music * now_stop_ev_;
  33
  34   Beaming_info_list * beam_info_;
  35   Beaming_info_list * finished_beam_info_;
  36
  37   /// location  within measure where beam started.
  38   Moment beam_start_location_;
  39
  40   /// moment (global time) where beam started.
  41   Moment beam_start_mom_;
  42
  43   bool subdivide_beams_;
  44   Moment beat_length_;
  45
  46   void typeset_beam ();
  47   void set_melisma (bool);
  48
  49   Moment last_stem_added_at_;
  50   virtual void stop_translation_timestep ();
  51   virtual void start_translation_timestep ();
  52   virtual void finalize ();
  53
  54   virtual void acknowledge_grob (Grob_info);
  55   virtual bool try_music (Music*);
  56   virtual void process_music ();
  57
  58   virtual bool valid_start_point ();
  59   virtual bool valid_end_point ();
  60
  61 public:
  62   TRANSLATOR_DECLARATIONS (Beam_engraver);
  63 };
  64
  65
  66 /*
  67   Hmm. this isn't necessary, since grace beams and normal beams are
  68   always nested.
  69  */
  70 bool
  71 Beam_engraver::valid_start_point ()
  72 {
  73   Moment n = now_mom ();
  74
  75   return n.grace_part_ == Rational (0);
  76 }
  77
  78 bool
  79 Beam_engraver::valid_end_point ()
  80 {
  81   return valid_start_point ();
  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   start_ev_ = 0;
  92   prev_start_ev_ =0;
  93 }
  94
  95 bool
  96 Beam_engraver::try_music (Music *m)
  97 {
  98   if (m->is_mus_type ("beam-event"))
  99     {
 100       Direction d = to_dir (m->get_property ("span-direction"));
 101       if (d == START && !valid_start_point ())
 102         return false;
 103       if (d == STOP && !valid_end_point ())
 104         return false;
 105
 106       if (d == START)
 107         {
 108           start_ev_ = m;
 109         }
 110       else if (d==STOP)
 111         {
 112           now_stop_ev_ = m;
 113         }
 114       return true;
 115     }
 116   return false;
 117 }
 118
 119 void
 120 Beam_engraver::set_melisma (bool ml)
 121 {
 122   SCM b = get_property ("autoBeaming");
 123   if (!to_boolean (b))
 124     context ()->set_property ("beamMelismaBusy", ml ? SCM_BOOL_T :SCM_BOOL_F);
 125 }
 126
 127 void
 128 Beam_engraver::process_music ()
 129 {
 130   if (beam_ && !to_boolean (get_property ("allowBeamBreak")))
 131     {
 132       get_score_engraver ()->forbid_breaks ();
 133     }
 134
 135   if (start_ev_)
 136     {
 137       if (beam_)
 138         {
 139           start_ev_->origin ()->warning (_ ("already have a beam"));
 140           return;
 141         }
 142
 143       set_melisma (true);
 144       prev_start_ev_ = start_ev_;
 145       beam_ = make_spanner ("Beam", start_ev_->self_scm ());
 146       SCM smp = get_property ("measurePosition");
 147       Moment mp = (unsmob_moment (smp)) ? *unsmob_moment (smp) : Moment (0);
 148
 149       beam_start_location_ = mp;
 150       beam_start_mom_ = now_mom ();
 151
 152       beam_info_ = new Beaming_info_list;
 153
 154       /* urg, must copy to Auto_beam_engraver too */
 155     }
 156
 157 }
 158
 159
 160 void
 161 Beam_engraver::typeset_beam ()
 162 {
 163   if (finished_beam_)
 164     {
 165       finished_beam_info_->beamify (beat_length_, subdivide_beams_);
 166       Beam::set_beaming (finished_beam_, finished_beam_info_);
 167
 168       delete finished_beam_info_;
 169       finished_beam_info_ =0;
 170       finished_beam_ = 0;
 171     }
 172 }
 173
 174 void
 175 Beam_engraver::start_translation_timestep ()
 176 {
 177   start_ev_ = 0;
 178
 179   if (beam_)
 180     {
 181       set_melisma (true);
 182
 183       subdivide_beams_ = to_boolean (get_property ("subdivideBeams"));
 184       beat_length_ = *unsmob_moment (get_property ("beatLength"));
 185     }
 186 }
 187
 188 void
 189 Beam_engraver::stop_translation_timestep ()
 190 {
 191   typeset_beam ();
 192   if (now_stop_ev_ )
 193     {
 194       finished_beam_ = beam_;
 195       finished_beam_info_ = beam_info_;
 196
 197       now_stop_ev_ = 0;
 198       beam_ = 0;
 199       beam_info_ = 0;
 200       typeset_beam ();
 201       set_melisma (false);
 202     }
 203 }
 204
 205 void
 206 Beam_engraver::finalize ()
 207 {
 208   typeset_beam ();
 209   if (beam_)
 210     {
 211       prev_start_ev_->origin ()->warning (_ ("unterminated beam"));
 212
 213       /*
 214         we don't typeset it, (we used to, but it was commented
 215         out. Reason unknown) */
 216       beam_->suicide ();
 217       delete beam_info_;
 218     }
 219 }
 220
 221 void
 222 Beam_engraver::acknowledge_grob (Grob_info info)
 223 {
 224   if (beam_)
 225     {
 226       if (Rest::has_interface (info.grob_))
 227         {
 228           info.grob_->add_offset_callback (Beam::rest_collision_callback_proc, Y_AXIS);
 229         }
 230       else if (Stem::has_interface (info.grob_))
 231         {
 232           Moment now = now_mom ();
 233
 234           if (!valid_start_point ())
 235             return ;
 236
 237           Item *stem = dynamic_cast<Item*> (info.grob_);
 238           if (Stem::get_beam (stem))
 239             return;
 240
 241           Music* m = info.music_cause ();
 242           if (!m->is_mus_type ("rhythmic-event"))
 243             {
 244               String s = _ ("stem must have Rhythmic structure");
 245               if (info.music_cause ())
 246                 info.music_cause ()->origin ()->warning (s);
 247               else
 248                 ::warning (s);
 249
 250               return;
 251             }
 252
 253
 254           last_stem_added_at_ = now;
 255           int durlog  = unsmob_duration (m->get_property ("duration"))-> duration_log ();
 256           if (durlog <= 2)
 257             {
 258               m->origin ()->warning (_ ("stem doesn't fit in beam"));
 259               prev_start_ev_->origin ()->warning (_ ("beam was started here"));
 260               /*
 261                 don't return, since
 262
 263                 [r4 c8] can just as well be modern notation.
 264               */
 265             }
 266
 267           stem->set_property ("duration-log",
 268                                     scm_int2num (durlog));
 269           Moment stem_location = now - beam_start_mom_ + beam_start_location_;
 270           beam_info_->add_stem (stem_location,
 271  (durlog- 2) >? 0);
 272           Beam::add_stem (beam_, stem);
 273         }
 274     }
 275 }
 276
 277
 278
 279
 280
 281 ENTER_DESCRIPTION (Beam_engraver,
 282 /* descr */       "Handles Beam events by engraving Beams.    If omitted, then notes will be "
 283 "printed with flags instead of beams.",
 284 /* creats*/       "Beam",
 285 /* accepts */     "beam-event",
 286 /* acks  */      "stem-interface rest-interface",
 287 /* reads */       "beamMelismaBusy beatLength subdivideBeams",
 288 /* write */       "");
 289
 290
 291 class Grace_beam_engraver : public Beam_engraver
 292 {
 293 public:
 294   TRANSLATOR_DECLARATIONS (Grace_beam_engraver);
 295
 296 protected:
 297   virtual bool valid_start_point ();
 298   virtual bool valid_end_point ();
 299 };
 300
 301 Grace_beam_engraver::Grace_beam_engraver ()
 302 {
 303 }
 304
 305 bool
 306 Grace_beam_engraver::valid_start_point ()
 307 {
 308   Moment n = now_mom ();
 309
 310   return n.grace_part_ != Rational (0);
 311 }
 312
 313
 314 bool
 315 Grace_beam_engraver::valid_end_point ()
 316 {
 317   return beam_ && valid_start_point ();
 318 }
 319
 320
 321
 322 ENTER_DESCRIPTION (Grace_beam_engraver,
 323 /* descr */       "Handles Beam events by engraving Beams.  If omitted, then notes will "
 324 "be printed with flags instead of beams. Only engraves beams when we "
 325 " are at grace points in time. "
 326 ,
 327 /* creats*/       "Beam",
 328 /* accepts */     "beam-event",
 329 /* acks  */      "stem-interface rest-interface",
 330 /* reads */       "beamMelismaBusy beatLength allowBeamBreak subdivideBeams",
 331 /* write */       "");
 332