2 beam-engraver.cc -- implement Beam_engraver
4 source file of the GNU LilyPond music typesetter
6 (c) 1998--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
14 #include "score-engraver.hh"
16 #include "drul-array.hh"
20 #include "duration.hh"
22 #include "translator.icc"
24 class Beam_engraver : public Engraver
29 Spanner *finished_beam_;
31 Music *prev_start_ev_;
35 Beaming_info_list *beam_info_;
36 Beaming_info_list *finished_beam_info_;
38 /// location within measure where beam started.
39 Moment beam_start_location_;
41 /// moment (global time) where beam started.
42 Moment beam_start_mom_;
44 bool subdivide_beams_;
48 void set_melisma (bool);
50 Moment last_stem_added_at_;
51 PRECOMPUTED_VIRTUAL void stop_translation_timestep ();
52 PRECOMPUTED_VIRTUAL void start_translation_timestep ();
53 virtual void finalize ();
55 virtual void acknowledge_grob (Grob_info);
56 virtual bool try_music (Music *);
57 PRECOMPUTED_VIRTUAL void process_music ();
59 virtual bool valid_start_point ();
60 virtual bool valid_end_point ();
63 TRANSLATOR_DECLARATIONS (Beam_engraver);
67 Hmm. this isn't necessary, since grace beams and normal beams are
71 Beam_engraver::valid_start_point ()
73 Moment n = now_mom ();
75 return n.grace_part_ == Rational (0);
79 Beam_engraver::valid_end_point ()
81 return valid_start_point ();
84 Beam_engraver::Beam_engraver ()
88 finished_beam_info_ = 0;
96 Beam_engraver::try_music (Music *m)
98 if (m->is_mus_type ("beam-event"))
100 Direction d = to_dir (m->get_property ("span-direction"));
101 if (d == START && !valid_start_point ())
103 if (d == STOP && !valid_end_point ())
120 Beam_engraver::set_melisma (bool ml)
122 SCM b = get_property ("autoBeaming");
124 context ()->set_property ("beamMelismaBusy", ml ? SCM_BOOL_T : SCM_BOOL_F);
128 Beam_engraver::process_music ()
130 if (beam_ && !to_boolean (get_property ("allowBeamBreak")))
132 get_score_engraver ()->forbid_breaks ();
139 start_ev_->origin ()->warning (_ ("already have a beam"));
144 prev_start_ev_ = start_ev_;
145 beam_ = make_spanner ("Beam", start_ev_->self_scm ());
146 Moment mp (robust_scm2moment (get_property ("measurePosition"), Moment (0)));
148 beam_start_location_ = mp;
149 beam_start_mom_ = now_mom ();
151 beam_info_ = new Beaming_info_list;
153 /* urg, must copy to Auto_beam_engraver too */
158 Beam_engraver::typeset_beam ()
162 finished_beam_info_->beamify (beat_length_, subdivide_beams_);
163 Beam::set_beaming (finished_beam_, finished_beam_info_);
165 delete finished_beam_info_;
166 finished_beam_info_ = 0;
172 Beam_engraver::start_translation_timestep ()
180 subdivide_beams_ = to_boolean (get_property ("subdivideBeams"));
181 beat_length_ = robust_scm2moment (get_property ("beatLength"), Moment (1, 4));
186 Beam_engraver::stop_translation_timestep ()
191 finished_beam_ = beam_;
192 finished_beam_info_ = beam_info_;
203 Beam_engraver::finalize ()
208 prev_start_ev_->origin ()->warning (_ ("unterminated beam"));
211 we don't typeset it, (we used to, but it was commented
212 out. Reason unknown) */
219 Beam_engraver::acknowledge_grob (Grob_info info)
223 if (Rest::has_interface (info.grob ()))
225 info.grob ()->add_offset_callback (Beam::rest_collision_callback_proc, Y_AXIS);
227 else if (Stem::has_interface (info.grob ()))
229 Moment now = now_mom ();
231 if (!valid_start_point ())
234 Item *stem = dynamic_cast<Item *> (info.grob ());
235 if (Stem::get_beam (stem))
238 Music *m = info.music_cause ();
239 if (!m->is_mus_type ("rhythmic-event"))
241 String s = _ ("stem must have Rhythmic structure");
242 if (info.music_cause ())
243 info.music_cause ()->origin ()->warning (s);
250 last_stem_added_at_ = now;
251 int durlog = unsmob_duration (m->get_property ("duration"))->duration_log ();
254 m->origin ()->warning (_ ("stem doesn't fit in beam"));
255 prev_start_ev_->origin ()->warning (_ ("beam was started here"));
259 [r4 c8] can just as well be modern notation.
263 stem->set_property ("duration-log",
264 scm_int2num (durlog));
265 Moment stem_location = now - beam_start_mom_ + beam_start_location_;
266 beam_info_->add_stem (stem_location,
268 Beam::add_stem (beam_, stem);
273 ADD_TRANSLATOR (Beam_engraver,
274 /* descr */ "Handles Beam events by engraving Beams. If omitted, then notes will be "
275 "printed with flags instead of beams.",
277 /* accepts */ "beam-event",
278 /* acks */ "stem-interface rest-interface",
279 /* reads */ "beamMelismaBusy beatLength subdivideBeams",
282 class Grace_beam_engraver : public Beam_engraver
285 TRANSLATOR_DECLARATIONS (Grace_beam_engraver);
288 virtual bool valid_start_point ();
289 virtual bool valid_end_point ();
292 Grace_beam_engraver::Grace_beam_engraver ()
297 Grace_beam_engraver::valid_start_point ()
299 Moment n = now_mom ();
301 return n.grace_part_ != Rational (0);
305 Grace_beam_engraver::valid_end_point ()
307 return beam_ && valid_start_point ();
310 ADD_TRANSLATOR (Grace_beam_engraver,
311 /* descr */ "Handles Beam events by engraving Beams. If omitted, then notes will "
312 "be printed with flags instead of beams. Only engraves beams when we "
313 " are at grace points in time. ",
315 /* accepts */ "beam-event",
316 /* acks */ "stem-interface rest-interface",
317 /* reads */ "beamMelismaBusy beatLength allowBeamBreak subdivideBeams",