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
27 DECLARE_ACKNOWLEDGER(stem);
28 DECLARE_ACKNOWLEDGER(rest);
32 Spanner *finished_beam_;
34 Music *prev_start_ev_;
38 Beaming_info_list *beam_info_;
39 Beaming_info_list *finished_beam_info_;
41 /// location within measure where beam started.
42 Moment beam_start_location_;
44 /// moment (global time) where beam started.
45 Moment beam_start_mom_;
47 bool subdivide_beams_;
51 void set_melisma (bool);
53 Moment last_stem_added_at_;
54 void stop_translation_timestep ();
55 void start_translation_timestep ();
56 virtual void finalize ();
58 virtual bool try_music (Music *);
59 void process_music ();
61 virtual bool valid_start_point ();
62 virtual bool valid_end_point ();
65 TRANSLATOR_DECLARATIONS (Beam_engraver);
69 Hmm. this isn't necessary, since grace beams and normal beams are
73 Beam_engraver::valid_start_point ()
75 Moment n = now_mom ();
77 return n.grace_part_ == Rational (0);
81 Beam_engraver::valid_end_point ()
83 return valid_start_point ();
86 Beam_engraver::Beam_engraver ()
90 finished_beam_info_ = 0;
98 Beam_engraver::try_music (Music *m)
100 if (m->is_mus_type ("beam-event"))
102 Direction d = to_dir (m->get_property ("span-direction"));
103 if (d == START && !valid_start_point ())
105 if (d == STOP && !valid_end_point ())
122 Beam_engraver::set_melisma (bool ml)
124 SCM b = get_property ("autoBeaming");
126 context ()->set_property ("beamMelismaBusy", ml ? SCM_BOOL_T : SCM_BOOL_F);
130 Beam_engraver::process_music ()
132 if (beam_ && !to_boolean (get_property ("allowBeamBreak")))
134 get_score_engraver ()->forbid_breaks ();
141 start_ev_->origin ()->warning (_ ("already have a beam"));
146 prev_start_ev_ = start_ev_;
147 beam_ = make_spanner ("Beam", start_ev_->self_scm ());
148 Moment mp (robust_scm2moment (get_property ("measurePosition"), Moment (0)));
150 beam_start_location_ = mp;
151 beam_start_mom_ = now_mom ();
153 beam_info_ = new Beaming_info_list;
155 /* urg, must copy to Auto_beam_engraver too */
160 Beam_engraver::typeset_beam ()
164 finished_beam_info_->beamify (beat_length_, subdivide_beams_);
165 Beam::set_beaming (finished_beam_, finished_beam_info_);
167 delete finished_beam_info_;
168 finished_beam_info_ = 0;
174 Beam_engraver::start_translation_timestep ()
182 subdivide_beams_ = to_boolean (get_property ("subdivideBeams"));
183 beat_length_ = robust_scm2moment (get_property ("beatLength"), Moment (1, 4));
188 Beam_engraver::stop_translation_timestep ()
193 finished_beam_ = beam_;
194 finished_beam_info_ = beam_info_;
205 Beam_engraver::finalize ()
210 prev_start_ev_->origin ()->warning (_ ("unterminated beam"));
213 we don't typeset it, (we used to, but it was commented
214 out. Reason unknown) */
221 Beam_engraver::acknowledge_rest (Grob_info info)
224 info.grob ()->add_offset_callback (Beam::rest_collision_callback_proc, Y_AXIS);
228 Beam_engraver::acknowledge_stem (Grob_info info)
232 Moment now = now_mom ();
234 if (!valid_start_point ())
237 Item *stem = dynamic_cast<Item *> (info.grob ());
238 if (Stem::get_beam (stem))
241 Music *m = info.music_cause ();
242 if (!m->is_mus_type ("rhythmic-event"))
244 String s = _ ("stem must have Rhythmic structure");
245 if (info.music_cause ())
246 info.music_cause ()->origin ()->warning (s);
253 last_stem_added_at_ = now;
254 int durlog = unsmob_duration (m->get_property ("duration"))->duration_log ();
257 m->origin ()->warning (_ ("stem doesn't fit in beam"));
258 prev_start_ev_->origin ()->warning (_ ("beam was started here"));
262 [r4 c8] can just as well be modern notation.
266 stem->set_property ("duration-log",
267 scm_int2num (durlog));
268 Moment stem_location = now - beam_start_mom_ + beam_start_location_;
269 beam_info_->add_stem (stem_location,
271 Beam::add_stem (beam_, stem);
275 ADD_ACKNOWLEDGER(Beam_engraver, stem);
276 ADD_ACKNOWLEDGER(Beam_engraver, rest);
278 ADD_TRANSLATOR (Beam_engraver,
279 /* descr */ "Handles Beam events by engraving Beams. If omitted, then notes will be "
280 "printed with flags instead of beams.",
282 /* accepts */ "beam-event",
283 /* reads */ "beamMelismaBusy beatLength subdivideBeams",
286 class Grace_beam_engraver : public Beam_engraver
289 TRANSLATOR_DECLARATIONS (Grace_beam_engraver);
292 virtual bool valid_start_point ();
293 virtual bool valid_end_point ();
296 Grace_beam_engraver::Grace_beam_engraver ()
301 Grace_beam_engraver::valid_start_point ()
303 Moment n = now_mom ();
305 return n.grace_part_ != Rational (0);
309 Grace_beam_engraver::valid_end_point ()
311 return beam_ && valid_start_point ();
314 ADD_ACKNOWLEDGER(Grace_beam_engraver, stem);
315 ADD_ACKNOWLEDGER(Grace_beam_engraver, rest);
316 ADD_TRANSLATOR (Grace_beam_engraver,
317 /* descr */ "Handles Beam events by engraving Beams. If omitted, then notes will "
318 "be printed with flags instead of beams. Only engraves beams when we "
319 " are at grace points in time. ",
321 /* accepts */ "beam-event",
322 /* reads */ "beamMelismaBusy beatLength allowBeamBreak subdivideBeams",