2 beam-engraver.cc -- implement Beam_engraver
4 source file of the GNU LilyPond music typesetter
6 (c) 1998--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
12 #include "drul-array.hh"
13 #include "duration.hh"
14 #include "engraver.hh"
15 #include "international.hh"
18 #include "score-engraver.hh"
23 #include "translator.icc"
25 class Beam_engraver : public Engraver
28 DECLARE_ACKNOWLEDGER (stem);
29 DECLARE_ACKNOWLEDGER (rest);
33 Spanner *finished_beam_;
35 Music *prev_start_ev_;
39 Beaming_info_list *beam_info_;
40 Beaming_info_list *finished_beam_info_;
42 /// location within measure where beam started.
43 Moment beam_start_location_;
45 /// moment (global time) where beam started.
46 Moment beam_start_mom_;
48 bool subdivide_beams_;
52 void set_melisma (bool);
54 Moment last_stem_added_at_;
55 void stop_translation_timestep ();
56 void start_translation_timestep ();
57 virtual void finalize ();
59 virtual bool try_music (Music *);
60 void process_music ();
62 virtual bool valid_start_point ();
63 virtual bool valid_end_point ();
66 TRANSLATOR_DECLARATIONS (Beam_engraver);
70 Hmm. this isn't necessary, since grace beams and normal beams are
74 Beam_engraver::valid_start_point ()
76 Moment n = now_mom ();
78 return n.grace_part_ == Rational (0);
82 Beam_engraver::valid_end_point ()
84 return valid_start_point ();
87 Beam_engraver::Beam_engraver ()
91 finished_beam_info_ = 0;
99 Beam_engraver::try_music (Music *m)
101 if (m->is_mus_type ("beam-event"))
103 Direction d = to_dir (m->get_property ("span-direction"));
104 if (d == START && !valid_start_point ())
106 if (d == STOP && !valid_end_point ())
119 Beam_engraver::set_melisma (bool ml)
121 SCM b = get_property ("autoBeaming");
123 context ()->set_property ("beamMelismaBusy", ml ? SCM_BOOL_T : SCM_BOOL_F);
127 Beam_engraver::process_music ()
129 if (beam_ && !to_boolean (get_property ("allowBeamBreak")))
130 get_score_engraver ()->forbid_breaks ();
136 start_ev_->origin ()->warning (_ ("already have a beam"));
141 prev_start_ev_ = start_ev_;
142 beam_ = make_spanner ("Beam", start_ev_->self_scm ());
143 Moment mp (robust_scm2moment (get_property ("measurePosition"), Moment (0)));
145 beam_start_location_ = mp;
146 beam_start_mom_ = now_mom ();
148 beam_info_ = new Beaming_info_list;
150 /* urg, must copy to Auto_beam_engraver too */
155 Beam_engraver::typeset_beam ()
159 finished_beam_info_->beamify (beat_length_, subdivide_beams_);
160 Beam::set_beaming (finished_beam_, finished_beam_info_);
162 delete finished_beam_info_;
163 finished_beam_info_ = 0;
169 Beam_engraver::start_translation_timestep ()
177 subdivide_beams_ = to_boolean (get_property ("subdivideBeams"));
178 beat_length_ = robust_scm2moment (get_property ("beatLength"), Moment (1, 4));
183 Beam_engraver::stop_translation_timestep ()
188 finished_beam_ = beam_;
189 finished_beam_info_ = beam_info_;
200 Beam_engraver::finalize ()
205 prev_start_ev_->origin ()->warning (_ ("unterminated beam"));
208 we don't typeset it, (we used to, but it was commented
209 out. Reason unknown) */
216 Beam_engraver::acknowledge_rest (Grob_info info)
220 chain_offset_callback (info.grob(),
221 Beam::rest_collision_callback_proc, Y_AXIS);
228 Beam_engraver::acknowledge_stem (Grob_info info)
233 Moment now = now_mom ();
234 if (!valid_start_point ())
237 Item *stem = dynamic_cast<Item *> (info.grob ());
238 if (Stem::get_beam (stem))
243 Music *m = info.ultimate_music_cause ();
244 if (!m->is_mus_type ("rhythmic-event"))
246 string s = _ ("stem must have Rhythmic structure");
247 if (info.music_cause ())
248 info.music_cause ()->origin ()->warning (s);
255 last_stem_added_at_ = now;
256 int durlog = unsmob_duration (m->get_property ("duration"))->duration_log ();
259 m->origin ()->warning (_ ("stem doesn't fit in beam"));
260 prev_start_ev_->origin ()->warning (_ ("beam was started here"));
264 [r4 c8] can just as well be modern notation.
268 stem->set_property ("duration-log",
269 scm_from_int (durlog));
270 Moment stem_location = now - beam_start_mom_ + beam_start_location_;
271 beam_info_->add_stem (stem_location,
273 Beam::add_stem (beam_, stem);
276 ADD_ACKNOWLEDGER (Beam_engraver, stem);
277 ADD_ACKNOWLEDGER (Beam_engraver, rest);
279 ADD_TRANSLATOR (Beam_engraver,
280 /* doc */ "Handles Beam events by engraving Beams. If omitted, then notes will be "
281 "printed with flags instead of beams.",
283 /* accept */ "beam-event",
284 /* read */ "beamMelismaBusy beatLength subdivideBeams",
287 class Grace_beam_engraver : public Beam_engraver
290 TRANSLATOR_DECLARATIONS (Grace_beam_engraver);
293 virtual bool valid_start_point ();
294 virtual bool valid_end_point ();
297 Grace_beam_engraver::Grace_beam_engraver ()
302 Grace_beam_engraver::valid_start_point ()
304 Moment n = now_mom ();
306 return n.grace_part_ != Rational (0);
310 Grace_beam_engraver::valid_end_point ()
312 return beam_ && valid_start_point ();
315 ADD_ACKNOWLEDGER (Grace_beam_engraver, stem);
316 ADD_ACKNOWLEDGER (Grace_beam_engraver, rest);
317 ADD_TRANSLATOR (Grace_beam_engraver,
318 /* doc */ "Handles Beam events by engraving Beams. If omitted, then notes will "
319 "be printed with flags instead of beams. Only engraves beams when we "
320 " are at grace points in time. ",
322 /* accept */ "beam-event",
323 /* read */ "beamMelismaBusy beatLength allowBeamBreak subdivideBeams",