2 beam-engraver.cc -- implement Beam_engraver
4 source file of the GNU LilyPond music typesetter
6 (c) 1998--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
10 #include "engraver.hh"
16 #include "score-engraver.hh"
18 #include "drul-array.hh"
23 class Beam_engraver : public Engraver
28 Spanner *finished_beam_;
30 Music * prev_start_ev_;
34 Beaming_info_list * beam_info_;
35 Beaming_info_list * finished_beam_info_;
37 /// location within measure where beam started.
38 Moment beam_start_location_;
40 /// moment (global time) where beam started.
41 Moment beam_start_mom_;
43 bool subdivide_beams_;
47 void set_melisma (bool);
49 Moment last_stem_added_at_;
50 virtual void stop_translation_timestep ();
51 virtual void start_translation_timestep ();
52 virtual void finalize ();
54 virtual void acknowledge_grob (Grob_info);
55 virtual bool try_music (Music*);
56 virtual void process_music ();
58 virtual bool valid_start_point();
59 virtual bool valid_end_point ();
62 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 daddy_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");
146 SCM smp = get_property ("measurePosition");
147 Moment mp = (unsmob_moment (smp)) ? *unsmob_moment (smp) : Moment (0);
149 beam_start_location_ = mp;
150 beam_start_mom_ = now_mom ();
152 beam_info_ = new Beaming_info_list;
154 /* urg, must copy to Auto_beam_engraver too */
155 announce_grob (beam_, start_ev_->self_scm());
162 Beam_engraver::typeset_beam ()
166 finished_beam_info_->beamify(beat_length_, subdivide_beams_);
167 Beam::set_beaming (finished_beam_, finished_beam_info_);
168 typeset_grob (finished_beam_);
169 delete finished_beam_info_;
170 finished_beam_info_ =0;
176 Beam_engraver::start_translation_timestep ()
184 subdivide_beams_ = to_boolean(get_property("subdivideBeams"));
185 beat_length_ = *unsmob_moment (get_property ("beatLength"));
190 Beam_engraver::stop_translation_timestep ()
195 finished_beam_ = beam_;
196 finished_beam_info_ = beam_info_;
207 Beam_engraver::finalize ()
212 prev_start_ev_->origin ()->warning (_ ("unterminated beam"));
215 we don't typeset it, (we used to, but it was commented
216 out. Reason unknown) */
223 Beam_engraver::acknowledge_grob (Grob_info info)
227 if (Rest::has_interface (info.grob_))
229 info.grob_->add_offset_callback (Beam::rest_collision_callback_proc, Y_AXIS);
231 else if (Stem::has_interface (info.grob_))
233 Moment now = now_mom();
235 if (!valid_start_point ())
238 Item *stem = dynamic_cast<Item*> (info.grob_);
239 if (Stem::get_beam (stem))
242 Music* m = info.music_cause();
243 if (!m->is_mus_type ("rhythmic-event"))
245 String s = _ ("stem must have Rhythmic structure");
246 if (info.music_cause ())
247 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_int2num (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);
282 ENTER_DESCRIPTION(Beam_engraver,
283 /* descr */ "Handles Beam events by engraving Beams. If omitted, then notes will be "
284 "printed with flags instead of beams.",
286 /* accepts */ "beam-event",
287 /* acks */ "stem-interface rest-interface",
288 /* reads */ "beamMelismaBusy beatLength subdivideBeams",
292 class Grace_beam_engraver : public Beam_engraver
295 TRANSLATOR_DECLARATIONS(Grace_beam_engraver);
298 virtual bool valid_start_point();
299 virtual bool valid_end_point ();
302 Grace_beam_engraver::Grace_beam_engraver()
307 Grace_beam_engraver::valid_start_point()
309 Moment n = now_mom ();
311 return n.grace_part_ != Rational (0);
316 Grace_beam_engraver::valid_end_point ()
318 return beam_ && valid_start_point ();
323 ENTER_DESCRIPTION(Grace_beam_engraver,
324 /* descr */ "Handles Beam events by engraving Beams. If omitted, then notes will "
325 "be printed with flags instead of beams. Only engraves beams when we "
326 " are at grace points in time. "
329 /* accepts */ "beam-event",
330 /* acks */ "stem-interface rest-interface",
331 /* reads */ "beamMelismaBusy beatLength allowBeamBreak subdivideBeams",