2 auto-beam-engraver.cc -- implement Auto_beam_engraver
4 source file of the GNU LilyPond music typesetter
6 (c) 1999--2004 Jan Nieuwenhuizen <janneke@gnu.org>
15 #include "engraver-group-engraver.hh"
16 #include "bar-line.hh"
18 #include "engraver.hh"
21 #include "duration.hh"
24 class Auto_beam_engraver : public Engraver
26 TRANSLATOR_DECLARATIONS (Auto_beam_engraver);
28 virtual void stop_translation_timestep ();
29 virtual void start_translation_timestep ();
30 virtual void process_music ();
31 virtual bool try_music (Music*);
32 virtual void finalize ();
33 virtual void acknowledge_grob (Grob_info);
34 virtual void process_acknowledged_grobs ();
37 bool test_moment (Direction, Moment);
38 void consider_begin (Moment);
39 void consider_end (Moment);
40 Spanner* create_beam ();
44 bool is_same_grace_state (Grob* e);
49 shortest_mom is the shortest note in the beam.
52 Spanner *finished_beam_;
53 Link_array<Item>* stems_;
59 Projected ending of the beam we're working on.
62 Moment beam_start_moment_;
63 Moment beam_start_location_;
65 bool subdivide_beams_;
68 // We act as if beam were created, and start a grouping anyway.
69 Beaming_info_list*grouping_;
70 SCM beam_settings_ ; // ugh. should protect ?
72 Beaming_info_list*finished_grouping_;
76 Auto_beam_engraver::process_music ()
78 if (scm_is_string (get_property ("whichBar")))
80 consider_end (shortest_mom_);
85 || !to_boolean (get_property ("autoBeaming")))
87 consider_end (shortest_mom_);
93 Auto_beam_engraver::Auto_beam_engraver ()
98 shortest_mom_ = Moment (Rational (1, 8));
100 finished_grouping_ = 0;
102 beam_settings_ = SCM_EOL;
107 Auto_beam_engraver::try_music (Music*m)
109 if (m->is_mus_type ("beam-forbid-event"))
119 Determine end moment for auto beaming (or begin moment, but mostly
120 0==anywhere) In order of increasing priority:
122 i. begin anywhere, end at every beat
123 ii. end * <num> <den>
124 iii. end <type> <num> <den>
132 [to be defined in config file]
133 i. easy catch-all rule
134 ii. exceptions for time signature
135 iii. exceptions for time signature, for specific duration type
139 v. override for specific duration type
143 Auto_beam_engraver::test_moment (Direction dir, Moment test_mom)
145 Moment now = now_mom ();
152 SCM wild = scm_list_n (ly_symbol2scm ("*"), ly_symbol2scm ("*"), SCM_UNDEFINED);
155 function = scm_list_n (ly_symbol2scm ("begin"), SCM_UNDEFINED);
157 function = scm_list_n (ly_symbol2scm ("end"), SCM_UNDEFINED);
159 Moment one_beat = *unsmob_moment (get_property ("beatLength"));
160 int num = int ((*unsmob_moment (get_property ("measureLength")) / one_beat).main_part_);
161 int den = one_beat.den ();
162 SCM time = scm_list_n (scm_int2num (num), scm_int2num (den), SCM_UNDEFINED);
164 SCM type = scm_list_n (scm_int2num (test_mom.num ()),
165 scm_int2num (test_mom.den ()), SCM_UNDEFINED);
169 settings aren't grob-properties.
171 SCM settings = get_property ("autoBeamSettings");
175 /* begin beam at any position
176 (and fallback for end) */
179 /* end beam at end of beat */
182 SCM beat (get_property ("beatLength"));
184 if (unsmob_moment (beat))
185 moment = *unsmob_moment (beat);
188 /* second guess: property generic time exception */
189 SCM m = scm_assoc (ly_append3 (function, wild, time), settings);
191 if (m != SCM_BOOL_F && unsmob_moment (ly_cdr (m)))
192 moment = * unsmob_moment (ly_cdr (m));
194 /* third guess: property time exception, specific for duration type */
195 m = scm_assoc (ly_append3 (function, type, time), settings);
196 if (m != SCM_BOOL_F && unsmob_moment (ly_cdr (m)))
197 moment = * unsmob_moment (ly_cdr (m));
199 /* fourth guess [user override]: property plain generic */
200 m = scm_assoc (ly_append3 (function, wild, wild), settings);
201 if (m != SCM_BOOL_F && unsmob_moment (ly_cdr (m)))
202 moment = * unsmob_moment (ly_cdr (m));
204 /* fifth guess [user override]: property plain, specific for duration type */
205 m = scm_assoc (ly_append3 (function, type, wild), settings);
206 if (m != SCM_BOOL_F && unsmob_moment (ly_cdr (m)))
207 moment = * unsmob_moment (ly_cdr (m));
210 if (moment.to_bool ())
212 /* Ugh? measurePosition can be negative, when \partial
213 We may have to fix this elsewhere (timing translator)
214 r = unsmob_moment (get_property ("measurePosition"))->mod_rat (moment);
216 Moment pos = * unsmob_moment (get_property ("measurePosition"));
217 if (pos < Moment (0))
219 Moment length = * unsmob_moment (get_property ("measureLength"));
222 r = pos.main_part_.mod_rat (moment.main_part_);
227 /* if undefined, starting is ok */
230 /* but ending is not */
238 Auto_beam_engraver::consider_begin (Moment test_mom)
240 bool on = to_boolean (get_property ("autoBeaming"));
244 bool b = test_moment (START, test_mom);
251 Auto_beam_engraver::consider_end (Moment test_mom)
255 /* Allow already started autobeam to end:
256 don't check for autoBeaming */
257 bool b = test_moment (STOP, test_mom);
264 Auto_beam_engraver::create_beam ()
266 if (to_boolean (get_property ("skipTypesetting")))
271 Spanner* beam = new Spanner (beam_settings_);
272 for (int i = 0; i < stems_->size (); i++)
275 watch out for stem tremolos and abbreviation beams
277 if (Stem::get_beam ((*stems_)[i]))
279 scm_gc_unprotect_object (beam->self_scm ());
282 Beam::add_stem (beam, (*stems_)[i]);
285 announce_grob (beam, (*stems_)[0]->self_scm ());
291 Auto_beam_engraver::begin_beam ()
293 if (stems_ || grouping_ )
295 programming_error ("already have autobeam");
299 stems_ = new Link_array<Item>;
300 grouping_ = new Beaming_info_list;
301 beam_settings_ = updated_grob_properties (context (), ly_symbol2scm ("Beam"));
303 beam_start_moment_ = now_mom ();
304 beam_start_location_ = *unsmob_moment (get_property ("measurePosition"));
305 subdivide_beams_ = ly_scm2bool (get_property ("subdivideBeams"));
306 beat_length_ = *unsmob_moment (get_property ("beatLength"));
310 Auto_beam_engraver::junk_beam ()
319 beam_settings_ = SCM_EOL;
321 shortest_mom_ = Moment (Rational (1, 8));
325 Auto_beam_engraver::end_beam ()
327 if (stems_->size () < 2)
333 finished_beam_ = create_beam ();
335 finished_grouping_ = grouping_;
339 beam_settings_ = SCM_EOL;
342 shortest_mom_ = Moment (Rational (1, 8));
346 Auto_beam_engraver::typeset_beam ()
350 finished_grouping_->beamify (beat_length_, subdivide_beams_);
351 Beam::set_beaming (finished_beam_, finished_grouping_);
354 delete finished_grouping_;
355 finished_grouping_= 0;
360 Auto_beam_engraver::start_translation_timestep ()
364 don't beam over skips
368 Moment now = now_mom ();
369 if (extend_mom_ < now)
378 Auto_beam_engraver::stop_translation_timestep ()
384 Auto_beam_engraver::finalize ()
386 /* finished beams may be typeset */
388 /* but unfinished may need another announce/acknowledge pass */
395 Auto_beam_engraver::acknowledge_grob (Grob_info info)
399 if (Beam::has_interface (info.grob_))
403 else if (Bar_line::has_interface (info.grob_))
407 else if (Rest::has_interface (info.grob_))
413 if (Stem::has_interface (info.grob_))
415 Item* stem = dynamic_cast<Item *> (info.grob_);
416 Music* m = info.music_cause ();
417 if (!m->is_mus_type ("rhythmic-event"))
419 programming_error ("Stem must have rhythmic structure");
424 Don't (start) auto-beam over empty stems; skips or rests
426 if (!Stem::head_count (stem))
433 if (Stem::get_beam (stem))
440 int durlog = unsmob_duration (m->get_property ("duration"))->duration_log ();
453 if (bool (beam_start_location_.grace_part_) != bool (now_mom ().grace_part_))
457 Moment dur = unsmob_duration (m->get_property ("duration"))->get_length ();
460 This comment has been here since long:
462 if shortest duration would change
463 consider ending and beginning beam first.
465 but the code didn't match: */
468 consider_begin (dur);
470 if (dur < shortest_mom_)
473 /* I very much suspect that we wanted: */
475 consider_end (shortest_mom_);
476 if (dur < shortest_mom_)
479 consider_end (shortest_mom_);
481 consider_begin (shortest_mom_);
487 Moment now = now_mom ();
489 grouping_->add_stem (now - beam_start_moment_ + beam_start_location_,
493 extend_mom_ = (extend_mom_ >? now) + m->get_length ();
498 Auto_beam_engraver::process_acknowledged_grobs ()
502 consider_end (shortest_mom_);
503 consider_begin (shortest_mom_);
509 Moment now = now_mom ();
510 if ((extend_mom_ < now)
511 || ((extend_mom_ == now) && (last_add_mom_ != now)))
515 else if (!stems_->size ())
525 ENTER_DESCRIPTION (Auto_beam_engraver,
526 /* descr */ "Generate beams based on measure characteristics and observed "
527 "Stems. Uses beatLength, measureLength and measurePosition to decide "
528 "when to start and stop a beam. Overriding beaming is done through "
529 "@ref{Stem_engraver} properties @code{stemLeftBeamCount} and "
530 "@code{stemRightBeamCount}. "
533 /* accepts */ "beam-forbid-event",
534 /* acks */ "stem-interface rest-interface beam-interface bar-line-interface",
535 /* reads */ "autoBeaming autoBeamSettings beatLength subdivideBeams",