2 Sequential_iterator.cc -- implement Sequential_iterator
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
9 #include "translator-group.hh"
11 #include "sequential-iterator.hh"
12 #include "music-list.hh"
13 #include "grace-fixup.hh"
17 TODO: handling of grace notes is exquisite pain. This handling
18 should be formally specified and then the implementation verified.
23 Invariant for the data structure.
26 if (gh_pair_p (cursor_))
27 iter_->music_ == unsmob_music (ly_car (cursor_))
31 The length of musiclist from start to up to cursor_ (cursor_ not
34 here_mom_ = sum (length (musiclist [start ... cursor>)) %)
37 Sequential_iterator::Sequential_iterator ()
39 here_mom_ = Moment (0);
46 Sequential_iterator::get_music_list () const
52 Sequential_iterator::do_quit ()
62 Sequential_iterator::derived_mark () const
65 scm_gc_mark (iter_->self_scm ());
66 scm_gc_mark (cursor_);
71 Sequential_iterator::derived_substitute (Context *f, Context *t)
74 iter_->substitute_outlet (f, t);
78 TODO: this should be made lazily.
81 create_grace_fixup_list (SCM cursor)
85 Grace_fixup *head = 0;
86 Grace_fixup **tail = &head;
88 for (; gh_pair_p (cursor); cursor = ly_cdr (cursor))
90 Music *mus = unsmob_music (ly_car (cursor));
91 Moment s = mus->start_mom ();
92 Moment l = mus->get_length () - s;
96 if (last != Moment (-1))
98 Grace_fixup *p = new Grace_fixup;
100 p->length_ = here - last;
101 p->grace_start_ = s.grace_part_;
104 tail = &(*tail)->next_;
107 here.grace_part_ = s.grace_part_;
121 Sequential_iterator::construct_children ()
123 cursor_ = get_music_list ();
126 if (gh_pair_p (cursor_))
128 Music *m = unsmob_music (ly_car (cursor_));
129 iter_ = unsmob_iterator (get_iterator (m));
132 while (iter_ && !iter_->ok ())
137 last_mom_ = Moment (-1);
138 here_mom_ = get_music ()->start_mom ();
139 grace_fixups_ = create_grace_fixup_list (cursor_);
142 iter_->ok () is tautology, but what the heck.
144 if (iter_ && iter_->ok ())
150 maintain invariants: change cursor, iter and here_mom_ in one fell
154 Sequential_iterator::next_element (bool)
156 Moment len =iter_->music_get_length () - iter_->music_start_mom ();
157 assert (!grace_fixups_ || grace_fixups_->start_ >= here_mom_);
160 && get_grace_fixup ())
162 Grace_fixup *gf = get_grace_fixup ();
164 last_mom_ = here_mom_;
165 here_mom_ += gf->length_;
166 here_mom_.grace_part_ += gf->grace_start_;
170 else if (len.grace_part_ && !len.main_part_)
172 last_mom_ = here_mom_;
173 here_mom_.grace_part_ =0;
178 !len.grace_part_ || len.main_part_
180 We skip over a big chunk (mainpart != 0). Any starting graces
181 in that chunk should be in len.grace_part_
184 last_mom_ = here_mom_;;
188 cursor_ = ly_cdr (cursor_);
191 if (gh_pair_p (cursor_))
192 iter_ = unsmob_iterator (get_iterator (unsmob_music (ly_car (cursor_))));
198 move to context of child iterator if it is deeper down in the
202 Sequential_iterator::descend_to_child ()
204 Context * child_report = child_report = iter_->get_outlet ();
205 Context * me_report = get_outlet ();
207 Context * c = child_report;
208 while (c && c != me_report)
210 c = c->daddy_context_;
214 set_translator (child_report);
218 Sequential_iterator::process (Moment until)
222 Grace_fixup * gf = get_grace_fixup ();
224 && gf->start_ + gf->length_
225 + Moment (Rational (0), gf->grace_start_) == until)
228 do the stuff/note/rest preceding a grace.
230 iter_->process (iter_->music_get_length ());
234 Moment w = until - here_mom_ + iter_->music_start_mom ();
239 if the iter is still OK, there must be events left that have
253 Sequential_iterator::pending_moment () const
255 Moment cp = iter_->pending_moment ();
258 Fix-up a grace note halfway in the music.
260 Grace_fixup * gf = get_grace_fixup ();
262 && gf->length_ + iter_->music_start_mom () == cp)
264 return here_mom_ + gf->length_ + Moment (0, gf->grace_start_);
268 Fix-up a grace note at the start of the music.
270 return cp + here_mom_ - iter_->music_start_mom ();
275 Sequential_iterator::ok () const
281 Sequential_iterator::try_music_in_children (Music *m) const
283 return iter_ ? iter_->try_music (m) : 0;
286 IMPLEMENT_CTOR_CALLBACK (Sequential_iterator);
289 Sequential_iterator::run_always () const
291 return iter_ ? iter_->run_always () : false;
295 Sequential_iterator::next_grace_fixup ()
297 Grace_fixup * n = grace_fixups_->next_;
298 delete grace_fixups_;
303 Sequential_iterator::get_grace_fixup () const
305 if (grace_fixups_ && grace_fixups_->start_ == here_mom_)
306 return grace_fixups_;