2 stem-grav.cc -- implement Stem_engraver
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
9 #include "staff-symbol-referencer.hh"
10 #include "rhythmic-head.hh"
14 #include "stem-tremolo.hh"
16 #include "translator-group.hh"
17 #include "engraver.hh"
22 Make stems upon receiving noteheads.
24 class Stem_engraver : public Engraver
26 TRANSLATOR_DECLARATIONS(Stem_engraver);
28 virtual void acknowledge_grob (Grob_info);
29 virtual void stop_translation_timestep ();
30 virtual bool try_music (Music*);
39 Stem_engraver::Stem_engraver ()
49 Stem_engraver::acknowledge_grob (Grob_info i)
52 if (Rhythmic_head::has_interface (h))
54 if (Rhythmic_head::get_stem (h))
57 /* Reverted to the old method so chord tremolos work again. /MB
61 Music * m = i.music_cause ();
62 if (m->is_mus_type ("rhythmic-event"))
63 duration_log = unsmob_duration (m->get_mus_property ("duration"))-> duration_log ();
67 stem_ = make_item ("Stem");
69 stem_->set_grob_property ("duration-log", gh_int2scm (duration_log));
74 Stem tremolo is never applied to a note by default,
75 is must me evuested. But there is a default for the
80 the first and last (quarter) note bothe get one tremolo flag.
82 int requested_type = gh_scm2int (tremolo_ev_->get_mus_property ("tremolo-type"));
83 SCM f = get_property ("tremoloFlags");
86 requested_type = gh_scm2int (f);
90 daddy_trans_->set_property ("tremoloFlags", gh_int2scm (requested_type));
92 int tremolo_flags = intlog2 (requested_type) - 2
93 - (duration_log > 2 ? duration_log - 2 : 0);
94 if (tremolo_flags <= 0)
96 tremolo_ev_->origin()->warning (_("tremolo duration is too long"));
102 tremolo_ = make_item ("StemTremolo");
103 announce_grob(tremolo_, tremolo_ev_->self_scm());
106 The number of tremolo flags is the number of flags of
107 the tremolo-type minus the number of flags of the note
110 tremolo_->set_grob_property ("flag-count",
111 gh_int2scm (tremolo_flags));
112 tremolo_->set_parent (stem_, X_AXIS);
113 stem_->set_grob_property ("tremolo-flag", tremolo_->self_scm ());
118 We announce the cause of the head as cause of the stem.
119 The stem needs a rhythmic structure to fit it into a beam. */
120 announce_grob(stem_, i.music_cause ()->self_scm());
123 if (Stem::duration_log (stem_) != duration_log)
125 i.music_cause ()->origin ()->warning (_f ("Adding note head to incompatible stem (type = %d)", 1 << Stem::duration_log (stem_))
126 + _f ("Don't you want polyphonic voices instead?")
130 Stem::add_head (stem_,h);
135 Stem_engraver::stop_translation_timestep ()
139 Stem_tremolo::set_stem (tremolo_, stem_);
140 typeset_grob (tremolo_);
146 SCM prop = get_property ("stemLeftBeamCount");
147 if (gh_number_p (prop))
149 Stem::set_beaming (stem_,gh_scm2int (prop),LEFT);
150 daddy_trans_->unset_property (ly_symbol2scm ("stemLeftBeamCount"));
152 prop = get_property ("stemRightBeamCount");
153 if (gh_number_p (prop))
155 Stem::set_beaming (stem_,gh_scm2int (prop), RIGHT);
156 daddy_trans_->unset_property (ly_symbol2scm ("stemRightBeamCount"));
159 typeset_grob (stem_);
168 Stem_engraver::try_music (Music* r)
170 if (r->is_mus_type ("tremolo-event"))
178 ENTER_DESCRIPTION(Stem_engraver,
179 /* descr */ "Create stems and single-stem tremolos. It also works together with "
180 "the beam engraver for overriding beaming.",
181 /* creats*/ "Stem StemTremolo",
182 /* accepts */ "tremolo-event",
183 /* acks */ "rhythmic-head-interface",
184 /* reads */ "tremoloFlags stemLeftBeamCount stemRightBeamCount",