2 stem-grav.cc -- implement Stem_engraver
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
9 #include "staff-symbol-referencer.hh"
10 #include "rhythmic-head.hh"
14 #include "stem-tremolo.hh"
18 #include "engraver.hh"
23 Make stems upon receiving noteheads.
25 class Stem_engraver : public Engraver
27 TRANSLATOR_DECLARATIONS (Stem_engraver);
29 virtual void acknowledge_grob (Grob_info);
30 virtual void stop_translation_timestep ();
31 virtual bool try_music (Music*);
40 Stem_engraver::Stem_engraver ()
50 Stem_engraver::acknowledge_grob (Grob_info i)
53 if (Rhythmic_head::has_interface (h))
55 if (Rhythmic_head::get_stem (h))
58 /* Reverted to the old method so chord tremolos work again. /MB
62 Music * m = i.music_cause ();
63 if (m->is_mus_type ("rhythmic-event"))
64 duration_log = unsmob_duration (m->get_property ("duration"))-> duration_log ();
69 We announce the cause of the head as cause of the stem.
70 The stem needs a rhythmic structure to fit it into a beam. */
71 stem_ = make_item ("Stem",i.music_cause ()->self_scm ());
73 stem_->set_property ("duration-log", scm_int2num (duration_log));
78 Stem tremolo is never applied to a note by default,
79 is must me evuested. But there is a default for the
84 the first and last (quarter) note bothe get one tremolo flag.
86 int requested_type = ly_scm2int (tremolo_ev_->get_property ("tremolo-type"));
87 SCM f = get_property ("tremoloFlags");
89 if (ly_c_number_p (f))
90 requested_type = ly_scm2int (f);
94 context ()->set_property ("tremoloFlags", scm_int2num (requested_type));
96 int tremolo_flags = intlog2 (requested_type) - 2
97 - (duration_log > 2 ? duration_log - 2 : 0);
98 if (tremolo_flags <= 0)
100 tremolo_ev_->origin ()->warning (_("tremolo duration is too long"));
106 tremolo_ = make_item ("StemTremolo", tremolo_ev_->self_scm ());
109 The number of tremolo flags is the number of flags of
110 the tremolo-type minus the number of flags of the note
113 tremolo_->set_property ("flag-count",
114 scm_int2num (tremolo_flags));
115 tremolo_->set_parent (stem_, X_AXIS);
116 stem_->set_property ("tremolo-flag", tremolo_->self_scm ());
117 tremolo_->set_property ("stem",
124 if (Stem::duration_log (stem_) != duration_log)
126 i.music_cause ()->origin ()->warning (_f ("Adding note head to incompatible stem (type = %d)", 1 << Stem::duration_log (stem_))
127 + _f ("Don't you want polyphonic voices instead?")
131 Stem::add_head (stem_,h);
136 Stem_engraver::stop_translation_timestep ()
143 toDO: junk these properties.
145 SCM prop = get_property ("stemLeftBeamCount");
146 if (ly_c_number_p (prop))
148 Stem::set_beaming (stem_,ly_scm2int (prop),LEFT);
149 context ()->unset_property (ly_symbol2scm ("stemLeftBeamCount"));
151 prop = get_property ("stemRightBeamCount");
152 if (ly_c_number_p (prop))
154 Stem::set_beaming (stem_,ly_scm2int (prop), RIGHT);
155 context ()->unset_property (ly_symbol2scm ("stemRightBeamCount"));
167 Stem_engraver::try_music (Music* r)
169 if (r->is_mus_type ("tremolo-event"))
177 ENTER_DESCRIPTION (Stem_engraver,
178 /* descr */ "Create stems and single-stem tremolos. It also works together with "
179 "the beam engraver for overriding beaming.",
180 /* creats*/ "Stem StemTremolo",
181 /* accepts */ "tremolo-event",
182 /* acks */ "rhythmic-head-interface",
183 /* reads */ "tremoloFlags stemLeftBeamCount stemRightBeamCount",