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>
10 #include "directional-element-interface.hh"
11 #include "engraver.hh"
15 #include "rhythmic-head.hh"
16 #include "script-interface.hh"
17 #include "staff-symbol-referencer.hh"
18 #include "stem-tremolo.hh"
23 Make stems upon receiving noteheads.
25 class Stem_engraver : public Engraver
31 TRANSLATOR_DECLARATIONS (Stem_engraver);
34 void add_script (Grob *);
35 void make_stem (Grob_info);
36 virtual void acknowledge_grob (Grob_info);
37 virtual void stop_translation_timestep ();
38 virtual bool try_music (Music *);
41 Stem_engraver::Stem_engraver ()
50 Stem_engraver::make_stem (Grob_info gi)
52 /* Announce the cause of the head as cause of the stem. The
53 stem needs a rhythmic structure to fit it into a beam. */
54 stem_ = make_item ("Stem", gi.music_cause ()->self_scm ());
56 int duration_log = gi.music_cause ()->duration_log ();
57 stem_->set_property ("duration-log", scm_int2num (duration_log));
61 /* Stem tremolo is never applied to a note by default,
62 is must me requested. But there is a default for the
67 the first and last (quarter) note bothe get one tremolo flag. */
69 = ly_scm2int (tremolo_ev_->get_property ("tremolo-type"));
70 SCM f = get_property ("tremoloFlags");
73 if (ly_c_number_p (f))
74 requested_type = ly_scm2int (f);
79 context ()->set_property ("tremoloFlags", scm_int2num (requested_type));
81 int tremolo_flags = intlog2 (requested_type) - 2
82 - (duration_log > 2 ? duration_log - 2 : 0);
83 if (tremolo_flags <= 0)
85 tremolo_ev_->origin ()->warning (_("tremolo duration is too long"));
91 tremolo_ = make_item ("StemTremolo", tremolo_ev_->self_scm ());
93 /* The number of tremolo flags is the number of flags of the
94 tremolo-type minus the number of flags of the note itself. */
95 tremolo_->set_property ("flag-count", scm_int2num (tremolo_flags));
96 tremolo_->set_parent (stem_, X_AXIS);
97 stem_->set_property ("tremolo-flag", tremolo_->self_scm ());
98 tremolo_->set_property ("stem", stem_->self_scm ());
104 Stem_engraver::add_script (Grob *script)
106 Direction d = get_grob_direction (script);
107 if (d == UP || d == DOWN)
109 char const *property = d == UP ? "script-up" : "script-down";
110 stem_->set_property (property,
111 scm_cons (script->self_scm (),
112 stem_->get_property (property)));
117 Stem_engraver::acknowledge_grob (Grob_info gi)
119 if (Rhythmic_head::has_interface (gi.grob_))
121 if (Rhythmic_head::get_stem (gi.grob_))
127 int duration_log = gi.music_cause ()->duration_log ();
128 if (Stem::duration_log (stem_) != duration_log)
131 gi.music_cause ()->origin ()->warning (_f ("Adding note head to incompatible stem (type = %d)", 1 << Stem::duration_log (stem_)));
133 gi.music_cause ()->origin ()->warning (_f ("Don't you want polyphonic voices instead?"));
136 Stem::add_head (stem_, gi.grob_);
138 else if (Script_interface::has_interface (gi.grob_))
139 add_script (gi.grob_);
143 Stem_engraver::stop_translation_timestep ()
148 /* FIXME: junk these properties. */
149 SCM prop = get_property ("stemLeftBeamCount");
150 if (ly_c_number_p (prop))
152 Stem::set_beaming (stem_,ly_scm2int (prop),LEFT);
153 context ()->unset_property (ly_symbol2scm ("stemLeftBeamCount"));
155 prop = get_property ("stemRightBeamCount");
156 if (ly_c_number_p (prop))
158 Stem::set_beaming (stem_,ly_scm2int (prop), RIGHT);
159 context ()->unset_property (ly_symbol2scm ("stemRightBeamCount"));
167 Stem_engraver::try_music (Music *m)
169 if (m->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",