2 tempo-performer.cc -- implement Tempo_performer
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--2006 Jan Nieuwenhuizen <janneke@gnu.org>
9 #include "performer.hh"
11 #include "audio-item.hh"
12 #include "duration.hh"
13 #include "stream-event.hh"
15 #include "translator.icc"
17 class Tempo_performer : public Performer
20 TRANSLATOR_DECLARATIONS (Tempo_performer);
25 void stop_translation_timestep ();
26 void process_music ();
27 DECLARE_TRANSLATOR_LISTENER (metronome_change);
29 Stream_event *tempo_event_;
33 Tempo_performer::Tempo_performer ()
39 Tempo_performer::~Tempo_performer ()
44 Tempo_performer::process_music ()
48 SCM met = tempo_event_->get_property ("metronome-count");
49 Duration *d = unsmob_duration (tempo_event_->get_property ("tempo-unit"));
51 Rational r = (d->get_length () / Moment (Rational (1, 4)) * Moment (scm_to_int (met))).main_part_;
53 audio_ = new Audio_tempo (r.to_int ());
55 Audio_element_info info (audio_, tempo_event_);
56 announce_element (info);
62 Tempo_performer::stop_translation_timestep ()
66 play_element (audio_);
71 IMPLEMENT_TRANSLATOR_LISTENER (Tempo_performer, metronome_change);
73 Tempo_performer::listen_metronome_change (Stream_event *event)
78 ADD_TRANSLATOR (Tempo_performer, "", "",
79 "metronome-change-event",