1 /*
2 This file is part of LilyPond, the GNU music typesetter.
3
4 Copyright (C) 1997--2021 Jan Nieuwenhuizen <janneke@gnu.org>
5
6 LilyPond is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
10
11 LilyPond is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include "performer.hh"
21
22 #include "audio-item.hh"
23 #include "duration.hh"
24 #include "stream-event.hh"
25
26 #include "translator.icc"
27
28 class Tempo_performer : public Performer
29 {
30 public:
31 TRANSLATOR_DECLARATIONS (Tempo_performer);
32 ~Tempo_performer ();
33
34 protected:
35
36 void derived_mark () const override;
37 void stop_translation_timestep ();
38 void process_music ();
39 private:
40 Audio_tempo *audio_;
41 SCM last_tempo_;
42 };
43
44 void
derived_mark() const45 Tempo_performer::derived_mark () const
46 {
47 scm_gc_mark (last_tempo_);
48 }
49
Tempo_performer(Context * c)50 Tempo_performer::Tempo_performer (Context *c)
51 : Performer (c)
52 {
53 last_tempo_ = SCM_EOL;
54 audio_ = 0;
55 }
56
~Tempo_performer()57 Tempo_performer::~Tempo_performer ()
58 {
59 }
60
61 void
process_music()62 Tempo_performer::process_music ()
63 {
64 SCM w = get_property (this, "tempoWholesPerMinute");
65 if (unsmob<Moment> (w)
66 && !ly_is_equal (w, last_tempo_))
67 {
68 Rational r = unsmob<Moment> (w)->main_part_;
69 r *= Rational (4, 1);
70
71 audio_ = new Audio_tempo (static_cast<int> (r.trunc_int ()));
72
73 Audio_element_info info (audio_, 0);
74 announce_element (info);
75
76 last_tempo_ = w;
77 }
78 }
79
80 void
stop_translation_timestep()81 Tempo_performer::stop_translation_timestep ()
82 {
83 if (audio_)
84 {
85 audio_ = 0;
86 }
87 }
88
89 void
boot()90 Tempo_performer::boot ()
91 {
92
93 }
94
95 ADD_TRANSLATOR (Tempo_performer,
96 /* doc */
97 "",
98
99 /* create */
100 "",
101
102 /* read */
103 "tempoWholesPerMinute ",
104
105 /* write */
106 ""
107 );
108