pitch/
pitch.rs

1//! This example illustrates how to play a single-frequency sound (aka a pitch)
2
3use bevy::prelude::*;
4use std::time::Duration;
5
6fn main() {
7    App::new()
8        .add_plugins(DefaultPlugins)
9        .add_message::<PlayPitch>()
10        .add_systems(Startup, setup)
11        .add_systems(Update, (play_pitch, keyboard_input_system))
12        .run();
13}
14
15#[derive(Message, Default)]
16struct PlayPitch;
17
18#[derive(Resource)]
19struct PitchFrequency(f32);
20
21fn setup(mut commands: Commands) {
22    commands.insert_resource(PitchFrequency(220.0));
23}
24
25fn play_pitch(
26    mut pitch_assets: ResMut<Assets<Pitch>>,
27    frequency: Res<PitchFrequency>,
28    mut play_pitch_reader: MessageReader<PlayPitch>,
29    mut commands: Commands,
30) {
31    for _ in play_pitch_reader.read() {
32        info!("playing pitch with frequency: {}", frequency.0);
33        commands.spawn((
34            AudioPlayer(pitch_assets.add(Pitch::new(frequency.0, Duration::new(1, 0)))),
35            PlaybackSettings::DESPAWN,
36        ));
37        info!("number of pitch assets: {}", pitch_assets.len());
38    }
39}
40
41fn keyboard_input_system(
42    keyboard_input: Res<ButtonInput<KeyCode>>,
43    mut frequency: ResMut<PitchFrequency>,
44    mut play_pitch_writer: MessageWriter<PlayPitch>,
45) {
46    if keyboard_input.just_pressed(KeyCode::ArrowUp) {
47        frequency.0 *= ops::powf(2.0f32, 1.0 / 12.0);
48    }
49    if keyboard_input.just_pressed(KeyCode::ArrowDown) {
50        frequency.0 /= ops::powf(2.0f32, 1.0 / 12.0);
51    }
52    if keyboard_input.just_pressed(KeyCode::Space) {
53        play_pitch_writer.write(PlayPitch);
54    }
55}
pitch/pitch.rs

pitch/
pitch.rs
