mirror of
https://github.com/bevyengine/bevy
synced 2024-12-21 10:33:08 +00:00
ed151e756c
# Objective What's that? Another PR for the grand migration to required components? This time, audio! ## Solution Deprecate `AudioSourceBundle`, `AudioBundle`, and `PitchBundle`, as per the [chosen proposal](https://hackmd.io/@bevy/required_components/%2Fzxgp-zMMRUCdT7LY1ZDQwQ). However, we cannot call the component `AudioSource`, because that's what the stored asset is called. I deliberated on a few names, like `AudioHandle`, or even just `Audio`, but landed on `AudioPlayer`, since it's probably the most accurate and "nice" name for this. Open to alternatives though. --- ## Migration Guide Replace all insertions of `AudioSoucreBundle`, `AudioBundle`, and `PitchBundle` with the `AudioPlayer` component. The other components required by it will now be inserted automatically. In cases where the generics cannot be inferred, you may need to specify them explicitly. For example: ```rust commands.spawn(AudioPlayer::<AudioSource>(asset_server.load("sounds/sick_beats.ogg"))); ```
103 lines
2.8 KiB
Rust
103 lines
2.8 KiB
Rust
//! Shows how to create a custom [`Decodable`] type by implementing a Sine wave.
|
|
|
|
use bevy::{
|
|
audio::{AddAudioSource, AudioPlugin, Source},
|
|
math::ops,
|
|
prelude::*,
|
|
reflect::TypePath,
|
|
utils::Duration,
|
|
};
|
|
|
|
// This struct usually contains the data for the audio being played.
|
|
// This is where data read from an audio file would be stored, for example.
|
|
// This allows the type to be registered as an asset.
|
|
#[derive(Asset, TypePath)]
|
|
struct SineAudio {
|
|
frequency: f32,
|
|
}
|
|
// This decoder is responsible for playing the audio,
|
|
// and so stores data about the audio being played.
|
|
struct SineDecoder {
|
|
// how far along one period the wave is (between 0 and 1)
|
|
current_progress: f32,
|
|
// how much we move along the period every frame
|
|
progress_per_frame: f32,
|
|
// how long a period is
|
|
period: f32,
|
|
sample_rate: u32,
|
|
}
|
|
|
|
impl SineDecoder {
|
|
fn new(frequency: f32) -> Self {
|
|
// standard sample rate for most recordings
|
|
let sample_rate = 44_100;
|
|
SineDecoder {
|
|
current_progress: 0.,
|
|
progress_per_frame: frequency / sample_rate as f32,
|
|
period: std::f32::consts::PI * 2.,
|
|
sample_rate,
|
|
}
|
|
}
|
|
}
|
|
|
|
// The decoder must implement iterator so that it can implement `Decodable`.
|
|
impl Iterator for SineDecoder {
|
|
type Item = f32;
|
|
|
|
fn next(&mut self) -> Option<Self::Item> {
|
|
self.current_progress += self.progress_per_frame;
|
|
// we loop back round to 0 to avoid floating point inaccuracies
|
|
self.current_progress %= 1.;
|
|
Some(ops::sin(self.period * self.current_progress))
|
|
}
|
|
}
|
|
// `Source` is what allows the audio source to be played by bevy.
|
|
// This trait provides information on the audio.
|
|
impl Source for SineDecoder {
|
|
fn current_frame_len(&self) -> Option<usize> {
|
|
None
|
|
}
|
|
|
|
fn channels(&self) -> u16 {
|
|
1
|
|
}
|
|
|
|
fn sample_rate(&self) -> u32 {
|
|
self.sample_rate
|
|
}
|
|
|
|
fn total_duration(&self) -> Option<Duration> {
|
|
None
|
|
}
|
|
}
|
|
|
|
// Finally `Decodable` can be implemented for our `SineAudio`.
|
|
impl Decodable for SineAudio {
|
|
type DecoderItem = <SineDecoder as Iterator>::Item;
|
|
|
|
type Decoder = SineDecoder;
|
|
|
|
fn decoder(&self) -> Self::Decoder {
|
|
SineDecoder::new(self.frequency)
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
let mut app = App::new();
|
|
// register the audio source so that it can be used
|
|
app.add_plugins(DefaultPlugins.set(AudioPlugin {
|
|
global_volume: GlobalVolume::new(0.2),
|
|
..default()
|
|
}))
|
|
.add_audio_source::<SineAudio>()
|
|
.add_systems(Startup, setup)
|
|
.run();
|
|
}
|
|
|
|
fn setup(mut assets: ResMut<Assets<SineAudio>>, mut commands: Commands) {
|
|
// add a `SineAudio` to the asset server so that it can be played
|
|
let audio_handle = assets.add(SineAudio {
|
|
frequency: 440., // this is the frequency of A4
|
|
});
|
|
commands.spawn(AudioPlayer(audio_handle));
|
|
}
|