amethyst_audio 0.15.3

Audio support for Amethyst
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141

use std::{
    iter::Iterator,
    mem::replace,
    sync::{
        atomic::{AtomicBool, Ordering},
        Arc,
    },
};

use derive_new::new;
use rodio::SpatialSink;

#[cfg(feature = "profiler")]
use thread_profiler::profile_scope;

use amethyst_core::{
    ecs::prelude::{
        Entities, Entity, Join, Read, ReadStorage, System, SystemData, World, WriteStorage,
    },
    math::convert,
    transform::Transform,
    SystemDesc,
};

use crate::{
    components::{AudioEmitter, AudioListener},
    end_signal::EndSignalSource,
    output::Output,
};

/// Builds an `AudioSystem`.
#[derive(Default, Debug, new)]
pub struct AudioSystemDesc {
    /// Audio `Output`.
    pub output: Output,
}

impl<'a, 'b> SystemDesc<'a, 'b, AudioSystem> for AudioSystemDesc {
    fn build(self, world: &mut World) -> AudioSystem {
        <AudioSystem as System<'_>>::SystemData::setup(world);

        world.insert(self.output.clone());

        AudioSystem::new(self.output)
    }
}

/// Syncs 3D transform data with the audio engine to provide 3D audio.
#[derive(Debug, Default, new)]
pub struct AudioSystem(Output);

/// Add this structure to world as a resource with ID 0 to select an entity whose AudioListener
/// component will be used.  If this resource isn't found then the system will arbitrarily select
/// the first AudioListener it finds.
#[derive(Debug)]
pub struct SelectedListener(pub Entity);

impl<'a> System<'a> for AudioSystem {
    type SystemData = (
        Option<Read<'a, Output>>,
        Option<Read<'a, SelectedListener>>,
        Entities<'a>,
        ReadStorage<'a, Transform>,
        ReadStorage<'a, AudioListener>,
        WriteStorage<'a, AudioEmitter>,
    );

    fn run(
        &mut self,
        (output, select_listener, entities, transform, listener, mut audio_emitter): Self::SystemData,
    ) {
        #[cfg(feature = "profiler")]
        profile_scope!("audio_system");
        // Process emitters and listener.
        if let Some((listener, entity)) = select_listener
            .as_ref()
            .and_then(|sl| listener.get(sl.0).map(|l| (l, sl.0)))
            .or_else(|| (&listener, &*entities).join().next())
        {
            if let Some(listener_transform) = select_listener
                .as_ref()
                .and_then(|sl| transform.get(sl.0))
                .or_else(|| transform.get(entity))
            {
                let listener_transform = listener_transform.global_matrix();
                let left_ear_position: [f32; 3] = {
                    let pos = listener_transform
                        .transform_point(&listener.left_ear)
                        .to_homogeneous()
                        .xyz();
                    [convert(pos.x), convert(pos.y), convert(pos.z)]
                };
                let right_ear_position: [f32; 3] = {
                    let pos = listener_transform
                        .transform_point(&listener.right_ear)
                        .to_homogeneous()
                        .xyz();
                    [convert(pos.x), convert(pos.y), convert(pos.z)]
                };
                for (transform, mut audio_emitter) in (&transform, &mut audio_emitter).join() {
                    let emitter_position: [f32; 3] = {
                        let x = transform.global_matrix()[(0, 3)];
                        let y = transform.global_matrix()[(1, 3)];
                        let z = transform.global_matrix()[(2, 3)];
                        [convert(x), convert(y), convert(z)]
                    };
                    // Remove all sinks whose sounds have ended.
                    audio_emitter.sinks.retain(|s| !s.1.load(Ordering::Relaxed));
                    for &mut (ref mut sink, _) in &mut audio_emitter.sinks {
                        sink.set_emitter_position(emitter_position);
                        sink.set_left_ear_position(left_ear_position);
                        sink.set_right_ear_position(right_ear_position);
                    }
                    if audio_emitter.sinks.is_empty() {
                        if let Some(mut picker) = replace(&mut audio_emitter.picker, None) {
                            if picker(&mut audio_emitter) {
                                audio_emitter.picker = Some(picker);
                            }
                        }
                    }
                    while let Some(source) = audio_emitter.sound_queue.pop() {
                        if let Some(output) = &output {
                            let sink = SpatialSink::new(
                                &output.device,
                                emitter_position,
                                left_ear_position,
                                right_ear_position,
                            );
                            let atomic_bool = Arc::new(AtomicBool::new(false));
                            let clone = atomic_bool.clone();
                            sink.append(EndSignalSource::new(source, move || {
                                clone.store(true, Ordering::Relaxed);
                            }));
                            audio_emitter.sinks.push((sink, atomic_bool));
                        }
                    }
                }
            }
        }
    }
}