2 files changed, 38 insertions, 3 deletions

diff --git a/mumd/src/audio/input.rs b/mumd/src/audio/input.rs
index 25d15d5..37ea60a 100644
--- a/mumd/src/audio/input.rs
+++ b/mumd/src/audio/input.rs
@@ -1,3 +1,4 @@
+//! Listens to the microphone and sends it to the networking.
 use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
 use cpal::{InputCallbackInfo, Sample, SampleFormat, SampleRate, StreamConfig};
 use log::*;
@@ -8,6 +9,7 @@ use crate::audio::transformers::{NoiseGate, Transformer};
 use crate::error::{AudioError, AudioStream};
 use crate::state::StatePhase;
 
+/// Generates a callback that receives [Sample]s and sends them as floats to a [futures_channel::mpsc::Sender].
 pub fn callback<T: Sample>(
     mut input_sender: futures_channel::mpsc::Sender<Vec<u8>>,
     mut transformers: Vec<Box<dyn Transformer + Send + 'static>>,
@@ -43,11 +45,19 @@ pub fn callback<T: Sample>(
     }
 }
 
+/// Something that can listen to audio and send it somewhere.
+/// 
+/// One sample is assumed to be an encoded opus frame. See [opus::Encoder].
 pub trait AudioInputDevice {
+    /// Starts the device.
     fn play(&self) -> Result<(), AudioError>;
+    /// Stops the device.
     fn pause(&self) -> Result<(), AudioError>;
+    /// Sets the input volume of the device.
     fn set_volume(&self, volume: f32);
+    /// Returns a receiver to this device's values.
     fn sample_receiver(&mut self) -> Option<futures_channel::mpsc::Receiver<Vec<u8>>>;
+    /// The amount of channels this device has.
     fn num_channels(&self) -> usize;
 }
 
@@ -59,6 +69,7 @@ pub struct DefaultAudioInputDevice {
 }
 
 impl DefaultAudioInputDevice {
+    /// Initializes the default audio input.
     pub fn new(
         input_volume: f32,
         phase_watcher: watch::Receiver<StatePhase>,
@@ -162,17 +173,21 @@ impl AudioInputDevice for DefaultAudioInputDevice {
             .play()
             .map_err(|e| AudioError::InputPlayError(e))
     }
+
     fn pause(&self) -> Result<(), AudioError> {
         self.stream
             .pause()
             .map_err(|e| AudioError::InputPauseError(e))
     }
+
     fn set_volume(&self, volume: f32) {
         self.volume_sender.send(volume).unwrap();
     }
+
     fn sample_receiver(&mut self) -> Option<futures_channel::mpsc::Receiver<Vec<u8>>> {
         self.sample_receiver.take()
     }
+
     fn num_channels(&self) -> usize {
         self.channels as usize
     }
diff --git a/mumd/src/audio/output.rs b/mumd/src/audio/output.rs
index cdb7b8e..b945710 100644
--- a/mumd/src/audio/output.rs
+++ b/mumd/src/audio/output.rs
@@ -1,3 +1,5 @@
+//! Receives audio packets from the networking and plays them.
+
 use crate::audio::SAMPLE_RATE;
 use crate::error::{AudioError, AudioStream};
 use crate::network::VoiceStreamType;
@@ -16,12 +18,13 @@ use tokio::sync::watch;
 
 type ClientStreamKey = (VoiceStreamType, u32);
 
+/// State for decoding audio received from another user.
 pub struct ClientAudioData {
     buf: Bounded<Vec<f32>>,
     output_channels: opus::Channels,
-    //we need two since a client can hypothetically send both mono
-    //and stereo packets, and we can't switch a decoder on the fly
-    //to reuse it
+    // We need both since a client can hypothetically send both mono
+    // and stereo packets, and we can't switch a decoder on the fly
+    // to reuse it.
     mono_decoder: opus::Decoder,
     stereo_decoder: opus::Decoder,
 }
@@ -62,6 +65,7 @@ impl ClientAudioData {
     }
 }
 
+/// Collected state for client opus decoders and sound effects.
 pub struct ClientStream {
     buffer_clients: HashMap<ClientStreamKey, ClientAudioData>,
     buffer_effects: VecDeque<f32>,
@@ -90,6 +94,7 @@ impl ClientStream {
         )
     }
 
+    /// Decodes a voice packet.
     pub fn decode_packet(&mut self, client: ClientStreamKey, payload: VoicePacketPayload) {
         match payload {
             VoicePacketPayload::Opus(bytes, _eot) => {
@@ -101,12 +106,19 @@ impl ClientStream {
         }
     }
 
+    /// Extends the sound effect buffer queue with some received values.
     pub fn add_sound_effect(&mut self, values: &[f32]) {
         self.buffer_effects.extend(values.iter().copied());
     }
 }
 
+/// Adds two values in some saturating way.
+/// 
+/// Since we support [f32], [i16] and [u16] we need some way of adding two values
+/// without peaking above/below the edge values. This trait ensures that we can
+/// use all three primitive types as a generic parameter.
 pub trait SaturatingAdd {
+    /// Adds two values in some saturating way. See trait documentation.
     fn saturating_add(self, rhs: Self) -> Self;
 }
 
@@ -140,14 +152,20 @@ pub trait AudioOutputDevice {
     fn client_streams(&self) -> Arc<Mutex<ClientStream>>;
 }
 
+/// The default audio output device, as determined by [cpal].
 pub struct DefaultAudioOutputDevice {
     config: StreamConfig,
     stream: cpal::Stream,
+    /// The client stream per user ID. A separate stream is kept for UDP and TCP.
+    ///
+    /// Shared with [super::AudioOutput].
     client_streams: Arc<Mutex<ClientStream>>,
+    /// Output volume configuration.
     volume_sender: watch::Sender<f32>,
 }
 
 impl DefaultAudioOutputDevice {
+    /// Initializes the default audio output.
     pub fn new(
         output_volume: f32,
         user_volumes: Arc<Mutex<HashMap<u32, (f32, bool)>>>,
@@ -247,6 +265,8 @@ impl AudioOutputDevice for DefaultAudioOutputDevice {
     }
 }
 
+/// Returns a function that fills a buffer with audio from client streams
+/// modified according to some audio configuration.
 pub fn callback<T: Sample + AddAssign + SaturatingAdd + std::fmt::Display>(
     user_bufs: Arc<Mutex<ClientStream>>,
     output_volume_receiver: watch::Receiver<f32>,