Merge branch 'shandley/audio-channel-types' into 'master'

Use non-spatial audio sinks for music

Closes #463

See merge request veloren/veloren!794

Cargo.lock

@@ -391,11 +391,6 @@ dependencies = [
  "unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "claxon"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "clipboard-win"
 version = "2.2.0"
@@ -1583,14 +1578,6 @@ name = "lzw"
 version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "mach"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "malloc_buf"
 version = "0.0.6"
@@ -1666,23 +1653,6 @@ dependencies = [
  "x11-dl 2.18.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "minimp3"
-version = "0.3.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "minimp3-sys 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "slice-deque 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "minimp3-sys"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "cc 1.0.47 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "mio"
 version = "0.6.21"
@@ -2555,15 +2525,13 @@ dependencies = [
 
 [[package]]
 name = "rodio"
-version = "0.9.0"
+version = "0.10.0"
-source = "git+https://github.com/RustAudio/rodio?rev=e5474a2#e5474a2ef15f2d0a3bae2538de159b6d3e5bdf79"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "claxon 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "cpal 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "hound 3.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lewton 0.9.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "minimp3 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2816,16 +2784,6 @@ name = "slab"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "slice-deque"
-version = "0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
- "mach 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "smallvec"
 version = "0.6.13"
@@ -3300,7 +3258,7 @@ dependencies = [
  "msgbox 0.4.0 (git+https://github.com/bekker/msgbox-rs.git?rev=68fe39a)",
  "num 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "rodio 0.9.0 (git+https://github.com/RustAudio/rodio?rev=e5474a2)",
+ "rodio 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ron 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rust-argon2 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.102 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3654,7 +3612,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum chunked_transfer 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "498d20a7aaf62625b9bf26e637cf7736417cde1d0c99f1d04d1170229a85cf87"
 "checksum clang-sys 0.28.1 (registry+https://github.com/rust-lang/crates.io-index)" = "81de550971c976f176130da4b2978d3b524eaa0fd9ac31f3ceb5ae1231fb4853"
 "checksum clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
-"checksum claxon 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f86c952727a495bda7abaf09bafdee1a939194dd793d9a8e26281df55ac43b00"
 "checksum clipboard-win 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e3a093d6fed558e5fe24c3dfc85a68bb68f1c824f440d3ba5aca189e2998786b"
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
 "checksum cocoa 0.18.5 (registry+https://github.com/rust-lang/crates.io-index)" = "1706996401131526e36b3b49f0c4d912639ce110996f3ca144d78946727bce54"
@@ -3782,7 +3739,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
 "checksum lz4-compress 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0f966533a922a9bba9e95e594c1fdb3b9bf5fdcdb11e37e51ad84cd76e468b91"
 "checksum lzw 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7d947cbb889ed21c2a84be6ffbaebf5b4e0f4340638cba0444907e38b56be084"
-"checksum mach 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "86dd2487cdfea56def77b88438a2c915fb45113c5319bfe7e14306ca4cd0b0e1"
 "checksum malloc_buf 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "62bb907fe88d54d8d9ce32a3cceab4218ed2f6b7d35617cafe9adf84e43919cb"
 "checksum matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 "checksum maybe-uninit 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "60302e4db3a61da70c0cb7991976248362f30319e88850c487b9b95bbf059e00"
@@ -3792,8 +3748,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum mime 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "ba626b8a6de5da682e1caa06bdb42a335aee5a84db8e5046a3e8ab17ba0a3ae0"
 "checksum mime_guess 1.8.7 (registry+https://github.com/rust-lang/crates.io-index)" = "0d977de9ee851a0b16e932979515c0f3da82403183879811bc97d50bd9cc50f7"
 "checksum minifb 0.13.0 (git+https://github.com/emoon/rust_minifb.git)" = "<none>"
-"checksum minimp3 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "542e9bed56860c5070a09939eee0e2df6f8f73f60304ddf56d620947e7017239"
-"checksum minimp3-sys 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c109ae05c00ad6e3a53fab101e2f234545bdd010f0fffd399355efaf70817817"
 "checksum mio 0.6.21 (registry+https://github.com/rust-lang/crates.io-index)" = "302dec22bcf6bae6dfb69c647187f4b4d0fb6f535521f7bc022430ce8e12008f"
 "checksum mio-extras 2.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "46e73a04c2fa6250b8d802134d56d554a9ec2922bf977777c805ea5def61ce40"
 "checksum miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
@@ -3888,7 +3842,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum regex-automata 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "92b73c2a1770c255c240eaa4ee600df1704a38dc3feaa6e949e7fcd4f8dc09f9"
 "checksum regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)" = "11a7e20d1cce64ef2fed88b66d347f88bd9babb82845b2b858f3edbf59a4f716"
 "checksum remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4a83fa3702a688b9359eccba92d153ac33fd2e8462f9e0e3fdf155239ea7792e"
-"checksum rodio 0.9.0 (git+https://github.com/RustAudio/rodio?rev=e5474a2)" = "<none>"
+"checksum rodio 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1e0e0dfa7c8b17c6428f6e992a22ea595922cc86f946191b6b59e7ce96b77262"
 "checksum ron 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2ece421e0c4129b90e4a35b6f625e472e96c552136f5093a2f4fa2bbb75a62d5"
 "checksum roots 0.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "e4c67c712ab62be58b24ab8960e2b95dd4ee00aac115c76f2709657821fe376d"
 "checksum rouille 3.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "112568052ec17fa26c6c11c40acbb30d3ad244bf3d6da0be181f5e7e42e5004f"
@@ -3919,7 +3873,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum shrev 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b5752e017e03af9d735b4b069f53b7a7fd90fefafa04d8bd0c25581b0bff437f"
 "checksum siphasher 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "0b8de496cf83d4ed58b6be86c3a275b8602f6ffe98d3024a869e124147a9a3ac"
 "checksum slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
-"checksum slice-deque 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "ffddf594f5f597f63533d897427a570dbaa9feabaaa06595b74b71b7014507d7"
 "checksum smallvec 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)" = "f7b0758c52e15a8b5e3691eae6cc559f08eee9406e548a4477ba4e67770a82b6"
 "checksum smallvec 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4ecf3b85f68e8abaa7555aa5abdb1153079387e60b718283d732f03897fcfc86"
 "checksum smithay-client-toolkit 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2ccb8c57049b2a34d2cc2b203fa785020ba0129d31920ef0d317430adaf748fa"

voxygen/Cargo.toml

@@ -55,8 +55,7 @@ num = "0.2.0"
 backtrace = "0.3.40"
 rand = "0.7.2"
 treeculler = { git = "https://gitlab.com/yusdacra/treeculler.git" }
-# context for pinning to commit: https://gitlab.com/veloren/veloren/issues/280
+rodio = { version = "0.10", default-features = false, features = ["wav", "vorbis"] }
-rodio = { git = "https://github.com/RustAudio/rodio", rev = "e5474a2"}
 cpal = "0.10"
 crossbeam = "=0.7.2"
 hashbrown = { version = "0.6.2", features = ["rayon", "serde", "nightly"] }

voxygen/src/audio/channel.rs

@@ -1,51 +1,125 @@
-use crate::audio::fader::Fader;
+use crate::audio::fader::{FadeDirection, Fader};
-use rodio::{Device, Sample, Source, SpatialSink};
+use rodio::{Device, Sample, Sink, Source, SpatialSink};
 use vek::*;
 
-#[derive(PartialEq, Clone, Copy)]
-pub enum AudioType {
-    Sfx,
-    Music,
-    None,
-}
-
 #[derive(PartialEq, Clone, Copy)]
 enum ChannelState {
-    // Init,
-    // ToPlay,
-    // Loading,
     Playing,
-    Stopping,
+    Fading,
     Stopped,
 }
 
+/// Each MusicChannel has a MusicChannelTag which help us determine how we
+/// should transition between music types
 #[derive(PartialEq, Clone, Copy)]
-pub enum ChannelTag {
+pub enum MusicChannelTag {
     TitleMusic,
-    Soundtrack,
+    Exploration,
 }
 
-pub struct Channel {
+/// A MusicChannel uses a non-positional audio sink designed to play music which
-    id: usize,
+/// is always heard at the player's position
-    sink: SpatialSink,
+pub struct MusicChannel {
-    audio_type: AudioType,
+    tag: MusicChannelTag,
+    sink: Sink,
     state: ChannelState,
     fader: Fader,
-    tag: Option<ChannelTag>,
+}
+
+impl MusicChannel {
+    pub fn new(device: &Device) -> Self {
+        Self {
+            sink: Sink::new(device),
+            tag: MusicChannelTag::TitleMusic,
+            state: ChannelState::Stopped,
+            fader: Fader::default(),
+        }
+    }
+
+    // Play a music track item on this channel. If the channel has an existing track
+    // playing, the new sounds will be appended and played once they complete.
+    // Otherwise it will begin playing immediately.
+    pub fn play<S>(&mut self, source: S, tag: MusicChannelTag)
+    where
+        S: Source + Send + 'static,
+        S::Item: Sample,
+        S::Item: Send,
+        <S as std::iter::Iterator>::Item: std::fmt::Debug,
+    {
+        self.tag = tag;
+        self.sink.append(source);
+
+        self.state = if !self.fader.is_finished() {
+            ChannelState::Fading
+        } else {
+            ChannelState::Playing
+        };
+    }
+
+    /// Set the volume of the current channel. If the channel is currently
+    /// fading, the volume of the fader is updated to this value.
+    pub fn set_volume(&mut self, volume: f32) {
+        if !self.fader.is_finished() {
+            self.fader.update_target_volume(volume);
+        } else {
+            self.sink.set_volume(volume);
+        }
+    }
+
+    /// Set a fader for the channel. If a fader exists already, it is replaced.
+    /// If the channel has not begun playing, and the fader is set to fade in,
+    /// we set the volume of the channel to the initial volume of the fader so
+    /// that the volumes match when playing begins.
+    pub fn set_fader(&mut self, fader: Fader) {
+        self.fader = fader;
+        self.state = ChannelState::Fading;
+
+        if self.state == ChannelState::Stopped && fader.direction() == FadeDirection::In {
+            self.sink.set_volume(fader.get_volume());
+        }
+    }
+
+    /// Returns true if either the channels sink reports itself as empty (no
+    /// more sounds in the queue) or we have forcibly set the channels state to
+    /// the 'Stopped' state
+    pub fn is_done(&self) -> bool { self.sink.empty() || self.state == ChannelState::Stopped }
+
+    pub fn get_tag(&self) -> MusicChannelTag { self.tag }
+
+    /// Maintain the fader attached to this channel. If the channel is not
+    /// fading, no action is taken.
+    pub fn maintain(&mut self, dt: f32) {
+        if self.state == ChannelState::Fading {
+            self.fader.update(dt);
+            self.sink.set_volume(self.fader.get_volume());
+
+            if self.fader.is_finished() {
+                match self.fader.direction() {
+                    FadeDirection::Out => {
+                        self.state = ChannelState::Stopped;
+                        self.sink.stop();
+                    },
+                    FadeDirection::In => {
+                        self.state = ChannelState::Playing;
+                    },
+                }
+            }
+        }
+    }
+}
+
+/// An SfxChannel uses a positional audio sink, and is designed for short-lived
+/// audio which can be spatially controlled, but does not need control over
+/// playback or fading/transitions
+pub struct SfxChannel {
+    sink: SpatialSink,
     pub pos: Vec3<f32>,
 }
 
-// TODO: Implement asynchronous loading
+impl SfxChannel {
-impl Channel {
-    /// Create an empty channel for future use
     pub fn new(device: &Device) -> Self {
         Self {
-            id: 0,
             sink: SpatialSink::new(device, [0.0; 3], [1.0, 0.0, 0.0], [-1.0, 0.0, 0.0]),
-            audio_type: AudioType::None,
-            state: ChannelState::Stopped,
-            fader: Fader::fade_in(0.0),
-            tag: None,
             pos: Vec3::zero(),
         }
     }
@@ -57,31 +131,13 @@ impl Channel {
         S::Item: Send,
         <S as std::iter::Iterator>::Item: std::fmt::Debug,
     {
-        self.state = ChannelState::Playing;
         self.sink.append(source);
     }
 
-    pub fn is_done(&self) -> bool { self.sink.empty() || self.state == ChannelState::Stopped }
-
-    pub fn set_tag(&mut self, tag: Option<ChannelTag>) { self.tag = tag; }
-
-    pub fn get_tag(&self) -> Option<ChannelTag> { self.tag }
-
-    pub fn stop(&mut self, fader: Fader) {
-        self.state = ChannelState::Stopping;
-        self.fader = fader;
-    }
-
-    pub fn get_id(&self) -> usize { self.id }
-
-    pub fn set_id(&mut self, new_id: usize) { self.id = new_id; }
-
-    pub fn get_audio_type(&self) -> AudioType { self.audio_type }
-
-    pub fn set_audio_type(&mut self, audio_type: AudioType) { self.audio_type = audio_type; }
-
     pub fn set_volume(&mut self, volume: f32) { self.sink.set_volume(volume); }
 
+    pub fn is_done(&self) -> bool { self.sink.empty() }
+
     pub fn set_emitter_position(&mut self, pos: [f32; 3]) { self.sink.set_emitter_position(pos); }
 
     pub fn set_left_ear_position(&mut self, pos: [f32; 3]) { self.sink.set_left_ear_position(pos); }
@@ -89,20 +145,4 @@ impl Channel {
     pub fn set_right_ear_position(&mut self, pos: [f32; 3]) {
         self.sink.set_right_ear_position(pos);
     }
-
-    pub fn update(&mut self, dt: f32) {
-        match self.state {
-            // ChannelState::Init | ChannelState::ToPlay | ChannelState::Loading => {}
-            ChannelState::Playing => {},
-            ChannelState::Stopping => {
-                self.fader.update(dt);
-                self.sink.set_volume(self.fader.get_volume());
-
-                if self.fader.is_finished() {
-                    self.state = ChannelState::Stopped;
-                }
-            },
-            ChannelState::Stopped => {},
-        }
-    }
 }

voxygen/src/audio/fader.rs

@@ -6,13 +6,18 @@ pub struct Fader {
     volume_to: f32,
     is_running: bool,
 }
+#[derive(Debug, PartialEq, Clone, Copy)]
+pub enum FadeDirection {
+    In,
+    Out,
+}
 
 fn lerp(t: f32, a: f32, b: f32) -> f32 { (1.0 - t) * a + t * b }
 
 impl Fader {
-    pub fn fade(time: f32, volume_from: f32, volume_to: f32) -> Self {
+    pub fn fade(length: f32, volume_from: f32, volume_to: f32) -> Self {
         Self {
-            length: time,
+            length,
             running_time: 0.0,
             volume_from,
             volume_to,
@@ -20,23 +25,28 @@ impl Fader {
         }
     }
 
-    pub fn fade_in(time: f32) -> Self {
+    pub fn fade_in(time: f32, volume_to: f32) -> Self { Self::fade(time, 0.0, volume_to) }
-        Self {
+
-            length: time,
+    pub fn fade_out(time: f32, volume_from: f32) -> Self { Self::fade(time, volume_from, 0.0) }
-            running_time: 0.0,
+
-            volume_from: 0.0,
+    pub fn update_target_volume(&mut self, volume: f32) {
-            volume_to: 1.0,
+        match self.direction() {
-            is_running: true,
+            FadeDirection::In => {
+                self.volume_to = volume;
+            },
+            FadeDirection::Out => {
+                if self.get_volume() > volume {
+                    self.volume_from = volume;
+                }
+            },
         }
     }
 
-    pub fn fade_out(time: f32, volume_from: f32) -> Self {
+    pub fn direction(&self) -> FadeDirection {
-        Self {
+        if self.volume_to < self.volume_from {
-            length: time,
+            FadeDirection::Out
-            running_time: 0.0,
+        } else {
-            volume_from,
+            FadeDirection::In
-            volume_to: 0.0,
-            is_running: true,
         }
     }
 
@@ -60,3 +70,107 @@ impl Fader {
 
     pub fn is_finished(&self) -> bool { self.running_time >= self.length || !self.is_running }
 }
+
+/// Returns a stopped fader with no running duration
+impl Default for Fader {
+    fn default() -> Self {
+        Self {
+            length: 0.0,
+            running_time: 0.0,
+            volume_from: 0.0,
+            volume_to: 1.0,
+            is_running: false,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn fade_direction_in() {
+        let fader = Fader::fade_in(10.0, 0.0);
+
+        assert_eq!(fader.direction(), FadeDirection::In);
+    }
+
+    #[test]
+    fn fade_direction_out() {
+        let fader = Fader::fade_out(10.0, 1.0);
+
+        assert_eq!(fader.direction(), FadeDirection::Out);
+    }
+
+    #[test]
+    fn fade_out_completes() {
+        let mut fader = Fader::fade_out(10.0, 1.0);
+
+        // Run for the full duration
+        fader.update(10.0);
+
+        assert_eq!(fader.get_volume(), 0.0);
+        assert!(fader.is_finished());
+    }
+
+    #[test]
+    fn update_target_volume_fading_out_when_currently_above() {
+        let mut fader = Fader::fade_out(20.0, 1.0);
+
+        // After 0.1s, the fader should still be close to 1.0
+        fader.update(0.1);
+
+        // Reduce volume to 0.4. We are currently above that.
+        fader.update_target_volume(0.4);
+
+        // The volume should immediately reduce to < 0.4 on the next update
+        fader.update(0.1);
+
+        assert!(fader.get_volume() < 0.4)
+    }
+
+    #[test]
+    fn update_target_volume_fading_out_when_currently_below() {
+        let mut fader = Fader::fade_out(10.0, 0.8);
+
+        // After 9s, the fader should be close to 0
+        fader.update(9.0);
+
+        // Notify of a volume increase to 1.0. We are already far below that.
+        fader.update_target_volume(1.0);
+
+        // The fader should be unaffected by the new value, and continue dropping
+        fader.update(0.1);
+
+        assert!(fader.get_volume() < 0.2);
+    }
+
+    #[test]
+    fn update_target_volume_fading_in_when_currently_above() {
+        let mut fader = Fader::fade_in(10.0, 1.0);
+
+        // After 9s, the fader should be close to 1.0
+        fader.update(9.0);
+
+        // Reduce volume to 0.4. We are currently above that.
+        fader.update_target_volume(0.4);
+
+        // Run out the fader. It's volume should be 0.4
+        fader.update(1.0);
+
+        assert_eq!(fader.get_volume(), 0.4);
+    }
+
+    #[test]
+    fn update_target_volume_fading_in_when_currently_below() {
+        let mut fader = Fader::fade_in(20.0, 1.0);
+
+        // After 0.1s, the fader should still be close to 0.0
+        fader.update(0.1);
+
+        // Reduce volume to 0.4. The volume_to should be reduced accordingly.
+        fader.update_target_volume(0.4);
+
+        assert_eq!(fader.volume_to, 0.4);
+    }
+}

voxygen/src/audio/mod.rs

@@ -4,7 +4,7 @@ pub mod music;
 pub mod sfx;
 pub mod soundcache;
 
-use channel::{AudioType, Channel, ChannelTag};
+use channel::{MusicChannel, MusicChannelTag, SfxChannel};
 use fader::Fader;
 use soundcache::SoundCache;
 
@@ -21,8 +21,8 @@ pub struct AudioFrontend {
     audio_device: Option<Device>,
     sound_cache: SoundCache,
 
-    channels: Vec<Channel>,
+    music_channels: Vec<MusicChannel>,
-    next_channel_id: usize,
+    sfx_channels: Vec<SfxChannel>,
 
     sfx_volume: f32,
     music_volume: f32,
@@ -36,21 +36,23 @@ pub struct AudioFrontend {
 
 impl AudioFrontend {
     /// Construct with given device
-    pub fn new(device: String, channel_num: usize) -> Self {
+    pub fn new(device: String, max_sfx_channels: usize) -> Self {
-        let mut channels = Vec::with_capacity(channel_num);
+        let mut sfx_channels = Vec::with_capacity(max_sfx_channels);
         let audio_device = get_device_raw(&device);
+
         if let Some(audio_device) = &audio_device {
-            for _i in 0..channel_num {
+            for _ in 0..max_sfx_channels {
-                channels.push(Channel::new(&audio_device));
+                sfx_channels.push(SfxChannel::new(&audio_device));
             }
         }
+
         Self {
             device: device.clone(),
             device_list: list_devices(),
             audio_device,
             sound_cache: SoundCache::new(),
-            channels,
+            music_channels: Vec::new(),
-            next_channel_id: 1,
+            sfx_channels,
             sfx_volume: 1.0,
             music_volume: 1.0,
             listener_pos: Vec3::zero(),
@@ -67,8 +69,8 @@ impl AudioFrontend {
             device_list: Vec::new(),
             audio_device: None,
             sound_cache: SoundCache::new(),
-            channels: Vec::new(),
+            music_channels: Vec::new(),
-            next_channel_id: 1,
+            sfx_channels: Vec::new(),
             sfx_volume: 1.0,
             music_volume: 1.0,
             listener_pos: Vec3::zero(),
@@ -78,40 +80,62 @@ impl AudioFrontend {
         }
     }
 
-    /// Maintain audio
+    /// Drop any unused music channels, and update their faders
     pub fn maintain(&mut self, dt: f32) {
-        for channel in self.channels.iter_mut() {
+        self.music_channels.retain(|c| !c.is_done());
-            channel.update(dt);
+
+        for channel in self.music_channels.iter_mut() {
+            channel.maintain(dt);
         }
     }
 
-    pub fn get_channel(
+    fn get_sfx_channel(&mut self) -> Option<&mut SfxChannel> {
+        if self.audio_device.is_some() {
+            if let Some(channel) = self.sfx_channels.iter_mut().find(|c| c.is_done()) {
+                channel.set_volume(self.sfx_volume);
+
+                return Some(channel);
+            }
+        }
+
+        None
+    }
+
+    /// Retrieve a music channel from the channel list. This inspects the
+    /// MusicChannelTag to determine whether we are transitioning between
+    /// music types and acts accordingly. For example transitioning between
+    /// `TitleMusic` and `Exploration` should fade out the title channel and
+    /// fade in a new `Exploration` channel.
+    fn get_music_channel(
         &mut self,
-        audio_type: AudioType,
+        next_channel_tag: MusicChannelTag,
-        channel_tag: Option<ChannelTag>,
+    ) -> Option<&mut MusicChannel> {
-    ) -> Option<&mut Channel> {
+        if let Some(audio_device) = &self.audio_device {
-        if let Some(channel) = self.channels.iter_mut().find(|c| c.is_done()) {
+            if self.music_channels.is_empty() {
-            let id = self.next_channel_id;
+                let mut next_music_channel = MusicChannel::new(&audio_device);
-            self.next_channel_id += 1;
+                next_music_channel.set_volume(self.music_volume);
 
-            let volume = match audio_type {
+                self.music_channels.push(next_music_channel);
-                AudioType::Music => self.music_volume,
+            } else {
-                _ => self.sfx_volume,
+                let existing_channel = self.music_channels.last_mut()?;
-            };
 
-            channel.set_id(id);
+                if existing_channel.get_tag() != next_channel_tag {
-            channel.set_tag(channel_tag);
+                    // Fade the existing channel out. It will be removed when the fade completes.
-            channel.set_audio_type(audio_type);
+                    existing_channel.set_fader(Fader::fade_out(2.0, self.music_volume));
-            channel.set_volume(volume);
 
-            Some(channel)
+                    let mut next_music_channel = MusicChannel::new(&audio_device);
-        } else {
+
-            None
+                    next_music_channel.set_fader(Fader::fade_in(12.0, self.music_volume));
+
+                    self.music_channels.push(next_music_channel);
+                }
+            }
         }
+
+        self.music_channels.last_mut()
     }
 
-    /// Play specfied sound file.
+    pub fn play_sfx(&mut self, sound: &str, pos: Vec3<f32>) {
-    pub fn play_sound(&mut self, sound: &str, pos: Vec3<f32>) -> Option<usize> {
         if self.audio_device.is_some() {
             let calc_pos = ((pos - self.listener_pos) * FALLOFF).into_array();
 
@@ -120,33 +144,22 @@ impl AudioFrontend {
             let left_ear = self.listener_ear_left.into_array();
             let right_ear = self.listener_ear_right.into_array();
 
-            if let Some(channel) = self.get_channel(AudioType::Sfx, None) {
+            if let Some(channel) = self.get_sfx_channel() {
                 channel.set_emitter_position(calc_pos);
                 channel.set_left_ear_position(left_ear);
                 channel.set_right_ear_position(right_ear);
                 channel.play(sound);
-
-                return Some(channel.get_id());
             }
         }
-
-        None
     }
 
-    pub fn play_music(&mut self, sound: &str, channel_tag: Option<ChannelTag>) -> Option<usize> {
+    fn play_music(&mut self, sound: &str, channel_tag: MusicChannelTag) {
-        if self.audio_device.is_some() {
+        if let Some(channel) = self.get_music_channel(channel_tag) {
-            if let Some(channel) = self.get_channel(AudioType::Music, channel_tag) {
+            let file = assets::load_file(&sound, &["ogg"]).expect("Failed to load sound");
-                let file = assets::load_file(&sound, &["ogg"]).expect("Failed to load sound");
+            let sound = Decoder::new(file).expect("Failed to decode sound");
-                let sound = Decoder::new(file).expect("Failed to decode sound");
 
-                channel.set_emitter_position([0.0; 3]);
+            channel.play(sound, channel_tag);
-                channel.play(sound);
-
-                return Some(channel.get_id());
-            }
         }
-
-        None
     }
 
     pub fn set_listener_pos(&mut self, pos: &Vec3<f32>, ori: &Vec3<f32>) {
@@ -161,8 +174,8 @@ impl AudioFrontend {
         self.listener_ear_left = pos_left;
         self.listener_ear_right = pos_right;
 
-        for channel in self.channels.iter_mut() {
+        for channel in self.sfx_channels.iter_mut() {
-            if !channel.is_done() && channel.get_audio_type() == AudioType::Sfx {
+            if !channel.is_done() {
                 // TODO: Update this to correctly determine the updated relative position of
                 // the SFX emitter when the player (listener) moves
                 // channel.set_emitter_position(
@@ -174,32 +187,18 @@ impl AudioFrontend {
         }
     }
 
-    pub fn play_title_music(&mut self) -> Option<usize> {
+    pub fn play_title_music(&mut self) {
         if self.music_enabled() {
             self.play_music(
                 "voxygen.audio.soundtrack.veloren_title_tune",
-                Some(ChannelTag::TitleMusic),
+                MusicChannelTag::TitleMusic,
             )
-        } else {
-            None
         }
     }
 
-    pub fn stop_title_music(&mut self) {
+    pub fn play_exploration_music(&mut self, item: &str) {
-        let index = self.channels.iter().position(|c| {
+        if self.music_enabled() {
-            !c.is_done() && c.get_tag().is_some() && c.get_tag().unwrap() == ChannelTag::TitleMusic
+            self.play_music(item, MusicChannelTag::Exploration)
-        });
-
-        if let Some(index) = index {
-            self.channels[index].stop(Fader::fade_out(1.5, self.music_volume));
-        }
-    }
-
-    pub fn stop_channel(&mut self, channel_id: usize, fader: Fader) {
-        let index = self.channels.iter().position(|c| c.get_id() == channel_id);
-
-        if let Some(index) = index {
-            self.channels[index].stop(fader);
         }
     }
 
@@ -214,24 +213,16 @@ impl AudioFrontend {
     pub fn set_sfx_volume(&mut self, sfx_volume: f32) {
         self.sfx_volume = sfx_volume;
 
-        for channel in self.channels.iter_mut() {
+        for channel in self.sfx_channels.iter_mut() {
-            if channel.get_audio_type() == AudioType::Sfx {
+            channel.set_volume(sfx_volume);
-                channel.set_volume(sfx_volume);
-            }
         }
     }
 
     pub fn set_music_volume(&mut self, music_volume: f32) {
         self.music_volume = music_volume;
 
-        for channel in self.channels.iter_mut() {
+        for channel in self.music_channels.iter_mut() {
-            if channel.get_audio_type() == AudioType::Music {
+            channel.set_volume(music_volume);
-                if music_volume > 0.0 {
-                    channel.set_volume(music_volume);
-                } else {
-                    channel.stop(Fader::fade_out(0.0, 0.0));
-                }
-            }
         }
     }
 

voxygen/src/audio/music.rs

@@ -1,4 +1,4 @@
-use crate::audio::{channel::ChannelTag, AudioFrontend};
+use crate::audio::AudioFrontend;
 use client::Client;
 use common::assets;
 use rand::{seq::IteratorRandom, thread_rng};
@@ -31,7 +31,6 @@ pub struct MusicMgr {
     soundtrack: SoundtrackCollection,
     began_playing: Instant,
     next_track_change: f64,
-    current_music: Option<usize>,
     last_track: String,
 }
 
@@ -41,7 +40,6 @@ impl MusicMgr {
             soundtrack: Self::load_soundtrack_items(),
             began_playing: Instant::now(),
             next_track_change: 0.0,
-            current_music: None,
             last_track: String::from("None"),
         }
     }
@@ -50,15 +48,15 @@ impl MusicMgr {
         if audio.music_enabled()
             && self.began_playing.elapsed().as_secs_f64() > self.next_track_change
         {
-            self.current_music = self.play_random_track(audio, client);
+            self.play_random_track(audio, client);
         }
     }
 
-    fn play_random_track(&mut self, audio: &mut AudioFrontend, client: &Client) -> Option<usize> {
+    fn play_random_track(&mut self, audio: &mut AudioFrontend, client: &Client) {
         const SILENCE_BETWEEN_TRACKS_SECONDS: f64 = 45.0;
 
         let game_time = (client.state().get_time_of_day() as u64 % 86400) as u32;
-        let current_period_of_day = self.get_current_day_period(game_time);
+        let current_period_of_day = Self::get_current_day_period(game_time);
         let mut rng = thread_rng();
 
         let track = self
@@ -79,10 +77,10 @@ impl MusicMgr {
         self.began_playing = Instant::now();
         self.next_track_change = track.length + SILENCE_BETWEEN_TRACKS_SECONDS;
 
-        audio.play_music(&track.path, Some(ChannelTag::Soundtrack))
+        audio.play_exploration_music(&track.path);
     }
 
-    fn get_current_day_period(&self, game_time: u32) -> DayPeriod {
+    fn get_current_day_period(game_time: u32) -> DayPeriod {
         if game_time > DAY_START_SECONDS && game_time < DAY_END_SECONDS {
             DayPeriod::Day
         } else {

voxygen/src/audio/sfx/mod.rs

@@ -91,7 +91,7 @@ impl SfxMgr {
                     },
                 };
 
-                audio.play_sound(sfx_file, position);
+                audio.play_sfx(sfx_file, position);
             }
         }
     }

voxygen/src/main.rs

@@ -121,7 +121,7 @@ fn main() {
     };
 
     let mut audio = if settings.audio.audio_on {
-        AudioFrontend::new(audio_device(), 16)
+        AudioFrontend::new(audio_device(), settings.audio.max_sfx_channels)
     } else {
         AudioFrontend::no_audio()
     };

voxygen/src/menu/main/mod.rs

@@ -18,7 +18,6 @@ use ui::{Event as MainMenuEvent, MainMenuUi};
 
 pub struct MainMenuState {
     main_menu_ui: MainMenuUi,
-    title_music_channel: Option<usize>,
     singleplayer: Option<Singleplayer>,
 }
 
@@ -27,7 +26,6 @@ impl MainMenuState {
     pub fn new(global_state: &mut GlobalState) -> Self {
         Self {
             main_menu_ui: MainMenuUi::new(global_state),
-            title_music_channel: None,
             singleplayer: None,
         }
     }
@@ -44,11 +42,8 @@ impl PlayState for MainMenuState {
         let mut client_init: Option<ClientInit> = None;
 
         // Kick off title music
-        if self.title_music_channel.is_none()
+        if global_state.settings.audio.audio_on && global_state.audio.music_enabled() {
-            && global_state.settings.audio.audio_on
+            global_state.audio.play_title_music();
-            && global_state.audio.music_enabled()
-        {
-            self.title_music_channel = global_state.audio.play_title_music();
         }
 
         // Reset singleplayer server if it was running already

voxygen/src/session.rs

@@ -126,9 +126,6 @@ impl PlayState for SessionState {
         let mut clock = Clock::start();
         self.client.borrow_mut().clear_terrain();
 
-        // Kill the title music if it is still playing
-        global_state.audio.stop_title_music();
-
         // Send startup commands to the server
         if global_state.settings.send_logon_commands {
             for cmd in &global_state.settings.logon_commands {

voxygen/src/settings.rs

@@ -221,6 +221,7 @@ pub struct AudioSettings {
     pub master_volume: f32,
     pub music_volume: f32,
     pub sfx_volume: f32,
+    pub max_sfx_channels: usize,
 
     /// Audio Device that Voxygen will use to play audio.
     pub audio_device: Option<String>,
@@ -233,6 +234,7 @@ impl Default for AudioSettings {
             master_volume: 1.0,
             music_volume: 0.4,
             sfx_volume: 0.6,
+            max_sfx_channels: 10,
             audio_device: None,
             audio_on: true,
         }