From 325721e4d1bd1b13781f12a157a67eacac000500 Mon Sep 17 00:00:00 2001
From: Zicklag <zicklag@katharostech.com>
Date: Thu, 19 Oct 2023 12:25:51 -0500
Subject: [PATCH] fix: fallback to dummy audio backend if the real audio
 backend fails.

---
 .../bones_framework/src/render/audio.rs       | 46 +++++++++++++++++--
 1 file changed, 43 insertions(+), 3 deletions(-)

diff --git a/framework_crates/bones_framework/src/render/audio.rs b/framework_crates/bones_framework/src/render/audio.rs
index eb6a75dc52..f6b7e96fc8 100644
--- a/framework_crates/bones_framework/src/render/audio.rs
+++ b/framework_crates/bones_framework/src/render/audio.rs
@@ -6,7 +6,10 @@ use crate::prelude::*;
 
 pub use kira::{self, sound::static_sound::StaticSoundData};
 use kira::{
-    manager::{backend::cpal::CpalBackend, AudioManager as KiraAudioManager},
+    manager::{
+        backend::{cpal::CpalBackend, mock::MockBackend, Backend},
+        AudioManager as KiraAudioManager,
+    },
     sound::SoundData,
 };
 
@@ -20,10 +23,47 @@ pub fn game_plugin(game: &mut Game) {
 /// The audio manager resource which can be used to play sounds.
 #[derive(HasSchema, Deref, DerefMut)]
 #[schema(no_clone)]
-pub struct AudioManager(KiraAudioManager);
+pub struct AudioManager(KiraAudioManager<CpalWithFallbackBackend>);
 impl Default for AudioManager {
     fn default() -> Self {
-        Self(KiraAudioManager::<CpalBackend>::new(default()).unwrap())
+        Self(KiraAudioManager::<CpalWithFallbackBackend>::new(default()).unwrap())
+    }
+}
+
+/// Kira audio backend that will fall back to a dummy backend if setting up the Cpal backend
+/// fails with an error.
+#[allow(clippy::large_enum_variant)]
+pub enum CpalWithFallbackBackend {
+    /// This is a working Cpal backend.
+    Cpal(CpalBackend),
+    /// This is a dummy backend since Cpal didn't work.
+    Dummy(MockBackend),
+}
+
+impl Backend for CpalWithFallbackBackend {
+    type Settings = <CpalBackend as Backend>::Settings;
+    type Error = <CpalBackend as Backend>::Error;
+
+    fn setup(settings: Self::Settings) -> Result<(Self, u32), Self::Error> {
+        match CpalBackend::setup(settings) {
+            Ok((back, bit)) => Ok((Self::Cpal(back), bit)),
+            Err(e) => {
+                tracing::error!("Error starting audio backend, using dummy backend instead: {e}");
+                Ok(MockBackend::setup(default())
+                    .map(|(back, bit)| (Self::Dummy(back), bit))
+                    .unwrap())
+            }
+        }
+    }
+
+    fn start(&mut self, renderer: kira::manager::backend::Renderer) -> Result<(), Self::Error> {
+        match self {
+            CpalWithFallbackBackend::Cpal(cpal) => cpal.start(renderer),
+            CpalWithFallbackBackend::Dummy(dummy) => {
+                dummy.start(renderer).unwrap();
+                Ok(())
+            }
+        }
     }
 }