From e3cdf3ab3855c7d372623205fac65491629bf166 Mon Sep 17 00:00:00 2001
From: Dan Spencer <dan@atomicpotato.net>
Date: Thu, 27 Nov 2014 00:54:51 -0700
Subject: [PATCH] Audio callback sends silence in case of Task panic

---
 src/sdl2/audio.rs | 42 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 34 insertions(+), 8 deletions(-)

diff --git a/src/sdl2/audio.rs b/src/sdl2/audio.rs
index 1a26dce4..8bfae491 100644
--- a/src/sdl2/audio.rs
+++ b/src/sdl2/audio.rs
@@ -282,19 +282,40 @@ impl Drop for AudioCallbackTask {
 /// All format types are returned as native-endian.
 ///
 /// Example: `assert_eq!(AudioFormatNum::<f32>::get_audio_format(), ll::AUDIO_F32);``
-pub trait AudioFormatNum<T> { fn get_audio_format() -> ll::SDL_AudioFormat; }
+pub trait AudioFormatNum<T> {
+    fn get_audio_format() -> ll::SDL_AudioFormat;
+    fn zero() -> Self;
+}
 /// AUDIO_S8
-impl AudioFormatNum<i8> for i8 { fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_S8 } }
+impl AudioFormatNum<i8> for i8 {
+    fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_S8 }
+    fn zero() -> i8 { 0 }
+}
 /// AUDIO_U8
-impl AudioFormatNum<u8> for u8 { fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_U8 } }
+impl AudioFormatNum<u8> for u8 {
+    fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_U8 }
+    fn zero() -> u8 { 0 }
+}
 /// AUDIO_S16
-impl AudioFormatNum<i16> for i16 { fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_S16SYS } }
+impl AudioFormatNum<i16> for i16 {
+    fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_S16SYS }
+    fn zero() -> i16 { 0 }
+}
 /// AUDIO_U16
-impl AudioFormatNum<u16> for u16 { fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_U16SYS } }
+impl AudioFormatNum<u16> for u16 {
+    fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_U16SYS }
+    fn zero() -> u16 { 0 }
+}
 /// AUDIO_S32
-impl AudioFormatNum<i32> for i32 { fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_S32SYS } }
+impl AudioFormatNum<i32> for i32 {
+    fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_S32SYS }
+    fn zero() -> i32 { 0 }
+}
 /// AUDIO_F32
-impl AudioFormatNum<f32> for f32 { fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_F32SYS } }
+impl AudioFormatNum<f32> for f32 {
+    fn get_audio_format() -> ll::SDL_AudioFormat { ll::AUDIO_F32SYS }
+    fn zero() -> f32 { 0.0 }
+}
 
 extern "C" fn audio_callback_marshall<T: AudioFormatNum<T>, CB: AudioCallback<T>>
 (userdata: *const c_void, stream: *const uint8_t, len: c_int) {
@@ -317,7 +338,12 @@ extern "C" fn audio_callback_marshall<T: AudioFormatNum<T>, CB: AudioCallback<T>
                 if n.is_destroyed() { None }
                 else { Some(n) }
             },
-            None => None
+            None => {
+                // Last callback had an error. Fill buffer with silence.
+                for x in buf.iter_mut() { *x = AudioFormatNum::zero(); }
+
+                None
+            }
         };
 
         replace(&mut cb_userdata.task.task, new_task);