From c5e2cdd3c5d551541929069faa7f5b26c59e8cac Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Thu, 10 Sep 2015 21:03:40 +0200
Subject: [PATCH] Add an underflow() method to Voice

---
 src/alsa/mod.rs     |  4 ++++
 src/lib.rs          |  6 ++++++
 src/null/mod.rs     |  4 ++++
 src/wasapi/voice.rs | 10 ++++++++++
 4 files changed, 24 insertions(+)

diff --git a/src/alsa/mod.rs b/src/alsa/mod.rs
index 2e9dbe1..7bd77ff 100644
--- a/src/alsa/mod.rs
+++ b/src/alsa/mod.rs
@@ -107,6 +107,10 @@ impl Voice {
     pub fn pause(&mut self) {
         unimplemented!()
     }
+
+    pub fn underflowed(&self) -> bool {
+        false       // TODO: 
+    }
 }
 
 unsafe impl Send for Voice {}
diff --git a/src/lib.rs b/src/lib.rs
index 7e77b94..dfec780 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -339,6 +339,12 @@ impl Voice {
     pub fn pause(&mut self) {
         self.0.pause()
     }
+
+    /// Returns true if the voice has finished reading all the data you sent to it.
+    #[inline]
+    pub fn underflowed(&self) -> bool {
+        self.0.underflowed()
+    }
 }
 
 impl<'a, T> Deref for Buffer<'a, T> where T: Sample {
diff --git a/src/null/mod.rs b/src/null/mod.rs
index ff5e1db..866276e 100644
--- a/src/null/mod.rs
+++ b/src/null/mod.rs
@@ -70,6 +70,10 @@ impl Voice {
 
     pub fn pause(&mut self) {
     }
+
+    pub fn underflowed(&self) -> bool {
+        false
+    }
 }
 
 pub struct Buffer<'a, T: 'a> {
diff --git a/src/wasapi/voice.rs b/src/wasapi/voice.rs
index f8abb04..2a7d309 100644
--- a/src/wasapi/voice.rs
+++ b/src/wasapi/voice.rs
@@ -296,6 +296,16 @@ impl Voice {
 
         self.playing = false;
     }
+
+    pub fn underflowed(&self) -> bool {
+        unsafe {
+            let mut padding = mem::uninitialized();
+            let hresult = (*self.audio_client).GetCurrentPadding(&mut padding);
+            check_result(hresult).unwrap();
+            
+            padding == 0
+        }
+    }
 }
 
 impl Drop for Voice {