Replace Sleep function with waitable event

src/win32/XAudio2.cpp

@@ -39,6 +39,27 @@
 #include "../Globals.h" // for 'speedup' and 'synchronize'
 
 
+// Synchronization Event
+class XAudio2_BufferNotify : public IXAudio2VoiceCallback
+{
+public:
+	HANDLE hBufferEndEvent;
+
+	XAudio2_BufferNotify() { hBufferEndEvent = CreateEvent( NULL, FALSE, FALSE, NULL ); }
+	~XAudio2_BufferNotify() { CloseHandle( hBufferEndEvent ); }
+
+    STDMETHOD_( void, OnBufferEnd ) ( void *pBufferContext ) { SetEvent( hBufferEndEvent ); }
+
+	// dummies:
+	STDMETHOD_( void, OnVoiceProcessingPassStart ) () {}
+	STDMETHOD_( void, OnVoiceProcessingPassEnd ) () {}
+	STDMETHOD_( void, OnStreamEnd ) () {}
+	STDMETHOD_( void, OnBufferStart ) ( void *pBufferContext ) {}
+	STDMETHOD_( void, OnLoopEnd ) ( void *pBufferContext ) {}
+	STDMETHOD_( void, OnVoiceError ) ( void *pBufferContext, HRESULT Error ) {};
+};
+
+
 // Class Declaration
 class XAudio2_Output
 	: public ISound
@@ -67,14 +88,15 @@ private:
 	bool   initialized;
 	bool   playing;
 	UINT32 freq;
-	BYTE   *buffers;
+	BYTE  *buffers;
 	int    currentBuffer;
 
 	IXAudio2               *xaud;
-	IXAudio2MasteringVoice *mVoice; // dest
-	IXAudio2SourceVoice    *sVoice; // source
+	IXAudio2MasteringVoice *mVoice; // listener
+	IXAudio2SourceVoice    *sVoice; // sound source
 	XAUDIO2_BUFFER          buf;
 	XAUDIO2_VOICE_STATE     vState;
+	XAudio2_BufferNotify    notify; // buffer end notification
 };
 
 
@@ -85,7 +107,7 @@ XAudio2_Output::XAudio2_Output()
 	initialized = false;
 	playing = false;
 	freq = 0;
-	buffers = 0;
+	buffers = NULL;
 	currentBuffer = 0;
 
 	xaud = NULL;
@@ -181,7 +203,7 @@ bool XAudio2_Output::init()
 
 
 	// Create Sound Emitter
-	hr = xaud->CreateSourceVoice( &sVoice, &wfx, 0, XAUDIO2_MAX_FREQ_RATIO );
+	hr = xaud->CreateSourceVoice( &sVoice, &wfx, 0, 4.0f, &notify );
 
 	if( FAILED( hr ) ) {
 		systemMessage( IDS_XAUDIO2_CANNOT_CREATE_SOURCEVOICE, NULL );
@@ -203,7 +225,25 @@ void XAudio2_Output::write()
 {
 	if( !initialized || failed ) return;
 
-	bool drop = false;
+	while( true ) {
+		sVoice->GetState( &vState );
+
+		ASSERT( vState.BuffersQueued <= NBUFFERS );
+
+		if( vState.BuffersQueued < NBUFFERS ) {
+			// there is at least one free buffer
+			break;
+		} else {
+			// the maximum number of buffers is currently queued
+			if( synchronize && !speedup && !theApp.throttle ) {
+				// wait for one buffer to finish playing
+				WaitForSingleObject( notify.hBufferEndEvent, INFINITE );
+			} else {
+				// drop current audio frame
+				return;
+			}
+		}
+	}
 
 	// copy & protect the audio data in own memory area while playing it
 	CopyMemory( &buffers[ currentBuffer * soundBufferLen ], soundFinalWave, soundBufferLen );
@@ -214,32 +254,7 @@ void XAudio2_Output::write()
 	currentBuffer++;
 	currentBuffer %= ( NBUFFERS + 1 );
 
-	while( true ) {
-		sVoice->GetState( &vState );
-		ASSERT( vState.BuffersQueued <= NBUFFERS );
-
-		if( vState.BuffersQueued == NBUFFERS ) {
-			// all buffers filled
-			if( speedup || !synchronize || theApp.throttle ) {
-				drop = true;
-				break;
-			}
-
-			if( synchronize ) {
-				// wait for about half the time one buffer needs to finish
-				// unoptimized: ( sourceBufferLen * 1000 ) / ( freq * 2 * 2 ) * 1/2
-				Sleep( soundBufferLen / ( freq >> 7 ) );
-			}
-		} else {
-			// still room for new audio
-			break;
-		}
-	}
-
-	if( !drop ) {
-		// add the sound buffer to the queue
-		sVoice->SubmitSourceBuffer( &buf );
-	}
+	sVoice->SubmitSourceBuffer( &buf ); // send buffer to queue
 }
 
 
@@ -281,6 +296,8 @@ void XAudio2_Output::reset()
 
 void XAudio2_Output::setThrottle( unsigned short throttle )
 {
+	if( !initialized || failed ) return;
+
 	if( throttle == 0 ) throttle = 100;
 	sVoice->SetFrequencyRatio( (float)throttle / 100.0f );
 }