Fix audio playback issues in some cases with XAudio backend

#675

Source/Engine/Audio/AudioSource.cpp

@@ -227,9 +227,11 @@ void AudioSource::Cleanup()
     _savedTime = GetTime();
     Stop();
 
-    AudioBackend::Source::Cleanup(this);
-
-    SourceIDs.Clear();
+    if (SourceIDs.HasItems())
+    {
+        AudioBackend::Source::Cleanup(this);
+        SourceIDs.Clear();
+    }
 }
 
 void AudioSource::OnClipChanged()
@@ -239,13 +241,10 @@ void AudioSource::OnClipChanged()
 
 void AudioSource::OnClipLoaded()
 {
-    if (SourceIDs.IsEmpty())
-        return;
-
     AudioBackend::Source::ClipLoaded(this);
 
     // Start playing if source was waiting for the clip to load
-    if (_state == States::Playing && !_isActuallyPlayingSth)
+    if (SourceIDs.HasItems() && _state == States::Playing && !_isActuallyPlayingSth)
     {
         if (Clip->IsStreamable())
         {

Source/Engine/Audio/XAudio2/AudioBackendXAudio2.cpp

@@ -230,6 +230,8 @@ namespace XAudio2
 
     Source* GetSource(const AudioSource* source)
     {
+        if (source->SourceIDs.Count() == 0)
+            return nullptr;
         const AUDIO_SOURCE_ID_TYPE sourceId = source->SourceIDs[0];
         // 0 is invalid ID so shift them
         return &Sources[sourceId - 1];
@@ -531,7 +533,7 @@ void AudioBackendXAudio2::Source_Cleanup(AudioSource* source)
 void AudioBackendXAudio2::Source_Play(AudioSource* source)
 {
     auto aSource = XAudio2::GetSource(source);
-    if (aSource && aSource->Voice)
+    if (aSource && aSource->Voice && !aSource->IsPlaying)
     {
         // Play
         aSource->Voice->Start();
@@ -542,7 +544,7 @@ void AudioBackendXAudio2::Source_Play(AudioSource* source)
 void AudioBackendXAudio2::Source_Pause(AudioSource* source)
 {
     auto aSource = XAudio2::GetSource(source);
-    if (aSource && aSource->Voice)
+    if (aSource && aSource->Voice && aSource->IsPlaying)
     {
         // Pause
         aSource->Voice->Stop();