tweak stream loop behavior

src/FAudioGMS.c

@@ -175,7 +175,7 @@ typedef struct FAudioGMS_StaticSound
 } FAudioGMS_StaticSound;
 
 /* if we don't triple buffer, we'll microstutter the voice while waiting for decode */
-#define STREAMING_BUFFER_COUNT 3 
+#define STREAMING_BUFFER_COUNT 3
 #define DEFAULT_STREAMING_BUFFER_SIZE 32768
 
 typedef struct FAudioGMS_StreamingSound
@@ -187,7 +187,6 @@ typedef struct FAudioGMS_StreamingSound
     uint32_t nextStreamBufferIndex;  /* it's a ring buffer! */
     uint32_t buffersLoadedCount;     /* how many buffers are we buffering? */
     uint32_t mostRecentSampleOffset; /* used for calculating track position */
-    uint8_t isFinalBuffer;           /* used to detect end of playback */
 } FAudioGMS_StreamingSound;
 
 typedef struct FAudioGMS_SoundInstance FAudioGMS_SoundInstance;
@@ -358,23 +357,22 @@ static void FAudioGMS_INTERNAL_OnBufferEndCallback(
 
         instance->soundData.streamingSound.mostRecentSampleOffset %= instance->playLength;
 
-        if (instance->soundData.streamingSound.isFinalBuffer)
+        if (stb_vorbis_get_sample_offset(instance->soundData.streamingSound.fileHandle) >= stb_vorbis_stream_length_in_samples(instance->soundData.streamingSound.fileHandle))
         {
-            if (instance->loop)
+            FAudioGMS_INTERNAL_SoundInstance_Stop(instance);
-            {
-                stb_vorbis_seek(instance->soundData.streamingSound.fileHandle, instance->playBegin);
-                instance->soundData.streamingSound.mostRecentSampleOffset = instance->playBegin;
-                FAudioGMS_INTERNAL_SoundInstance_AddBuffers(instance);
-            }
-            else
-            {
-                FAudioGMS_INTERNAL_SoundInstance_Stop(instance);
-            }
         }
-        else
+        else if (instance->soundState != SoundState_Stopped)
         {
             FAudioGMS_INTERNAL_SoundInstance_AddBuffers(instance);
         }
+
+        /*
+        SDL_LogInfo(
+            SDL_LOG_CATEGORY_APPLICATION,
+            "instance ID: %p, current streaming buffer offset: %u",
+            instance,
+            instance->soundData.streamingSound.mostRecentSampleOffset);
+        */
     }
 
     if (instance->soundState == SoundState_Stopped)
@@ -1018,6 +1016,22 @@ static void FAudioGMS_INTERNAL_SoundInstance_AddBuffers(FAudioGMS_SoundInstance
                 .streamBuffer[instance->soundData.streamingSound.nextStreamBufferIndex],
             requestedSampleCount * instance->format.nChannels);
 
+        /* If the stream ran out and we need to loop, seek to beginning of play region and fill in the remaining samples */
+        if (instance->loop && sampleCount < defaultRequestedSampleCount)
+        {
+            uint32_t fillInSampleCount = defaultRequestedSampleCount - sampleCount;
+            stb_vorbis_seek(instance->soundData.streamingSound.fileHandle, instance->playBegin);
+
+            uint32_t remainingSampleCount = stb_vorbis_get_samples_float_interleaved(
+                instance->soundData.streamingSound.fileHandle,
+                instance->format.nChannels,
+                &instance->soundData.streamingSound
+                    .streamBuffer[instance->soundData.streamingSound.nextStreamBufferIndex][sampleCount * instance->format.nChannels],
+                fillInSampleCount * instance->format.nChannels);
+
+            sampleCount += remainingSampleCount;
+        }
+
         FAudioBuffer buffer;
         buffer.AudioBytes = sampleCount * instance->format.nChannels * sizeof(float);
         buffer.pAudioData =
@@ -1034,13 +1048,6 @@ static void FAudioGMS_INTERNAL_SoundInstance_AddBuffers(FAudioGMS_SoundInstance
 
         FAudioSourceVoice_SubmitSourceBuffer(instance->voice.handle, &buffer, NULL);
 
-        instance->soundData.streamingSound.isFinalBuffer = 0;
-
-        if (sampleCount < defaultRequestedSampleCount)
-        {
-            instance->soundData.streamingSound.isFinalBuffer = 1;
-        }
-
         instance->soundData.streamingSound.nextStreamBufferIndex =
             (instance->soundData.streamingSound.nextStreamBufferIndex + 1) % STREAMING_BUFFER_COUNT;
         instance->soundData.streamingSound.buffersLoadedCount += 1;
@@ -1081,14 +1088,11 @@ double FAudioGMS_StreamingSound_LoadOGG(char *filePath, double bufferSizeInBytes
 
     instance->soundData.streamingSound.streamBufferSize = bufferSizeInBytesInt;
     instance->soundData.streamingSound.mostRecentSampleOffset = 0;
-    instance->soundData.streamingSound.isFinalBuffer = 0;
     instance->soundData.streamingSound.nextStreamBufferIndex = 0;
     instance->soundData.streamingSound.buffersLoadedCount = 0;
 
     instance->playLength = stb_vorbis_stream_length_in_samples(fileHandle);
 
-    FAudioGMS_INTERNAL_SoundInstance_AddBuffers(instance);
-
     return instance->id;
 }
 
@@ -1181,6 +1185,10 @@ static void FAudioGMS_INTERNAL_SoundInstance_Play(FAudioGMS_SoundInstance *insta
             &instance->soundData.staticSound->buffer,
             NULL);
     }
+    else
+    {
+        FAudioGMS_INTERNAL_SoundInstance_AddBuffers(instance);
+    }
 
     FAudioSourceVoice_Start(instance->voice.handle, 0, 0);
     instance->soundState = SoundState_Playing;
@@ -1230,10 +1238,9 @@ static void FAudioGMS_INTERNAL_SoundInstance_Stop(FAudioGMS_SoundInstance *insta
 {
     if (instance != NULL)
     {
+        /* set before flush so we dont refill on OnBufferEnd callback */
         instance->soundState =
-            SoundState_Stopped; /* set this before so flush
+            SoundState_Stopped;
-                                                                               buffers
-                               doesn't trigger buffer add callback */
 
         FAudioSourceVoice_Stop(instance->voice.handle, 0, 0);
         FAudioSourceVoice_FlushSourceBuffers(instance->voice.handle);
@@ -1245,8 +1252,6 @@ static void FAudioGMS_INTERNAL_SoundInstance_Stop(FAudioGMS_SoundInstance *insta
             stb_vorbis_seek(
                 instance->soundData.streamingSound.fileHandle,
                 instance->playBegin); /* back to the start */
-            FAudioGMS_INTERNAL_SoundInstance_AddBuffers(
-                instance); /* preload so we dont stutter on play */
         }
     }
     else