From 8c8d481dcf1b768dd7f9bf1acea781b6e7235d8c Mon Sep 17 00:00:00 2001
From: cosmonaut <evan@moonside.games>
Date: Wed, 3 Nov 2021 12:07:31 -0700
Subject: [PATCH] fix track position calculation on streaming audio

---
 src/FAudioGMS.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/FAudioGMS.c b/src/FAudioGMS.c
index 2e23a34..83ae79c 100644
--- a/src/FAudioGMS.c
+++ b/src/FAudioGMS.c
@@ -175,6 +175,7 @@ typedef struct FAudioGMS_StreamingSound
     stb_vorbis_info info;
     float* streamBuffer;
     uint32_t streamBufferSize;
+    uint32_t mostRecentBufferOffset; /* used for calculating track position */
 } FAudioGMS_StreamingSound;
 
 typedef struct FAudioGMS_SoundInstance
@@ -861,6 +862,8 @@ static void FAudioGMS_INTERNAL_SoundInstance_AddBuffer(FAudioGMS_SoundInstance*
 		instance->soundData.streamingSound.streamBufferSize = requiredStagingBufferSize;
     }
 
+    instance->soundData.streamingSound.mostRecentBufferOffset = stb_vorbis_get_sample_offset(instance->soundData.streamingSound.fileHandle);
+
     /* NOTE: this function returns samples per channel, not total samples */
     uint32_t sampleCount = stb_vorbis_get_samples_float_interleaved(
         instance->soundData.streamingSound.fileHandle,
@@ -927,6 +930,7 @@ double FAudioGMS_StreamingSound_LoadOGG(char* filePath)
     instance->soundData.streamingSound.info = info;
     instance->soundData.streamingSound.streamBuffer = NULL;
     instance->soundData.streamingSound.streamBufferSize = 0;
+    instance->soundData.streamingSound.mostRecentBufferOffset = 0;
 
     FAudioGMS_INTERNAL_SoundInstance_AddBuffer(instance);
 
@@ -1279,8 +1283,15 @@ double FAudioGMS_SoundInstance_GetTrackPositionInSeconds(double soundInstanceID)
 
     if (instance != NULL)
     {
-        uint32_t sampleFrame = instance->voice.handle->src.curBufferOffset / sizeof(float);
-        return sampleFrame / instance->format.nSamplesPerSec;
+        if (instance->isStatic)
+        {
+            uint32_t sampleFrame = instance->voice.handle->src.curBufferOffset / sizeof(float);
+            return sampleFrame / instance->format.nSamplesPerSec;
+        }
+        else
+        {
+            return ((double)instance->soundData.streamingSound.mostRecentBufferOffset + instance->voice.handle->src.curBufferOffset) / instance->format.nSamplesPerSec;
+        }
     }
     else
     {