1 files changed, 50 insertions, 5 deletions

diff --git a/src/audio/audio.cc b/src/audio/audio.cc
index de1c702..3b7b7fd 100644
--- a/src/audio/audio.cc
+++ b/src/audio/audio.cc
@@ -17,6 +17,12 @@
 // Global ring buffer for audio streaming
 static AudioRingBuffer g_ring_buffer;
 
+// Pending write buffer for partially written samples
+// Maximum size: one chunk (533 frames @ 60fps = 1066 samples stereo)
+#define MAX_PENDING_SAMPLES 2048
+static float g_pending_buffer[MAX_PENDING_SAMPLES];
+static int g_pending_samples = 0;  // How many samples are waiting to be written
+
 // Global backend pointer for audio abstraction
 static AudioBackend* g_audio_backend = nullptr;
 static MiniaudioBackend g_default_backend;
@@ -54,6 +60,9 @@ int register_spec_asset(AssetId id) {
 void audio_init() {
   synth_init();
 
+  // Clear pending buffer
+  g_pending_samples = 0;
+
   // Use default backend if none set
   if (g_audio_backend == nullptr) {
     g_audio_backend = &g_default_backend;
@@ -85,6 +94,31 @@ void audio_render_ahead(float music_time, float dt) {
 
   // Keep rendering small chunks until buffer is full enough
   while (true) {
+    // First, try to flush any pending samples from previous partial writes
+    if (g_pending_samples > 0) {
+      const int written = g_ring_buffer.write(g_pending_buffer, g_pending_samples);
+
+      if (written > 0) {
+        // Some or all samples were written
+        // Move remaining samples to front of buffer
+        const int remaining = g_pending_samples - written;
+        if (remaining > 0) {
+          for (int i = 0; i < remaining; ++i) {
+            g_pending_buffer[i] = g_pending_buffer[written + i];
+          }
+        }
+        g_pending_samples = remaining;
+
+        // Notify backend
+        if (g_audio_backend != nullptr) {
+          g_audio_backend->on_frames_rendered(written / RING_BUFFER_CHANNELS);
+        }
+      }
+
+      // If still have pending samples, buffer is full - wait for consumption
+      if (g_pending_samples > 0) break;
+    }
+
     // Check current buffer state
     const int buffered_samples = g_ring_buffer.available_read();
     const float buffered_time =
@@ -93,7 +127,7 @@ void audio_render_ahead(float music_time, float dt) {
     // Stop if buffer is full enough
     if (buffered_time >= target_lookahead) break;
 
-    // Check if buffer has space for this chunk BEFORE rendering
+    // Check if buffer has space for this chunk
     const int available_space = g_ring_buffer.available_write();
     if (available_space < chunk_samples) {
       // Buffer is too full, wait for audio callback to consume more
@@ -106,17 +140,28 @@ void audio_render_ahead(float music_time, float dt) {
     // Render audio from synth (advances synth state incrementally)
     synth_render(temp_buffer, chunk_frames);
 
-    // Write to ring buffer (should succeed since we checked space)
+    // Write to ring buffer
     const int written = g_ring_buffer.write(temp_buffer, chunk_samples);
 
-    // Notify backend of frames rendered (for testing/tracking)
+    // If partial write, save remaining samples to pending buffer
+    if (written < chunk_samples) {
+      const int remaining = chunk_samples - written;
+      if (remaining <= MAX_PENDING_SAMPLES) {
+        for (int i = 0; i < remaining; ++i) {
+          g_pending_buffer[i] = temp_buffer[written + i];
+        }
+        g_pending_samples = remaining;
+      }
+    }
+
+    // Notify backend of frames rendered (count frames sent to synth)
     if (g_audio_backend != nullptr) {
-      g_audio_backend->on_frames_rendered(written / RING_BUFFER_CHANNELS);
+      g_audio_backend->on_frames_rendered(chunk_frames);
     }
 
     delete[] temp_buffer;
 
-    // Safety: if write failed unexpectedly, stop to avoid infinite loop
+    // If we couldn't write everything, stop and retry next frame
     if (written < chunk_samples) break;
   }
 }