1 files changed, 38 insertions, 5 deletions
diff --git a/reduced_system_layer.c b/reduced_system_layer.c
index dfc8b4f..bbb2a87 100755
--- a/reduced_system_layer.c
+++ b/reduced_system_layer.c
@@ -944,7 +944,6 @@ void p_handle_audio(i64 samples_elapsed) {
       fprintf(stderr, "%s:%d, %s: snd_pcm_writei failed: %s\n", __FILE__, __LINE__, __func__, snd_strerror(s));
 
     memset(_sound_ring + _sound_position, 0, num_frames);
-    _sound_position += num_frames;
   } else {
     i64 part_one = MAX_NUM_AUDIO_FRAMES - _sound_position;
     i64 part_two = num_frames - part_one;
@@ -959,8 +958,9 @@ void p_handle_audio(i64 samples_elapsed) {
 
     memset(_sound_ring + _sound_position, 0, part_one);
     memset(_sound_ring, 0, part_two);
-    _sound_position = part_two;
   }
+
+  _sound_position = (_sound_position + num_frames) % MAX_NUM_AUDIO_FRAMES;
 }
 
 void p_queue_sound(i64 delay_in_samples, i64 num_samples, f32 *frames) {
@@ -1685,8 +1685,15 @@ __attribute__((export_name("js_keyup"))) void js_keyup(u32 key, u32 mod) {
 
 #ifdef __wasm__
 
+i64 _sound_write                      = 0;
+i64 _sound_position                   = 0;
+f32 _sound_ring[MAX_NUM_AUDIO_FRAMES] = {0};
+
 void p_handle_audio(i64 samples_elapsed) {
-  //  TODO
+  if (samples_elapsed <= 0)
+    return;
+
+  _sound_write = (_sound_write + samples_elapsed * AUDIO_NUM_CHANNELS) % MAX_NUM_AUDIO_FRAMES;
 }
 
 void p_queue_sound(i64 delay_in_samples, i64 num_samples, f32 *frames) {
@@ -1701,12 +1708,38 @@ __attribute__((export_name("js_num_channels"))) i32 js_num_channels(void) {
   return AUDIO_NUM_CHANNELS;
 }
 
+__attribute__((export_name("js_max_num_audio_frames"))) i32 js_max_num_audio_frames(void) {
+  return MAX_NUM_AUDIO_FRAMES;
+}
+
 __attribute__((export_name("js_sound_buffer"))) void *js_sound_buffer(void) {
   return NULL;
 }
 
-__attribute__((export_name("js_sound_playback"))) void js_sound_playback(i64 num_samples) {
-  //  TODO
+__attribute__((export_name("js_sound_sync"))) i64 js_sound_sync(void) {
+  _sound_write    = AUDIO_AVAIL_MIN;
+  _sound_position = 0;
+  for (i64 i = 0; i < MAX_NUM_AUDIO_FRAMES; ++i)
+    _sound_ring[i] = 0.f;
+}
+
+__attribute__((export_name("js_sound_playback"))) i64 js_sound_playback(i64 num_samples) {
+  i64 position   = _sound_position;
+  i64 num_frames = AUDIO_NUM_CHANNELS * num_samples;
+
+  if (_sound_position + num_frames <= MAX_NUM_AUDIO_FRAMES) {
+    for (i64 i = _sound_position; i < _sound_position + num_frames; ++i)
+      _sound_ring[i] = 0.f;
+  } else {
+    for (i64 i = _sound_position; i < MAX_NUM_AUDIO_FRAMES; ++i)
+      _sound_ring[i] = 0.f;
+    i64 i_end = _sound_position + num_frames - MAX_NUM_AUDIO_FRAMES;
+    for (i64 i = 0; i < i_end; ++i)
+      _sound_ring[i] = 0.f;
+  }
+
+  _sound_position = (_sound_position + num_frames) % MAX_NUM_AUDIO_FRAMES;
+  return position;
 }
 
 #endif // __wasm__