Require user interaction to start audio

lightningbeam-core/src/audio.rs

@@ -3,6 +3,11 @@ use cpal::{Sample};
 use std::sync::{Arc, Mutex};
 use crate::{TrackManager, Timestamp, Duration, SampleCount, AudioOutput, PlaybackState};
 
+#[derive(PartialEq)]
+enum AudioState {
+    Suspended,
+    Running,
+}
 
 // #[cfg(feature = "wasm")]
 // use wasm_bindgen::prelude::*;
@@ -13,6 +18,7 @@ pub struct CpalAudioOutput {
   track_manager: Option<Arc<Mutex<TrackManager>>>,
   _stream: Option<cpal::Stream>,
   playback_state: PlaybackState,
+  audio_state: AudioState,
   timestamp: Arc<Mutex<Timestamp>>,
   chunk_size: usize,
   sample_rate: u32,
@@ -26,6 +32,7 @@ impl CpalAudioOutput {
       track_manager: None,
       _stream: None,
       playback_state: PlaybackState::Stopped,
+      audio_state: AudioState::Suspended,
       timestamp: Arc::new(Mutex::new(Timestamp::from_seconds(0.0))),
       chunk_size: 0,
       sample_rate: 44100, // Default sample rate, updated later
@@ -110,11 +117,6 @@ impl AudioOutput for CpalAudioOutput {
     .ok_or_else(|| "No output device available")?;
     let supported_config = device.default_output_config()?;
     self._stream = Some(self.build_stream::<f32>(&device, supported_config)?);
-    if let Some(stream) = self._stream.as_ref() {
-      stream.play().unwrap();
-    } else {
-      eprintln!("Stream is not initialized!");
-    }
     Ok(())
   }
   
@@ -127,6 +129,17 @@ impl AudioOutput for CpalAudioOutput {
     self.playback_state = PlaybackState::Stopped;
   }
 
+  fn resume(&mut self) -> Result<(), anyhow::Error> {
+    if self.audio_state == AudioState::Suspended {
+      if let Some(stream) = &self._stream {
+        stream.play()?;
+        self.audio_state = AudioState::Running;
+        log::info!("Audio resumed");
+      }
+    }
+    Ok(())
+  }
+  
   fn register_track_manager(&mut self, track_manager: Arc<Mutex<TrackManager>>) {
     self.track_manager = Some(track_manager);
   }

lightningbeam-core/src/lib.rs

@@ -95,6 +95,7 @@ pub trait AudioOutput {
   fn start(&mut self) -> Result<(), Box<dyn std::error::Error>>;
   fn play(&mut self, start_timestamp: Timestamp);
   fn stop(&mut self);
+  fn resume(&mut self) -> Result<(), anyhow::Error>;
   fn register_track_manager(&mut self, track_manager: Arc<Mutex<TrackManager>>);
   fn get_timestamp(&mut self) -> Timestamp;
   fn set_chunk_size(&mut self, chunk_size: usize);
@@ -218,6 +219,11 @@ impl CoreInterface {
     let mut track_manager = self.track_manager.lock().unwrap();
     track_manager.stop();
   }
+  pub fn resume_audio(&mut self) -> Result<(), JsValue> {
+    // Call this on user gestures if audio gets suspended
+    self.cpal_audio_output.resume()
+        .map_err(|e| JsValue::from_str(&format!("Failed to resume audio: {}", e)))
+  }
   pub fn add_sine_track(&mut self, frequency: f32) -> Result<(), String> {
     if frequency.is_nan() || frequency.is_infinite() || frequency <= 0.0 {
       return Err(format!("Invalid frequency: {}", frequency));

src/main.js

@@ -8419,5 +8419,26 @@ async function testAudio() {
   coreInterface.init()
   coreInterface.play(0.0)
   console.log(coreInterface)
+
+  let audioStarted = false;
+  const startCoreInterfaceAudio = () => {
+    if (!audioStarted) {
+      try {
+        coreInterface.resume_audio();
+        audioStarted = true;
+        console.log("Started CoreInterface Audio!")
+      } catch (err) {
+        console.error("Audio resume failed:", err);
+      }
+    }
+
+    // Remove the event listeners to prevent them from firing again
+    document.removeEventListener("click", startCoreInterfaceAudio);
+    document.removeEventListener("keydown", startCoreInterfaceAudio);
+  };
+
+  // Add event listeners for mouse click and key press
+  document.addEventListener("click", startCoreInterfaceAudio);
+  document.addEventListener("keydown", startCoreInterfaceAudio);
 }
 testAudio()

src/pkg/lightningbeam_core.d.ts

@@ -7,6 +7,7 @@ export class CoreInterface {
   init(): void;
   play(timestamp: number): void;
   stop(): void;
+  resume_audio(): void;
   add_sine_track(frequency: number): void;
   get_timestamp(): number;
   get_tracks(): JsTrack[];
@@ -30,6 +31,7 @@ export interface InitOutput {
   readonly coreinterface_init: (a: number) => void;
   readonly coreinterface_play: (a: number, b: number) => void;
   readonly coreinterface_stop: (a: number) => void;
+  readonly coreinterface_resume_audio: (a: number, b: number) => void;
   readonly coreinterface_add_sine_track: (a: number, b: number, c: number) => void;
   readonly coreinterface_get_timestamp: (a: number) => number;
   readonly coreinterface_get_tracks: (a: number, b: number) => void;

src/pkg/lightningbeam_core.js

@@ -288,6 +288,19 @@ export class CoreInterface {
     stop() {
         wasm.coreinterface_stop(this.__wbg_ptr);
     }
+    resume_audio() {
+        try {
+            const retptr = wasm.__wbindgen_add_to_stack_pointer(-16);
+            wasm.coreinterface_resume_audio(retptr, this.__wbg_ptr);
+            var r0 = getDataViewMemory0().getInt32(retptr + 4 * 0, true);
+            var r1 = getDataViewMemory0().getInt32(retptr + 4 * 1, true);
+            if (r1) {
+                throw takeObject(r0);
+            }
+        } finally {
+            wasm.__wbindgen_add_to_stack_pointer(16);
+        }
+    }
     /**
      * @param {number} frequency
      */
@@ -549,8 +562,8 @@ function __wbg_get_imports() {
         const ret = false;
         return ret;
     };
-    imports.wbg.__wbindgen_closure_wrapper99 = function(arg0, arg1, arg2) {
-        const ret = makeMutClosure(arg0, arg1, 40, __wbg_adapter_18);
+    imports.wbg.__wbindgen_closure_wrapper87 = function(arg0, arg1, arg2) {
+        const ret = makeMutClosure(arg0, arg1, 31, __wbg_adapter_18);
         return addHeapObject(ret);
     };
     imports.wbg.__wbindgen_debug_string = function(arg0, arg1) {

src/pkg/lightningbeam_core_bg.wasm.d.ts

@@ -9,6 +9,7 @@ export const coreinterface_new: () => number;
 export const coreinterface_init: (a: number) => void;
 export const coreinterface_play: (a: number, b: number) => void;
 export const coreinterface_stop: (a: number) => void;
+export const coreinterface_resume_audio: (a: number, b: number) => void;
 export const coreinterface_add_sine_track: (a: number, b: number, c: number) => void;
 export const coreinterface_get_timestamp: (a: number) => number;
 export const coreinterface_get_tracks: (a: number, b: number) => void;