[add] sound playback demo.

Author: vmarcella

demos/audio/src/bin/sound_playback_transport.rs

@@ -0,0 +1,52 @@
+#![allow(clippy::needless_return)]
+//! Audio demo exercising `AudioContext` transport controls.
+//!
+//! This demo validates that `AudioContext` can play a decoded `SoundBuffer`
+//! through the output device and that `SoundInstance` transport operations
+//! (play/pause/stop/looping) behave as expected.
+
+use std::time::Duration;
+
+use lambda::audio::{
+  AudioContextBuilder,
+  SoundBuffer,
+};
+
+fn main() {
+  const SLASH_VORBIS_STEREO_48000_OGG: &[u8] = include_bytes!(concat!(
+    env!("CARGO_MANIFEST_DIR"),
+    "/../../crates/lambda-rs-platform/assets/audio/slash_vorbis_stereo_48000.ogg"
+  ));
+
+  let buffer =
+    SoundBuffer::from_ogg_bytes(SLASH_VORBIS_STEREO_48000_OGG).unwrap();
+
+  let mut context = AudioContextBuilder::new()
+    .with_label("sound-playback-transport")
+    .with_sample_rate(buffer.sample_rate())
+    .with_channels(buffer.channels())
+    .build()
+    .unwrap();
+
+  let mut instance = context.play_sound(&buffer).unwrap();
+  std::thread::sleep(Duration::from_millis(250));
+
+  instance.pause();
+  std::thread::sleep(Duration::from_millis(250));
+
+  instance.play();
+  std::thread::sleep(Duration::from_millis(250));
+
+  instance.stop();
+  std::thread::sleep(Duration::from_millis(250));
+
+  instance.play();
+  std::thread::sleep(Duration::from_millis(300));
+
+  instance.set_looping(true);
+  std::thread::sleep(Duration::from_secs(2));
+
+  instance.set_looping(false);
+  std::thread::sleep(Duration::from_millis(300));
+  return;
+}