Add WIP sound generation

src/audio/noise-burst-player.ts

@@ -0,0 +1,49 @@
+import { GardenAudioGraph } from './garden-audio-graph';
+import { NoiseBurst } from './garden-audio-types';
+
+export class NoiseBurstPlayer {
+  public constructor(private readonly graph: GardenAudioGraph) {}
+
+  public play({ startTime, durationSeconds, gain, filterHz, pan }: NoiseBurst): void {
+    const { context, eventBus, noiseBuffer } = this.graph;
+    if (!context || !eventBus || !noiseBuffer) {
+      return;
+    }
+
+    const scheduledStart = Math.max(context.currentTime + 0.002, startTime);
+    const source = context.createBufferSource();
+    const filter = context.createBiquadFilter();
+    const envelope = context.createGain();
+    const panner = context.createStereoPanner();
+    const stopAt = scheduledStart + durationSeconds;
+
+    source.buffer = noiseBuffer;
+    filter.type = 'bandpass';
+    filter.frequency.setValueAtTime(filterHz, scheduledStart);
+    filter.Q.value = 1.4;
+    envelope.gain.setValueAtTime(0.0001, scheduledStart);
+    envelope.gain.exponentialRampToValueAtTime(
+      Math.max(0.0001, gain),
+      scheduledStart + 0.004
+    );
+    envelope.gain.exponentialRampToValueAtTime(0.0001, stopAt);
+    panner.pan.setValueAtTime(pan, scheduledStart);
+
+    source.connect(filter);
+    filter.connect(envelope);
+    envelope.connect(panner);
+    panner.connect(eventBus);
+    source.start(scheduledStart, Math.random() * 0.4);
+    source.stop(stopAt);
+    source.addEventListener(
+      'ended',
+      () => {
+        source.disconnect();
+        filter.disconnect();
+        envelope.disconnect();
+        panner.disconnect();
+      },
+      { once: true }
+    );
+  }
+}