feat: integrate authored nightdrive soundtrack

src/composables/useAudioEngine.ts

@@ -1,4 +1,5 @@
 import {
+  computed,
   onMounted,
   onUnmounted,
   readonly,
@@ -7,14 +8,17 @@ import {
   type Ref,
 } from 'vue';
 import { createAudioController } from '@/audio/create-audio-controller';
-import { createBrowserSynthEngine } from '@/audio/synth-engine';
-import type { AudioController, AudioUiState } from '@/audio/types';
+import { createBrowserSoundtrackEngine } from '@/audio/soundtrack-engine';
+import { resolveJourneyMusicState } from '@/audio/journey-music-state';
+import type { AudioController, AudioUiState, SoundtrackSources } from '@/audio/types';
 
 declare const __PORTFOLIO_TEST_BUILD__: boolean;
 const TEST_BUILD = typeof __PORTFOLIO_TEST_BUILD__ !== 'undefined' && __PORTFOLIO_TEST_BUILD__;
 
 export interface AudioEngineSources {
+  activeSectionId: Readonly<Ref<string>>;
   intensity: Readonly<Ref<number>>;
+  soundtrack: Readonly<Ref<SoundtrackSources | null>>;
   volume: Readonly<Ref<number>>;
   setVolume(value: number): void;
 }
@@ -34,20 +38,28 @@ export function useAudioEngine(sources: AudioEngineSources): AudioEngineBinding
   let controller: AudioController | null = null;
   let removeSubscription = (): void => {};
   let removePageListeners = (): void => {};
+  const journeyState = computed(() => resolveJourneyMusicState(
+    sources.activeSectionId.value,
+    sources.intensity.value,
+  ));
 
   const ensureController = (): AudioController => {
     if (controller) return controller;
     controller = createAudioController({
-      createGraph: createBrowserSynthEngine,
+      createGraph: (initialState) => {
+        const soundtrack = sources.soundtrack.value;
+        if (soundtrack === null) throw new Error('Soundtrack assets are unavailable.');
+        return createBrowserSoundtrackEngine(soundtrack, initialState);
+      },
       initialVolume: sources.volume.value,
       initiallyVisible: document.visibilityState !== 'hidden',
+      initialJourneyState: journeyState.value,
     });
     removeSubscription = controller.subscribe((next) => { state.value = next; });
-    controller.setIntensity(sources.intensity.value);
     return controller;
   };
 
-  watch(sources.intensity, (value) => controller?.setIntensity(value));
+  watch(journeyState, (state) => controller?.setJourneyState(state), { flush: 'sync' });
   watch(sources.volume, (value) => controller?.setVolume(value));
 
   onMounted(() => {