feat: add afterglow and synchronized drive lift

This commit is contained in:
2026-09-04 16:12:14 +03:00
parent 4c7d46ba0e
commit 5172b5bc4b
3 changed files with 804 additions and 173 deletions

View File

@@ -1,4 +1,8 @@
import {
AFTERGLOW_LOOP_END_SECONDS,
AFTERGLOW_LOOP_START_SECONDS,
AFTERGLOW_TRANSITION_SECONDS,
DRIVE_LIFT_LOOP_SECONDS,
INTRO_FIRST_PASS_END_SECONDS,
INTRO_IN_END_SECONDS,
INTRO_LOOP_END_SECONDS,
@@ -9,166 +13,343 @@ import {
SOUNDTRACK_SAMPLE_RATE,
mainPhraseOffsetSeconds,
nextSafeBarTime,
phaseAlignedLoopOffset,
resolveMainSchedule,
type MainSchedule,
} from '@/audio/soundtrack-transport';
import {
createAdaptiveMixer,
type AdaptiveMixerFactory,
} from '@/audio/adaptive-mixer';
import {
createDriveTexture,
type DriveTexture,
type DriveTextureFactory,
} from '@/audio/drive-texture';
import { isTestFault, recordTestFaultEvent } from '@/testing/fault-hooks';
import type {
AudioContextLifecycleState,
AudioGraph,
AudioInitialState,
ChapterIntent,
DriveEnergySample,
MusicMood,
AudioSourceVariant,
SoundtrackSources,
} from '@/audio/types';
declare const __PORTFOLIO_TEST_BUILD__: boolean;
const TEST_BUILD = typeof __PORTFOLIO_TEST_BUILD__ !== 'undefined' && __PORTFOLIO_TEST_BUILD__;
const SOURCE_LEAD_SECONDS = 0.08;
const START_FADE_SECONDS = 0.8;
const EXIT_CROSSFADE_SECONDS = 0.25;
const EXIT_MINIMUM_LEAD_SECONDS = 0.35;
const EXIT_COALESCE_MS = 120;
const PROFILE_RAMP_SECONDS = 0.85;
interface SourceHandle {
interface OwnedSource {
readonly node: AudioBufferSourceNode;
stopAt(when: number): void;
cancel(): void;
}
interface SourceHandle extends OwnedSource {
readonly gain: GainNode;
}
interface MixProfile {
readonly gain: number;
readonly highShelfDb: number;
interface PendingIntroExit {
readonly requestedGeneration: number;
readonly transitionTime: number;
readonly outro: SourceHandle;
readonly main: SourceHandle;
readonly commitMarker: OwnedSource;
readonly mainStartMarker: OwnedSource;
readonly schedule: MainSchedule;
}
const MIX_PROFILES: Readonly<Record<MusicMood, MixProfile>> = Object.freeze({
open: { gain: 0.985, highShelfDb: -0.35 },
shadow: { gain: 0.97, highShelfDb: -0.9 },
lift: { gain: 1, highShelfDb: 0.35 },
resolve: { gain: 0.985, highShelfDb: -0.15 },
});
export interface SoundtrackEngineDependencies {
createContext(): AudioContext;
loadBuffer(
context: BaseAudioContext,
variants: readonly AudioSourceVariant[],
signal: AbortSignal,
): Promise<AudioBuffer>;
createMixer: AdaptiveMixerFactory;
createDriveTexture: DriveTextureFactory;
}
export function createBrowserSoundtrackEngine(
export function createSoundtrackEngine(
sources: SoundtrackSources,
initialState: AudioInitialState,
dependencies: SoundtrackEngineDependencies,
): AudioGraph {
const BrowserAudioContext = window.AudioContext;
if (BrowserAudioContext === undefined) throw new Error('Web Audio is unavailable.');
const context = new BrowserAudioContext({
latencyHint: 'playback',
sampleRate: SOUNDTRACK_SAMPLE_RATE,
});
const profileGain = context.createGain();
const tone = context.createBiquadFilter();
const context = dependencies.createContext();
const outputGain = context.createGain();
const sourceNodes = new Set<AudioBufferSourceNode>();
outputGain.gain.value = 0;
const mixer = dependencies.createMixer(context, outputGain);
let driveTexture: DriveTexture | null = null;
try {
driveTexture = dependencies.createDriveTexture(context, mixer.driveTextureInput);
} catch {
driveTexture = null;
}
const ownedSources = new Set<OwnedSource>();
const stateListeners = new Set<(state: AudioContextLifecycleState) => void>();
const loadController = new AbortController();
const activatedFromStart = initialState.chapter.atStart;
let latestChapter = initialState.chapter;
let latestDrive = initialState.drive;
let connected = false;
let closed = false;
const activatedFromStart = initialState.chapter.atStart;
let transportStarted = false;
let introStarted = false;
let mainCommitted = false;
let introAnchorTime = 0;
let introProgramGain: GainNode | null = null;
let introSourceNodes: AudioBufferSourceNode[] = [];
let introSourceNodes: SourceHandle[] = [];
let loadedIntroBuffer: AudioBuffer | null = null;
let loadedMainBuffer: AudioBuffer | null = null;
let mainBufferPromise: Promise<AudioBuffer> | null = null;
let loadController: AbortController | null = null;
let driveLiftBufferPromise: Promise<AudioBuffer | null> | null = null;
let afterglowBufferPromise: Promise<AudioBuffer | null> | null = null;
let loadPromise: Promise<void> | null = null;
let exitTimer: number | undefined;
let exitLoadRequest: Promise<void> | null = null;
let pendingIntroExit: PendingIntroExit | null = null;
let driveScheduleAttached = false;
let afterglowScheduleAttached = false;
let driveLiftSource: SourceHandle | null = null;
let afterglowSource: SourceHandle | null = null;
let mainSource: SourceHandle | null = null;
let mainSchedule: MainSchedule | null = null;
tone.type = 'highshelf';
tone.frequency.value = 5_200;
tone.Q.value = 0.55;
outputGain.gain.value = 0;
profileGain.connect(tone);
tone.connect(outputGain);
const trackSource = (node: AudioBufferSourceNode): void => {
sourceNodes.add(node);
node.addEventListener('ended', () => {
sourceNodes.delete(node);
const ownSource = (
node: AudioBufferSourceNode,
releaseDependents: () => void,
): OwnedSource => {
let released = false;
let stopCalled = false;
let owned: OwnedSource;
const release = (): void => {
if (released) return;
released = true;
ownedSources.delete(owned);
node.disconnect();
}, { once: true });
releaseDependents();
};
const stopOnce = (when?: number): void => {
if (stopCalled) return;
stopCalled = true;
try {
if (when === undefined) node.stop();
else node.stop(when);
} catch {
// All teardown paths converge on the same idempotent release below.
}
};
owned = {
node,
stopAt(when) {
stopOnce(when);
},
cancel() {
stopOnce();
release();
},
};
ownedSources.add(owned);
node.addEventListener('ended', release, { once: true });
return owned;
};
const makeSource = (buffer: AudioBuffer): SourceHandle => {
const makeSource = (
buffer: AudioBuffer,
destination: AudioNode,
onRelease: () => void = () => {},
): SourceHandle => {
const node = context.createBufferSource();
const gain = context.createGain();
node.buffer = buffer;
node.connect(gain);
gain.connect(profileGain);
node.addEventListener('ended', () => gain.disconnect(), { once: true });
trackSource(node);
return { node, gain };
gain.connect(destination);
const owned = ownSource(node, () => {
gain.disconnect();
onRelease();
});
return { ...owned, gain };
};
const ramp = (parameter: AudioParam, value: number, duration: number): void => {
const now = context.currentTime;
holdParameter(parameter, now);
parameter.linearRampToValueAtTime(value, now + duration);
const makeMarker = (when: number, onEnded: () => void): OwnedSource => {
const node = context.createBufferSource();
node.buffer = context.createBuffer(1, 1, context.sampleRate);
const marker = ownSource(node, () => {});
node.addEventListener('ended', onEnded, { once: true });
node.start(when);
return marker;
};
const applyMix = (chapter: ChapterIntent): void => {
const profile = MIX_PROFILES[chapter.mood];
ramp(profileGain.gain, profile.gain, PROFILE_RAMP_SECONDS);
ramp(tone.gain, profile.highShelfDb, PROFILE_RAMP_SECONDS);
const loadOptional = (
variants: readonly AudioSourceVariant[],
): Promise<AudioBuffer | null> => dependencies
.loadBuffer(context, variants, loadController.signal)
.catch(() => null);
const ensureMainLoad = (): Promise<AudioBuffer> => {
if (mainBufferPromise !== null) return mainBufferPromise;
const promise = dependencies.loadBuffer(context, sources.main, loadController.signal);
mainBufferPromise = promise;
void promise.then((buffer) => {
if (!closed && !loadController.signal.aborted) loadedMainBuffer = buffer;
}).catch(() => undefined);
return promise;
};
const startMain = (
buffer: AudioBuffer,
when: number,
offsetSeconds: number,
fadeSeconds: number,
): SourceHandle => {
const main = makeSource(buffer);
const offset = Math.min(Math.max(0, offsetSeconds), Math.max(0, buffer.duration - 0.05));
const ensureDriveLiftLoad = (): Promise<AudioBuffer | null> => {
driveLiftBufferPromise ??= loadOptional(sources.driveLift);
return driveLiftBufferPromise;
};
const attachMainEnded = (main: SourceHandle): void => {
main.node.addEventListener('ended', () => {
if (mainSource !== main) return;
mainSource = null;
loadedMainBuffer = null;
mainBufferPromise = null;
}, { once: true });
};
const startDriveLift = (buffer: AudioBuffer, schedule: MainSchedule): void => {
if (closed || driveLiftSource !== null) return;
const when = Math.max(
schedule.sourceStartTime,
context.currentTime + SOURCE_LEAD_SECONDS,
);
const source = makeSource(buffer, mixer.driveLiftInput);
source.node.loop = true;
source.node.loopStart = 0;
source.node.loopEnd = DRIVE_LIFT_LOOP_SECONDS;
source.node.start(
when,
phaseAlignedLoopOffset(
when,
schedule.musicalAnchorTime,
DRIVE_LIFT_LOOP_SECONDS,
),
);
driveLiftSource = source;
mixer.setDriveLiftAvailableAt(when);
};
const startAfterglow = (buffer: AudioBuffer, schedule: MainSchedule): void => {
if (
closed
|| afterglowSource !== null
|| context.currentTime >= schedule.sourceEndTime
) return;
const when = Math.max(
schedule.afterglowStartTime,
context.currentTime + SOURCE_LEAD_SECONDS,
);
if (when >= schedule.sourceEndTime) return;
const offset = Math.max(0, when - schedule.afterglowStartTime);
if (offset >= AFTERGLOW_LOOP_END_SECONDS) return;
const source = makeSource(buffer, mixer.bedInput);
source.node.loop = true;
source.node.loopStart = AFTERGLOW_LOOP_START_SECONDS;
source.node.loopEnd = AFTERGLOW_LOOP_END_SECONDS;
const progress = Math.min(1, offset / AFTERGLOW_TRANSITION_SECONDS);
source.gain.gain.setValueAtTime(progress, when);
source.gain.gain.linearRampToValueAtTime(1, schedule.sourceEndTime);
source.node.start(when, offset);
afterglowSource = source;
};
const beginDriveLayer = (schedule: MainSchedule): void => {
if (closed || driveScheduleAttached) return;
driveScheduleAttached = true;
const promise = ensureDriveLiftLoad();
void promise.then((buffer) => {
driveLiftBufferPromise = null;
if (buffer !== null) startDriveLift(buffer, schedule);
});
};
const beginAfterglowLayer = (schedule: MainSchedule): void => {
if (closed || afterglowScheduleAttached) return;
afterglowScheduleAttached = true;
const promise = loadOptional(sources.afterglow);
afterglowBufferPromise = promise;
void promise.then((buffer) => {
afterglowBufferPromise = null;
if (buffer !== null) startAfterglow(buffer, schedule);
});
};
const startDirectMain = (buffer: AudioBuffer): void => {
const when = context.currentTime + SOURCE_LEAD_SECONDS;
const schedule = resolveMainSchedule({
startTime: when,
offsetSeconds: mainPhraseOffsetSeconds(latestChapter.entryPhrase),
bufferDuration: buffer.duration,
});
const main = makeSource(buffer, mixer.bedInput);
main.gain.gain.setValueAtTime(0, when);
main.gain.gain.linearRampToValueAtTime(1, when + fadeSeconds);
main.node.start(when, offset);
main.gain.gain.linearRampToValueAtTime(1, when + START_FADE_SECONDS);
main.node.start(when, schedule.sourceOffsetSeconds);
mainCommitted = true;
return main;
mainSource = main;
mainSchedule = schedule;
attachMainEnded(main);
mixer.setTransportAnchor(schedule.musicalAnchorTime);
beginDriveLayer(schedule);
beginAfterglowLayer(schedule);
};
const startIntro = (buffer: AudioBuffer, when: number): void => {
const lead = context.createBufferSource();
const loop = context.createBufferSource();
const programGain = context.createGain();
lead.buffer = buffer;
loop.buffer = buffer;
loop.loop = true;
loop.loopStart = INTRO_LOOP_START_SECONDS;
loop.loopEnd = INTRO_LOOP_END_SECONDS;
lead.connect(programGain);
loop.connect(programGain);
programGain.connect(profileGain);
programGain.connect(mixer.bedInput);
programGain.gain.setValueAtTime(0, when);
programGain.gain.linearRampToValueAtTime(1, when + START_FADE_SECONDS);
trackSource(lead);
trackSource(loop);
lead.start(when, 0, INTRO_FIRST_PASS_END_SECONDS);
loop.start(when + INTRO_FIRST_PASS_END_SECONDS, INTRO_LOOP_START_SECONDS);
let remainingSources = 2;
let programReleased = false;
const releaseProgram = (): void => {
remainingSources -= 1;
if (remainingSources !== 0 || programReleased) return;
programReleased = true;
programGain.disconnect();
if (introProgramGain === programGain) introProgramGain = null;
};
const lead = makeSource(buffer, programGain, releaseProgram);
const loop = makeSource(buffer, programGain, releaseProgram);
loop.node.loop = true;
loop.node.loopStart = INTRO_LOOP_START_SECONDS;
loop.node.loopEnd = INTRO_LOOP_END_SECONDS;
lead.node.start(when, 0, INTRO_FIRST_PASS_END_SECONDS);
loop.node.start(when + INTRO_FIRST_PASS_END_SECONDS, INTRO_LOOP_START_SECONDS);
introProgramGain = programGain;
introSourceNodes = [lead, loop];
introAnchorTime = when;
introStarted = true;
};
const scheduleIntroExit = (introBuffer: AudioBuffer, mainBuffer: AudioBuffer): void => {
if (!introStarted || mainCommitted || introProgramGain === null || closed) return;
mainCommitted = true;
const schedulingTime = Math.max(
const scheduleIntroExit = (
introBuffer: AudioBuffer,
mainBuffer: AudioBuffer,
requestedGeneration: number,
): void => {
if (
closed
|| !introStarted
|| mainCommitted
|| pendingIntroExit !== null
|| latestChapter.atStart
|| introProgramGain === null
) return;
const transitionTime = nextSafeBarTime(
Math.max(
context.currentTime,
introAnchorTime + INTRO_IN_END_SECONDS - EXIT_MINIMUM_LEAD_SECONDS,
);
const transitionTime = nextSafeBarTime(
schedulingTime,
),
introAnchorTime,
EXIT_MINIMUM_LEAD_SECONDS,
);
const outro = makeSource(introBuffer);
const outro = makeSource(introBuffer, mixer.bedInput);
outro.gain.gain.setValueAtTime(0, transitionTime);
outro.gain.gain.linearRampToValueAtTime(1, transitionTime + EXIT_CROSSFADE_SECONDS);
outro.node.start(
@@ -179,34 +360,103 @@ export function createBrowserSoundtrackEngine(
introProgramGain.gain.cancelScheduledValues(transitionTime);
introProgramGain.gain.setValueAtTime(1, transitionTime);
introProgramGain.gain.linearRampToValueAtTime(0, transitionTime + EXIT_CROSSFADE_SECONDS);
for (const source of introSourceNodes) {
stopSourceAt(source, transitionTime + EXIT_CROSSFADE_SECONDS);
}
introProgramGain.gain.linearRampToValueAtTime(
0,
transitionTime + EXIT_CROSSFADE_SECONDS,
);
const mainTime = transitionTime + INTRO_OUT_END_SECONDS - INTRO_OUT_START_SECONDS;
const main = startMain(mainBuffer, mainTime, 0, EXIT_CROSSFADE_SECONDS);
const schedule = resolveMainSchedule({
startTime: mainTime,
offsetSeconds: 0,
bufferDuration: mainBuffer.duration,
});
const main = makeSource(mainBuffer, mixer.bedInput);
main.gain.gain.setValueAtTime(0, mainTime);
main.gain.gain.linearRampToValueAtTime(1, mainTime + EXIT_CROSSFADE_SECONDS);
main.node.start(mainTime, 0);
outro.gain.gain.cancelScheduledValues(mainTime);
outro.gain.gain.setValueAtTime(1, mainTime);
outro.gain.gain.linearRampToValueAtTime(0, mainTime + EXIT_CROSSFADE_SECONDS);
const finishedProgramGain = introProgramGain;
outro.node.addEventListener('ended', () => {
finishedProgramGain.disconnect();
if (introProgramGain === finishedProgramGain) introProgramGain = null;
introSourceNodes = [];
let pending!: PendingIntroExit;
const commitMarker = makeMarker(transitionTime, () => {
if (closed || pendingIntroExit !== pending) return;
mainCommitted = true;
pendingIntroExit = null;
mainSource = main;
mainSchedule = schedule;
attachMainEnded(main);
for (const source of introSourceNodes) {
source.stopAt(transitionTime + EXIT_CROSSFADE_SECONDS);
}
loadedIntroBuffer = null;
introStarted = false;
}, { once: true });
beginDriveLayer(schedule);
});
const mainStartMarker = makeMarker(mainTime, () => {
if (closed || mainSchedule !== schedule) return;
mixer.setTransportAnchor(schedule.musicalAnchorTime);
beginAfterglowLayer(schedule);
});
pending = {
requestedGeneration,
transitionTime,
outro,
main,
commitMarker,
mainStartMarker,
schedule,
};
pendingIntroExit = pending;
};
const cancelPendingIntroExit = (): void => {
const pending = pendingIntroExit;
if (pending === null || context.currentTime >= pending.transitionTime) return;
pendingIntroExit = null;
pending.outro.cancel();
pending.main.cancel();
pending.commitMarker.cancel();
pending.mainStartMarker.cancel();
if (introProgramGain !== null) {
holdParameter(introProgramGain.gain, context.currentTime);
introProgramGain.gain.linearRampToValueAtTime(1, context.currentTime + 0.05);
}
};
const requestIntroExit = (requestedGeneration: number): void => {
if (
closed
|| !introStarted
|| mainCommitted
|| pendingIntroExit !== null
|| exitLoadRequest !== null
) return;
const introBuffer = loadedIntroBuffer;
const mainPromise = mainBufferPromise;
if (introBuffer === null || mainPromise === null) return;
if (loadedMainBuffer !== null) {
scheduleIntroExit(introBuffer, loadedMainBuffer, requestedGeneration);
return;
}
exitLoadRequest = mainPromise.then((mainBuffer) => {
if (!closed && !latestChapter.atStart && !mainCommitted) {
scheduleIntroExit(introBuffer, mainBuffer, requestedGeneration);
}
}).catch(() => undefined).finally(() => {
exitLoadRequest = null;
});
};
const loadAndStart = async (): Promise<void> => {
loadController = new AbortController();
ensureDriveLiftLoad();
const signal = loadController.signal;
mainBufferPromise = loadAudioBuffer(context, sources.main, signal);
void mainBufferPromise.catch(() => undefined);
const mainPromise = ensureMainLoad();
void mainPromise.catch(() => undefined);
if (activatedFromStart) {
loadedIntroBuffer = await loadAudioBuffer(context, sources.intro, signal);
loadedIntroBuffer = await dependencies.loadBuffer(context, sources.intro, signal);
if (closed || signal.aborted) throw abortError();
if (latestChapter.atStart) {
transportStarted = true;
@@ -215,7 +465,7 @@ export function createBrowserSoundtrackEngine(
}
}
const mainBuffer = await mainBufferPromise;
const mainBuffer = await mainPromise;
if (closed || signal.aborted) throw abortError();
if (activatedFromStart && latestChapter.atStart && loadedIntroBuffer !== null) {
transportStarted = true;
@@ -223,34 +473,13 @@ export function createBrowserSoundtrackEngine(
return;
}
transportStarted = true;
startMain(
mainBuffer,
context.currentTime + SOURCE_LEAD_SECONDS,
mainPhraseOffsetSeconds(latestChapter.entryPhrase),
START_FADE_SECONDS,
);
startDirectMain(mainBuffer);
};
const requestIntroExit = (): void => {
if (!introStarted || mainCommitted || exitTimer !== undefined || closed) return;
exitTimer = window.setTimeout(() => {
exitTimer = undefined;
if (closed || latestChapter.atStart || mainCommitted) return;
const introBuffer = loadedIntroBuffer;
const pendingMain = mainBufferPromise;
if (introBuffer === null || pendingMain === null) return;
void pendingMain.then((mainBuffer) => {
if (!closed && !latestChapter.atStart && !mainCommitted) {
scheduleIntroExit(introBuffer, mainBuffer);
}
}).catch(() => undefined);
}, EXIT_COALESCE_MS);
};
const cancelUnscheduledIntroExit = (): void => {
if (exitTimer === undefined) return;
window.clearTimeout(exitTimer);
exitTimer = undefined;
const rampOutput = (value: number): void => {
const now = context.currentTime;
holdParameter(outputGain.gain, now);
outputGain.gain.linearRampToValueAtTime(value, now + 0.08);
};
const onStateChange = (): void => {
@@ -258,12 +487,15 @@ export function createBrowserSoundtrackEngine(
for (const listener of stateListeners) listener(state);
};
context.addEventListener('statechange', onStateChange);
applyMix(initialState.chapter);
mixer.setChapterIntent(latestChapter);
mixer.setDriveEnergy(latestDrive);
driveTexture?.setEnergy(latestDrive);
return {
async resume() {
if (closed) throw new DOMException('Audio graph is closed.', 'InvalidStateError');
await context.resume();
ensureDriveLiftLoad();
if (transportStarted) return;
loadPromise ??= loadAndStart();
await loadPromise;
@@ -274,15 +506,22 @@ export function createBrowserSoundtrackEngine(
async close() {
if (closed) return;
closed = true;
if (exitTimer !== undefined) window.clearTimeout(exitTimer);
loadController?.abort();
for (const source of sourceNodes) stopSource(source);
sourceNodes.clear();
loadController.abort();
cancelPendingIntroExit();
mixer.setDriveLiftAvailableAt(null);
driveTexture?.dispose();
driveTexture = null;
mixer.dispose();
for (const source of [...ownedSources]) source.cancel();
ownedSources.clear();
context.removeEventListener('statechange', onStateChange);
stateListeners.clear();
profileGain.disconnect();
tone.disconnect();
outputGain.disconnect();
connected = false;
loadedIntroBuffer = null;
loadedMainBuffer = null;
afterglowBufferPromise = null;
driveLiftBufferPromise = null;
if (context.state !== 'closed') await context.close();
},
connectOutput() {
@@ -296,24 +535,26 @@ export function createBrowserSoundtrackEngine(
connected = false;
},
setOutputGain(value) {
ramp(outputGain.gain, clamp(value), 0.08);
if (!closed) rampOutput(clamp(value));
},
setChapterIntent(intent) {
if (closed) return;
latestChapter = intent;
applyMix(intent);
if (!intent.atStart) requestIntroExit();
else cancelUnscheduledIntroExit();
mixer.setChapterIntent(intent);
if (!mainCommitted && introStarted) {
if (intent.atStart) cancelPendingIntroExit();
else requestIntroExit(intent.generation);
}
},
setDriveEnergy(_sample: DriveEnergySample) {
setDriveEnergy(sample) {
if (closed) return;
latestDrive = sample;
driveTexture?.setEnergy(sample);
mixer.setDriveEnergy(sample);
},
cancelPending() {
loadController?.abort();
if (exitTimer !== undefined) {
window.clearTimeout(exitTimer);
exitTimer = undefined;
}
loadController.abort();
cancelPendingIntroExit();
},
onContextStateChange(listener) {
stateListeners.add(listener);
@@ -322,9 +563,56 @@ export function createBrowserSoundtrackEngine(
};
}
export function createBrowserSoundtrackEngine(
sources: SoundtrackSources,
initialState: AudioInitialState,
): AudioGraph {
if (TEST_BUILD && isTestFault('F10-audio-start-rejection')) {
recordTestFaultEvent('audio-start-rejected');
throw new DOMException('Injected audio start rejection', 'NotAllowedError');
}
const BrowserAudioContext = window.AudioContext
?? (window as typeof window & {
webkitAudioContext?: typeof AudioContext;
}).webkitAudioContext;
if (BrowserAudioContext === undefined) throw new Error('Web Audio is unavailable.');
const graph = createSoundtrackEngine(sources, initialState, {
createContext: () => new BrowserAudioContext({
latencyHint: 'playback',
sampleRate: SOUNDTRACK_SAMPLE_RATE,
}),
loadBuffer: loadAudioBuffer,
createMixer: createAdaptiveMixer,
createDriveTexture,
});
let resumeCount = 0;
return {
...graph,
async resume() {
resumeCount += 1;
if (isTestFault('F11-audio-resume-rejection') && resumeCount > 1) {
recordTestFaultEvent('audio-resume-rejected');
throw new DOMException('Injected audio resume rejection', 'NotAllowedError');
}
if (isTestFault('F12-audio-graph-invalid') && resumeCount > 1) {
recordTestFaultEvent('audio-graph-invalid');
throw new DOMException('Injected invalid audio graph', 'InvalidStateError');
}
await graph.resume();
},
async suspend() {
if (isTestFault('F13-audio-suspend-rejection')) {
recordTestFaultEvent('audio-suspend-rejected');
throw new DOMException('Injected audio suspend rejection', 'InvalidStateError');
}
await graph.suspend();
},
};
}
async function loadAudioBuffer(
context: BaseAudioContext,
variants: readonly SoundtrackSources['intro'][number][],
variants: readonly AudioSourceVariant[],
signal: AbortSignal,
): Promise<AudioBuffer> {
const ordered = orderSupportedVariants(variants);
@@ -332,7 +620,10 @@ async function loadAudioBuffer(
for (const variant of ordered) {
if (signal.aborted) throw abortError();
try {
const response = await fetch(variant.url, { signal, credentials: 'same-origin' });
const response = await fetch(variant.url, {
signal,
credentials: 'same-origin',
});
if (!response.ok) throw new Error(`Soundtrack request failed (${response.status}).`);
const encoded = await response.arrayBuffer();
if (signal.aborted) throw abortError();
@@ -342,15 +633,18 @@ async function loadAudioBuffer(
lastError = error;
}
}
throw lastError instanceof Error ? lastError : new Error('No supported soundtrack source loaded.');
throw lastError instanceof Error
? lastError
: new Error('No supported soundtrack source loaded.');
}
function orderSupportedVariants<T extends SoundtrackSources['intro'][number]>(
function orderSupportedVariants<T extends AudioSourceVariant>(
variants: readonly T[],
): readonly T[] {
const probe = document.createElement('audio');
return [...variants].sort((left, right) => (
Number(probe.canPlayType(right.mediaType) !== '') - Number(probe.canPlayType(left.mediaType) !== '')
Number(probe.canPlayType(right.mediaType) !== '')
- Number(probe.canPlayType(left.mediaType) !== '')
));
}
@@ -363,23 +657,6 @@ function holdParameter(parameter: AudioParam, atTime: number): void {
parameter.setValueAtTime(parameter.value, atTime);
}
function stopSource(source: AudioBufferSourceNode): void {
try {
source.stop();
} catch {
// An already-ended or not-yet-started source is safe to ignore during teardown.
}
source.disconnect();
}
function stopSourceAt(source: AudioBufferSourceNode, when: number): void {
try {
source.stop(when);
} catch {
// A source that already ended needs no scheduled cleanup.
}
}
function abortError(): DOMException {
return new DOMException('Soundtrack loading was cancelled.', 'AbortError');
}

View File

@@ -27,6 +27,9 @@ export interface FakeAudioHarness {
readonly gainNodes: readonly GainNode[];
readonly buffers: AudioBuffer[];
readonly destination: AudioNode;
readonly resumeCount: number;
readonly suspendCount: number;
readonly closeCount: number;
setCurrentTime(seconds: number): void;
decodedBuffer(durationSeconds: number, channels?: number): AudioBuffer;
emitContextState(state: AudioContextState | 'interrupted'): void;
@@ -105,6 +108,9 @@ export function createFakeAudioHarness(): FakeAudioHarness {
const sampleRate = 48_000;
let currentTime = 0;
let state: AudioContextState | 'interrupted' = 'suspended';
let resumeCount = 0;
let suspendCount = 0;
let closeCount = 0;
const decodedBuffer = (durationSeconds: number, channels = 2): AudioBuffer => {
const length = Math.max(1, Math.round(durationSeconds * sampleRate));
@@ -232,12 +238,15 @@ export function createFakeAudioHarness(): FakeAudioHarness {
return decodedBuffer(1);
},
async resume() {
resumeCount += 1;
state = 'running';
},
async suspend() {
suspendCount += 1;
state = 'suspended';
},
async close() {
closeCount += 1;
state = 'closed';
},
addEventListener(type: string, listener: () => void) {
@@ -255,6 +264,15 @@ export function createFakeAudioHarness(): FakeAudioHarness {
gainNodes,
buffers,
destination,
get resumeCount() {
return resumeCount;
},
get suspendCount() {
return suspendCount;
},
get closeCount() {
return closeCount;
},
setCurrentTime(seconds) {
currentTime = seconds;
},

View File

@@ -0,0 +1,336 @@
import { describe, expect, it, vi } from 'vitest';
import { createSoundtrackEngine } from '@/audio/soundtrack-engine';
import { resolveChapterIntent } from '@/audio/journey-music-state';
import {
AFTERGLOW_LOOP_END_SECONDS,
AFTERGLOW_LOOP_START_SECONDS,
DRIVE_LIFT_LOOP_SECONDS,
INTRO_RUNTIME_END_SECONDS,
MAIN_DURATION_SECONDS,
mainPhraseOffsetSeconds,
phaseAlignedLoopOffset,
} from '@/audio/soundtrack-transport';
import type { AdaptiveMixer } from '@/audio/adaptive-mixer';
import type { DriveTexture } from '@/audio/drive-texture';
import type {
AudioInitialState,
SoundtrackSources,
} from '@/audio/types';
import {
createFakeAudioHarness,
type FakeAudioHarness,
type FakeSourceRecord,
} from '../helpers/fake-audio-context';
const sources: SoundtrackSources = {
intro: [{ url: '/intro.opus', mediaType: 'audio/ogg' }],
main: [{ url: '/main.opus', mediaType: 'audio/ogg' }],
afterglow: [{ url: '/afterglow.opus', mediaType: 'audio/ogg' }],
driveLift: [{ url: '/drive-lift.opus', mediaType: 'audio/ogg' }],
};
const initialState: AudioInitialState = {
chapter: resolveChapterIntent('start'),
drive: { energy: 0, source: 'idle' },
};
interface EngineHarnessOptions {
readonly rejectIntro?: boolean;
readonly rejectMain?: boolean;
readonly rejectAfterglow?: boolean;
readonly rejectDriveLift?: boolean;
readonly rejectDriveTexture?: boolean;
readonly deferDriveLift?: boolean;
}
interface Deferred<T> {
readonly promise: Promise<T>;
resolve(value: T): void;
}
function deferred<T>(): Deferred<T> {
let resolve!: (value: T) => void;
const promise = new Promise<T>((settle) => { resolve = settle; });
return { promise, resolve };
}
function createEngineHarness(
state: AudioInitialState = initialState,
options: EngineHarnessOptions = {},
) {
const harness = createFakeAudioHarness();
const buffers = new Map([
['/intro.opus', harness.decodedBuffer(INTRO_RUNTIME_END_SECONDS)],
['/main.opus', harness.decodedBuffer(MAIN_DURATION_SECONDS)],
['/afterglow.opus', harness.decodedBuffer(AFTERGLOW_LOOP_END_SECONDS)],
['/drive-lift.opus', harness.decodedBuffer(DRIVE_LIFT_LOOP_SECONDS)],
]);
const pendingDriveLift = deferred<AudioBuffer>();
const loadCalls: string[] = [];
const loadPromises: Promise<AudioBuffer>[] = [];
const bedInput = harness.context.createGain();
const driveLiftInput = harness.context.createGain();
const driveTextureInput = harness.context.createGain();
const mixer = {
bedInput,
driveLiftInput,
driveTextureInput,
setChapterIntent: vi.fn(),
setDriveEnergy: vi.fn(),
setTransportAnchor: vi.fn(),
setDriveLiftAvailableAt: vi.fn(),
dispose: vi.fn(),
} satisfies AdaptiveMixer;
const texture = {
setEnergy: vi.fn(),
dispose: vi.fn(),
} satisfies DriveTexture;
const createMixer = vi.fn(() => mixer);
const createDriveTexture = vi.fn(() => {
if (options.rejectDriveTexture) throw new Error('drive texture unavailable');
return texture;
});
const loadBuffer = vi.fn((
_context: BaseAudioContext,
variants: SoundtrackSources['intro'],
): Promise<AudioBuffer> => {
const url = variants[0]?.url;
if (url === undefined) return Promise.reject(new Error('missing source'));
loadCalls.push(url);
const reject = (
(url === '/intro.opus' && options.rejectIntro)
|| (url === '/main.opus' && options.rejectMain)
|| (url === '/afterglow.opus' && options.rejectAfterglow)
|| (url === '/drive-lift.opus' && options.rejectDriveLift)
);
const buffer = buffers.get(url);
let promise: Promise<AudioBuffer>;
if (reject || buffer === undefined) promise = Promise.reject(new Error(`${url} unavailable`));
else if (url === '/drive-lift.opus' && options.deferDriveLift) promise = pendingDriveLift.promise;
else promise = Promise.resolve(buffer);
loadPromises.push(promise);
return promise;
});
const graph = createSoundtrackEngine(sources, state, {
createContext: () => harness.context,
loadBuffer,
createMixer,
createDriveTexture,
});
const sourcesFor = (url: string): FakeSourceRecord[] => {
const buffer = buffers.get(url);
return harness.sources.filter((record) => (
(record.node as AudioBufferSourceNode).buffer === buffer
));
};
const sourceFor = (url: string): FakeSourceRecord => {
const record = sourcesFor(url).at(-1);
if (record === undefined) throw new Error(`Missing source for ${url}.`);
return record;
};
const markers = (): FakeSourceRecord[] => harness.sources.filter((record) => {
const buffer = (record.node as AudioBufferSourceNode).buffer;
return record.kind === 'buffer' && buffer !== null && ![...buffers.values()].includes(buffer);
});
const flushOptionalLoads = async (): Promise<void> => {
await Promise.allSettled([...loadPromises]);
await Promise.resolve();
await Promise.resolve();
};
return {
graph,
harness,
mixer,
texture,
loadCalls,
sourcesFor,
sourceFor,
markers,
flushOptionalLoads,
resolveDriveLift() {
const buffer = buffers.get('/drive-lift.opus');
if (buffer === undefined) throw new Error('Missing drive lift buffer.');
pendingDriveLift.resolve(buffer);
},
};
}
describe('soundtrack engine', () => {
it('cancels a Start departure before its audible bar boundary', async () => {
const test = createEngineHarness();
await test.graph.resume();
test.graph.setChapterIntent(resolveChapterIntent('profile', 1));
const pendingMain = test.sourcesFor('/main.opus').at(-1)!;
const pendingOutro = test.sourcesFor('/intro.opus').at(-1)!;
expect(pendingMain.starts).toHaveLength(1);
expect(pendingOutro.starts).toHaveLength(1);
test.graph.setChapterIntent(resolveChapterIntent('start', 2));
expect(pendingMain.stops).toHaveLength(1);
expect(pendingOutro.stops).toHaveLength(1);
expect(test.mixer.setTransportAnchor).not.toHaveBeenCalledWith(expect.any(Number));
});
it('reuses one pending Start departure across rapid non-Start moods', async () => {
const test = createEngineHarness();
await test.graph.resume();
test.graph.setChapterIntent(resolveChapterIntent('profile', 1));
const mainCount = test.sourcesFor('/main.opus').length;
const introCount = test.sourcesFor('/intro.opus').length;
test.graph.setChapterIntent(resolveChapterIntent('experience', 2));
test.graph.setChapterIntent(resolveChapterIntent('toolkit', 3));
expect(test.sourcesFor('/main.opus')).toHaveLength(mainCount);
expect(test.sourcesFor('/intro.opus')).toHaveLength(introCount);
expect(test.mixer.setChapterIntent).toHaveBeenLastCalledWith(
resolveChapterIntent('toolkit', 3),
);
});
it('keeps the main anchor unchanged across every mood command', async () => {
const test = createEngineHarness({
chapter: resolveChapterIntent('experience'),
drive: { energy: 0, source: 'idle' },
});
await test.graph.resume();
const main = test.sourceFor('/main.opus');
const firstAnchor = test.mixer.setTransportAnchor.mock.calls.find(
([anchor]) => typeof anchor === 'number',
)?.[0];
test.graph.setChapterIntent(resolveChapterIntent('contact', 1));
test.graph.setChapterIntent(resolveChapterIntent('start', 2));
expect(test.mixer.setTransportAnchor.mock.calls.filter(
([anchor]) => typeof anchor === 'number',
).map(([anchor]) => anchor)).toEqual([firstAnchor]);
expect(test.sourcesFor('/main.opus')).toEqual([main]);
expect(test.harness.params.find(
({ param }) => param === (main.node as AudioBufferSourceNode).playbackRate,
)?.events).toEqual([]);
});
it('loads afterglow only once the intro path main source has begun', async () => {
const test = createEngineHarness();
await test.graph.resume();
expect(test.loadCalls).toEqual(expect.arrayContaining(['/intro.opus', '/main.opus', '/drive-lift.opus']));
expect(test.loadCalls).not.toContain('/afterglow.opus');
test.graph.setChapterIntent(resolveChapterIntent('profile', 1));
const [commitMarker, mainStartMarker] = test.markers();
expect(commitMarker).toBeDefined();
expect(mainStartMarker).toBeDefined();
test.harness.setCurrentTime(commitMarker!.starts[0]!.at);
commitMarker!.emitEnded();
expect(test.loadCalls).not.toContain('/afterglow.opus');
const committedMain = test.sourceFor('/main.opus');
const committedOutro = test.sourcesFor('/intro.opus').at(-1)!;
test.graph.setChapterIntent(resolveChapterIntent('start', 2));
expect(committedMain.stops).toHaveLength(0);
expect(committedOutro.stops).toHaveLength(0);
test.harness.setCurrentTime(mainStartMarker!.starts[0]!.at);
mainStartMarker!.emitEnded();
expect(test.loadCalls.filter((url) => url === '/afterglow.opus')).toHaveLength(1);
});
it('starts one afterglow transition and loops only its eight-bar idle region', async () => {
const test = createEngineHarness({
chapter: resolveChapterIntent('toolkit'),
drive: { energy: 0, source: 'idle' },
});
await test.graph.resume();
await test.flushOptionalLoads();
const afterglow = test.sourceFor('/afterglow.opus');
expect(afterglow.starts).toHaveLength(1);
expect((afterglow.node as AudioBufferSourceNode).loop).toBe(true);
expect((afterglow.node as AudioBufferSourceNode).loopStart)
.toBe(AFTERGLOW_LOOP_START_SECONDS);
expect((afterglow.node as AudioBufferSourceNode).loopEnd)
.toBe(AFTERGLOW_LOOP_END_SECONDS);
});
it('contains optional failures and still resolves dominant playback', async () => {
const intro = createEngineHarness(initialState, {
rejectDriveLift: true,
rejectDriveTexture: true,
});
await expect(intro.graph.resume()).resolves.toBeUndefined();
await intro.flushOptionalLoads();
expect(intro.sourceFor('/intro.opus').starts).toHaveLength(1);
const direct = createEngineHarness({
chapter: resolveChapterIntent('profile'),
drive: { energy: 0, source: 'idle' },
}, { rejectAfterglow: true });
await expect(direct.graph.resume()).resolves.toBeUndefined();
await direct.flushOptionalLoads();
expect(direct.sourceFor('/main.opus').starts).toHaveLength(1);
expect(direct.sourcesFor('/afterglow.opus')).toHaveLength(0);
});
it('starts direct activation at the mapped phrase-seven source offset', async () => {
const test = createEngineHarness({
chapter: resolveChapterIntent('contact'),
drive: { energy: 0, source: 'idle' },
});
await test.graph.resume();
expect(test.sourceFor('/main.opus').starts[0]?.offset)
.toBe(mainPhraseOffsetSeconds(7));
});
it('phase-aligns a drive source that becomes ready after main starts', async () => {
const test = createEngineHarness({
chapter: resolveChapterIntent('experience'),
drive: { energy: 0.8, source: 'physical' },
}, { deferDriveLift: true });
await test.graph.resume();
const mainStart = test.sourceFor('/main.opus').starts[0]!;
const anchor = mainStart.at - mainStart.offset;
test.harness.setCurrentTime(13);
test.resolveDriveLift();
await test.flushOptionalLoads();
const drive = test.sourceFor('/drive-lift.opus');
expect(drive.starts).toHaveLength(1);
expect(drive.starts[0]!.offset).toBeCloseTo(
phaseAlignedLoopOffset(drive.starts[0]!.at, anchor, DRIVE_LIFT_LOOP_SECONDS),
8,
);
expect(test.mixer.setDriveLiftAvailableAt).toHaveBeenCalledWith(drive.starts[0]!.at);
});
it('routes drive commands immediately to texture and mixer', () => {
const test = createEngineHarness();
const sample = { energy: 0.72, source: 'physical' } as const;
test.graph.setDriveEnergy(sample);
expect(test.texture.setEnergy).toHaveBeenLastCalledWith(sample);
expect(test.mixer.setDriveEnergy).toHaveBeenLastCalledWith(sample);
});
it('keeps dominant intro and direct-main load failures terminal', async () => {
const intro = createEngineHarness(initialState, { rejectIntro: true });
await expect(intro.graph.resume()).rejects.toThrow('/intro.opus unavailable');
const main = createEngineHarness({
chapter: resolveChapterIntent('profile'),
drive: { energy: 0, source: 'idle' },
}, { rejectMain: true });
await expect(main.graph.resume()).rejects.toThrow('/main.opus unavailable');
});
it('stops and disconnects each owned source exactly once when closed twice', async () => {
const test = createEngineHarness();
await test.graph.resume();
test.graph.setChapterIntent(resolveChapterIntent('profile', 1));
expect(test.markers()).toHaveLength(2);
await test.graph.close();
await test.graph.close();
expect(test.harness.sources.length).toBeGreaterThan(0);
for (const source of test.harness.sources) {
expect(source.stops).toHaveLength(1);
expect(source.disconnectCount).toBe(1);
}
expect(test.texture.dispose).toHaveBeenCalledOnce();
expect(test.mixer.dispose).toHaveBeenCalledOnce();
expect(test.harness.closeCount).toBe(1);
});
});