Files
ai.interactive.fiction/public/js/book-playback-timeline-module.js
Georg 705d1ea6bf Fix new-game title flip + cap lookahead prepare burst
Builds on the worker migration with prepare-burst pacing and a title-flip fix:

- New game from mid-game left the book on the previous game's spread, so the first block's
  source and target spread matched and the title->content page turn was skipped. story:client-reset
  now returns the book to the title spread (spread 0) so the first block flips 0->1 and animates.
  Verified: requiresSpreadTransition src=0 tgt=1, page-flip-started/near-end fire.

- The lookahead burst-prepared many blocks at once, spiking allocation/GC into multi-second
  main-thread stalls. WebGL book prepares are now serialized through a chain and capped to a
  small lookahead window (TTS audio prefetch still spans the full window); future lookahead is
  also deferred until the current sentence has entered the display pipeline, keeping it off the
  first flip/reveal critical path. Worst game-start stall ~6s -> ~3.4s.

- Page flips now drive the scene through the sceneControl prewarm/startPreparedPageFlip API
  (awaited) instead of an event, and the scene awaits the async initial spread draw.

Suite 177. Remaining: a per-block prepare stall (~1.6-3.4s for large blocks at game start)
that profiling has not yet attributed to a single function (likely GC from prepare-path
allocation) — needs a DevTools performance capture for exact attribution.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-20 00:59:01 +02:00

892 lines
41 KiB
JavaScript

/**
* Book Playback Timeline Module
*
* The single owner of WebGL book playback. It sequences the full content
* lifecycle for story text:
*
* prepare (pagination + textures + prewarm)
* -> commit (resolve the authoritative target spread)
* -> flip (animate a page turn when a spread boundary is crossed)
* -> activate (upload the visible textures for the target spread)
* -> reveal (animate the new block's text in)
*
* It drives the scene through the registered `webgl-book-scene` accessor and uses
* `webgl-book:*` events only as state notifications. It never touches
* `window.BookLabDebug` (debug-only). Cache and scene-preparation misses are
* surfaced as problem states instead of being hidden by alternate playback paths.
*/
import { BaseModule } from './base-module.js';
class BookPlaybackTimelineModule extends BaseModule {
constructor() {
super('book-playback-timeline', 'Book Playback Timeline');
this.dependencies = ['book-pagination', 'book-texture-renderer', 'webgl-page-cache', 'playback-coordinator', 'webgl-book-scene'];
this.pagination = null;
this.textureRenderer = null;
this.pageCache = null;
this.playbackCoordinator = null;
this.scene = null;
this.activeSegment = null;
this.preparedSegments = new Map();
this.maxPreparedSegments = 48;
this.paginationGeneration = 0;
this.visibleSpreadIndex = 0;
this.timelineDiagnostics = [];
this.benchmarkEntries = [];
this.bindMethods([
'initialize',
'playSentence',
'prepareSentence',
'commitSegmentSpread',
'activatePreparedSegment',
'ensureAnimationTimings',
'calculateAnimationTiming',
'createPreparedSegment',
'createRevealDetail',
'applyTexturePlan',
'startRevealForSegment',
'assertSegmentReady',
'collectRequiredPageMetas',
'collectTexturePlanPageMetas',
'requiresSpreadTransition',
'requiresRightPageFlipAfterReveal',
'getBlockRevealSides',
'waitForVisualCompletion',
'revealContinuationSpread',
'waitForPlannedRightReveal',
'requestPageFlip',
'prepareFlipPlan',
'waitForPageFlipFinished',
'prewarmSegmentTextures',
'getPageMetaForIndex',
'getVisibleSpreadIndex',
'isChoiceAwaitingPlayer',
'invalidatePreparedSegments',
'rememberPreparedSegment',
'markBenchmark',
'timeStage',
'recordDiagnostic',
'getRuntimeState'
]);
}
async initialize() {
this.pagination = this.getModule('book-pagination');
this.textureRenderer = this.getModule('book-texture-renderer');
this.pageCache = this.getModule('webgl-page-cache');
this.playbackCoordinator = this.getModule('playback-coordinator');
this.scene = this.getModule('webgl-book-scene');
this.visibleSpreadIndex = Math.max(0, Math.round(Number(this.pagination?.currentSpreadIndex || 0)));
this.addEventListener(document, 'webgl-book:page-reveal-start', (event) => {
this.markBenchmark('reveal-start', { blockId: event.detail?.blockId ?? null });
});
this.addEventListener(document, 'webgl-book:reveal-committed', (event) => {
this.markBenchmark('reveal-committed', {
blockId: event.detail?.blockIds?.[0] ?? null,
side: event.detail?.side || null,
pageFlipAfterReveal: event.detail?.pageFlipAfterReveal === true
});
});
this.addEventListener(document, 'webgl-book:page-flip-started', (event) => {
this.markBenchmark('flip-started', event.detail || {});
});
this.addEventListener(document, 'webgl-book:page-flip-finished', (event) => {
const targetSpread = Number(event.detail?.targetSpread);
if (Number.isFinite(targetSpread)) this.visibleSpreadIndex = Math.max(0, Math.round(targetSpread));
this.markBenchmark('flip-finished', event.detail || {});
});
this.addEventListener(document, 'webgl-book:page-count-changed', this.invalidatePreparedSegments);
this.addEventListener(document, 'story:history-restoring', this.invalidatePreparedSegments);
this.addEventListener(document, 'story:client-reset', () => {
this.invalidatePreparedSegments();
this.activeSegment = null;
});
window.BookPlaybackTimeline = this;
this.reportProgress(100, 'Book playback timeline ready');
return true;
}
async playSentence(sentence = {}) {
const segment = await this.timeStage('prepare-current', { blockId: sentence.blockId ?? null }, () => {
return this.prepareSentence(sentence, { immediate: true });
});
if (!segment) {
return this.playbackCoordinator?.play?.(sentence);
}
this.activeSegment = segment;
document.documentElement.dataset.webglBookPlaybackActive = 'true';
this.recordDiagnostic('segment-play:start', segment);
try {
segment.sourceSpreadIndex = this.getVisibleSpreadIndex();
// Commit pagination first so the flip targets the authoritative spread,
// not the predicted preview spread.
await this.timeStage('commit', segment, () => this.commitSegmentSpread(segment, sentence));
if (this.requiresSpreadTransition(segment)) {
const flipped = await this.timeStage('preplay-flip', segment, () => this.requestPageFlip(1, {
reason: 'timeline-preplay-spread-transition',
targetSpread: segment.targetSpreadIndex,
// The block reveals on these sides right after the flip; the scene must
// not flash their full (unmasked) content during the flip's near-end
// texture swap — activate will land the masked reveal instead.
revealSides: segment.revealSides,
force: true
}));
if (!flipped) {
this.pageCache?.recordProblem?.({
type: 'timeline-preplay-flip-failed',
blockId: segment.blockId,
targetSpread: segment.targetSpreadIndex
});
}
}
await this.timeStage('activate', segment, () => this.activatePreparedSegment(segment, sentence));
sentence.webglRevealController = () => this.startRevealForSegment(segment);
const playbackPromise = this.timeStage('playback', segment, () => {
return this.playbackCoordinator?.play?.(sentence) || Promise.resolve();
});
const visualPromise = this.waitForVisualCompletion(segment);
await Promise.all([playbackPromise, visualPromise]);
} finally {
this.recordDiagnostic('segment-play:end', segment);
if (this.activeSegment?.key === segment.key) this.activeSegment = null;
delete document.documentElement.dataset.webglBookPlaybackActive;
}
return segment;
}
async prepareSentence(sentence = {}, options = {}) {
if (!sentence || sentence.blockId == null || !this.pagination || !this.textureRenderer) return null;
const key = `${sentence.gameId || sentence.metadata?.gameId || 'game'}:${sentence.blockId}`;
const cached = sentence.webglBookPresentation?.timelineSegment || this.preparedSegments.get(key);
const reusable = cached && cached.generation === this.paginationGeneration;
if (reusable && options.force !== true) return cached;
this.ensureAnimationTimings(sentence);
const segment = await this.timeStage(options.immediate === true ? 'segment-prepare-immediate' : 'segment-prepare-lookahead', {
blockId: sentence.blockId,
id: sentence.id
}, () => this.createPreparedSegment(sentence, options));
if (!segment) return null;
this.rememberPreparedSegment(segment);
sentence.webglBookPresentation = {
...(sentence.webglBookPresentation || {}),
prepared: true,
blockId: segment.blockId,
spread: segment.previewSpread,
timelineSegment: segment
};
this.recordDiagnostic('segment-prepare:end', segment);
return segment;
}
rememberPreparedSegment(segment = {}) {
if (!segment?.key) return;
this.preparedSegments.delete(segment.key);
this.preparedSegments.set(segment.key, segment);
while (this.preparedSegments.size > this.maxPreparedSegments) {
const oldestKey = this.preparedSegments.keys().next().value;
this.preparedSegments.delete(oldestKey);
}
}
invalidatePreparedSegments() {
this.paginationGeneration += 1;
this.preparedSegments.clear();
}
async createPreparedSegment(sentence = {}, options = {}) {
const previewSpread = sentence.webglBookPresentation?.spread || await this.pagination.preparePendingBlock(sentence, {
activate: false,
publish: false,
includeUnrenderedHistory: true
});
if (!previewSpread) return null;
// Every block is prepared once, spanning-aware. The preview layout (attached to the
// preview spread by pagination) tells us whether the block overflows onto the next
// spread; if so we derive the start spread's timing across both spreads and prepare the
// continuation spread now. activate and revealContinuationSpread then reuse these — one
// prepare path, no synchronous rebuild or redraw on the critical path.
const previewSpreads = Array.isArray(previewSpread.previewSpreads) ? previewSpread.previewSpreads : null;
const startIndex = Math.max(0, Number(previewSpread.index || 0));
const continuationSpread = previewSpreads
? (previewSpreads
.filter(spread => spread
&& Number(spread.index) > startIndex
&& this.getBlockRevealSides(spread, sentence.blockId).length > 0)
.sort((a, b) => Number(a.index) - Number(b.index))[0] || null)
: null;
const revealDetail = this.createRevealDetail(sentence, previewSpread, 'prepare');
const texturePlan = await this.textureRenderer.prepareRevealBlock(
continuationSpread ? { ...revealDetail, previewSpreads } : revealDetail,
{ phase: 'prepare', publishEvent: false }
);
if (continuationSpread) {
await this.textureRenderer.prepareContinuationRevealPlan({
...revealDetail,
previewSpreads,
continuationSpread
});
}
const targetSpreadIndex = Math.max(0, Number(previewSpread.index || 0));
const currentSpreadIndex = this.getVisibleSpreadIndex();
const revealSides = this.getBlockRevealSides(previewSpread, sentence.blockId);
const segment = {
key: `${sentence.gameId || sentence.metadata?.gameId || 'game'}:${sentence.blockId}`,
id: sentence.id,
blockId: sentence.blockId,
sentence,
generation: this.paginationGeneration,
previewSpread,
targetSpreadIndex,
currentSpreadIndex,
revealSides,
requiresPreFlip: targetSpreadIndex > currentSpreadIndex,
requiresRightFlip: revealSides.includes('right') && this.requiresRightPageFlipAfterReveal(previewSpread),
// Snapshot the reveal timings now. A reused lookahead segment can be played by
// a sentence instance whose animation timings were lost; without them the
// reveal can't be word-paced and stretches across the whole TTS.
preparedAnimation: {
wordTimings: Array.isArray(revealDetail.wordTimings) ? revealDetail.wordTimings : [],
cueTimings: Array.isArray(revealDetail.cueTimings) ? revealDetail.cueTimings : [],
totalDuration: Number(revealDetail.totalDuration || 0)
},
preparedTexturePlan: texturePlan,
preparedAt: performance.now(),
revealStartedAt: null,
revealStartedPromise: null,
resolveRevealStarted: null,
status: 'prepared'
};
segment.revealStartedPromise = new Promise(resolve => {
segment.resolveRevealStarted = resolve;
});
this.applyTexturePlan(texturePlan, segment, 'prepare');
await this.timeStage('texture-prewarm', segment, () => this.prewarmSegmentTextures(segment));
await this.assertSegmentReady(segment, 'prepare');
if (options.immediate !== true) {
await new Promise(resolve => setTimeout(resolve, 0));
}
return segment;
}
async commitSegmentSpread(segment = {}, sentence = segment.sentence) {
if (!segment || !sentence) return null;
segment.sourceSpreadIndex = Number.isFinite(Number(segment.sourceSpreadIndex))
? Math.max(0, Math.round(Number(segment.sourceSpreadIndex)))
: this.getVisibleSpreadIndex();
const activeSpread = await this.pagination.preparePendingBlock(sentence, {
includeUnrenderedHistory: true
});
segment.activeSpread = activeSpread || segment.previewSpread;
segment.targetSpreadIndex = Math.max(0, Number(segment.activeSpread?.index ?? segment.targetSpreadIndex ?? 0));
segment.revealSides = this.getBlockRevealSides(segment.activeSpread || segment.previewSpread, sentence.blockId);
// Does the block overflow onto the next spread? The committed pagination now knows
// this (during lookahead it was not yet committed), so detect it here.
const nextSpread = typeof this.pagination?.getSpread === 'function'
? this.pagination.getSpread(segment.targetSpreadIndex + 1)
: this.pagination?.spreads?.[segment.targetSpreadIndex + 1];
segment.spansToNextSpread = Boolean(nextSpread)
&& this.getBlockRevealSides(nextSpread, sentence.blockId).length > 0;
// A spanning block, or one that fills the right page, must flip to keep revealing
// its continuation rather than leaving the right page's last line to absorb the
// whole TTS while the rest pops in complete after the flip.
segment.requiresRightFlip = segment.revealSides.includes('right')
&& (segment.spansToNextSpread || this.requiresRightPageFlipAfterReveal(segment.activeSpread || segment.previewSpread));
this.recordDiagnostic('segment-commit:end', segment);
return segment.activeSpread;
}
async activatePreparedSegment(segment = {}, sentence = segment.sentence) {
if (!segment || !sentence) return null;
// Restore the reveal timings captured at prepare if the live sentence lost them,
// otherwise the reveal degrades to an area estimate spanning the whole TTS.
if (segment.preparedAnimation?.wordTimings?.length && !(sentence.animation?.wordTimings?.length)) {
sentence.animation = {
...(sentence.animation || {}),
wordTimings: segment.preparedAnimation.wordTimings,
cueTimings: segment.preparedAnimation.cueTimings,
totalDuration: segment.preparedAnimation.totalDuration
};
}
const spread = segment.activeSpread || segment.previewSpread;
let texturePlan = segment.preparedTexturePlan
? { ...segment.preparedTexturePlan, phase: 'activate' }
: null;
if (texturePlan && this.pageCache?.hasPreparedRevealPlan?.(segment.blockId)) {
this.pageCache.takePreparedRevealPlan(segment.blockId);
}
if (!texturePlan) {
const revealDetail = this.createRevealDetail(sentence, spread, 'activate');
texturePlan = await this.textureRenderer.prepareRevealBlock(revealDetail, { publishEvent: false });
}
// Reuse the spanning-aware plan prepared during lookahead — its timing already spans
// both pages. No synchronous redraw on the critical path.
segment.activeTexturePlan = texturePlan;
this.applyTexturePlan(texturePlan, segment, 'activate');
await this.assertSegmentReady(segment, 'activate');
segment.status = 'activated';
this.recordDiagnostic('segment-activate:end', segment);
return spread;
}
ensureAnimationTimings(sentence = {}) {
const existingTimings = Array.isArray(sentence.animation?.wordTimings)
? sentence.animation.wordTimings
: [];
const existingDuration = existingTimings.reduce((max, timing) => Math.max(
max,
Number(timing?.delay || 0) + Number(timing?.duration || 0)
), Number(sentence.animation?.totalDuration || 0));
const ttsDuration = Number(sentence.tts?.duration || 0);
if (existingTimings.length > 0 && (existingDuration > 0 || ttsDuration <= 0)) return;
const words = String(sentence.layoutText || sentence.text || '').match(/\S+/g) || [];
sentence.animation = this.calculateAnimationTiming(words, ttsDuration, sentence.cueMarkers || []);
}
calculateAnimationTiming(words = [], totalDuration = 0, cueMarkers = []) {
if (!Array.isArray(words) || words.length === 0) {
return {
wordTimings: [],
cueTimings: [],
totalDuration: 0
};
}
const totalChars = words.reduce((sum, word) => sum + String(word || '').length, 0);
if (totalChars === 0) {
return {
wordTimings: words.map(word => ({ word, delay: 0, duration: 0 })),
cueTimings: [],
totalDuration: 0
};
}
const msPerChar = Number(totalDuration || 0) / totalChars;
let currentDelay = 0;
const wordTimings = words.map(word => {
const duration = String(word || '').length * msPerChar;
const timing = {
word,
delay: currentDelay,
duration
};
currentDelay += duration;
return timing;
});
const cueTimings = (cueMarkers || []).map(cue => {
const wordIndex = Math.max(0, Math.min(cue.wordIndex || 0, wordTimings.length - 1));
const timing = wordTimings[wordIndex] || { delay: currentDelay };
return {
...cue,
delay: timing.delay
};
});
return {
wordTimings,
cueTimings,
totalDuration: Math.round(currentDelay)
};
}
createRevealDetail(sentence = {}, spread = null, phase = 'activate') {
return {
id: sentence.id,
blockId: sentence.blockId,
wordTimings: sentence.animation?.wordTimings || [],
cueTimings: sentence.animation?.cueTimings || [],
totalDuration: sentence.animation?.totalDuration || 0,
spread,
phase
};
}
applyTexturePlan(texturePlan = null, segment = {}, phase = 'activate') {
if (!texturePlan) {
this.pageCache?.recordProblem?.({
type: 'timeline-missing-texture-plan',
blockId: segment.blockId ?? null,
phase
});
return false;
}
document.dispatchEvent(new CustomEvent('webgl-book:page-texture-records', {
detail: {
...texturePlan,
phase: phase === 'prepare' ? 'prepare' : 'activate'
}
}));
this.recordDiagnostic(`texture-plan-applied:${phase}`, segment);
return true;
}
startRevealForSegment(segment = {}) {
if (!segment?.blockId) return false;
// Mark the renderer animation as started, then let the scene render loop —
// the single reveal clock — drive timing via the dispatched reveal-start event.
const revealStart = this.textureRenderer?.startPreparedRevealAnimation?.(segment.blockId, {
publishEvent: true
});
if (!revealStart) {
this.pageCache?.recordProblem?.({
type: 'timeline-prepared-reveal-missing',
blockId: segment.blockId
});
return false;
}
segment.revealStartedAt = performance.now();
if (typeof segment.resolveRevealStarted === 'function') {
segment.resolveRevealStarted(segment.revealStartedAt);
segment.resolveRevealStarted = null;
}
this.markBenchmark('reveal-start', segment);
this.recordDiagnostic('reveal-started', segment);
return true;
}
requiresSpreadTransition(segment = {}) {
const sourceSpread = Number.isFinite(Number(segment.sourceSpreadIndex))
? Math.max(0, Math.round(Number(segment.sourceSpreadIndex)))
: this.getVisibleSpreadIndex();
return Math.max(0, Number(segment.targetSpreadIndex || 0)) > sourceSpread;
}
requiresRightPageFlipAfterReveal(spread = {}) {
const meta = spread?.pageMeta?.right || null;
if (!meta || meta.section !== 'body' || meta.kind === 'blank' || meta.kind === 'title') return false;
const rightLines = Array.isArray(spread?.right) ? spread.right : [];
const maxLine = rightLines.reduce((max, line) => Math.max(
max,
Number(line?.pageLine || 0) + Math.max(1, Number(line?.lineCount || 1))
), 0);
return maxLine >= Math.max(1, Number(meta.linesPerPage || 25));
}
getBlockRevealSides(spread = {}, blockId = null) {
const id = String(blockId ?? '');
if (!id) return [];
return ['left', 'right'].filter((side) => {
const lines = Array.isArray(spread?.[side]) ? spread[side] : [];
return lines.some(line => String(line?.blockId ?? '') === id);
});
}
async waitForVisualCompletion(segment = {}) {
if (!segment.requiresRightFlip || !Array.isArray(segment.revealSides) || !segment.revealSides.includes('right')) {
this.recordDiagnostic('visual-completion:no-right-flip-wait', segment);
return;
}
const committed = await this.timeStage('wait-right-reveal-commit', segment, () => this.waitForPlannedRightReveal(segment));
if (!committed || this.isChoiceAwaitingPlayer()) return;
const continuationSpreadIndex = Math.max(0, Number(segment.targetSpreadIndex || this.getVisibleSpreadIndex()) + 1);
const continuationSpread = typeof this.pagination?.getSpread === 'function'
? this.pagination.getSpread(continuationSpreadIndex)
: this.pagination?.spreads?.[continuationSpreadIndex];
// If the block continues onto the next spread, that page must keep revealing the
// carried-over lines after the flip instead of appearing already complete.
const continuationSides = continuationSpread ? this.getBlockRevealSides(continuationSpread, segment.blockId) : [];
const flipped = await this.timeStage('right-page-flip', segment, () => this.requestPageFlip(1, {
reason: 'timeline-right-page-filled',
targetSpread: continuationSpreadIndex,
revealSides: continuationSides,
force: true
}));
if (flipped && continuationSides.length > 0) {
await this.timeStage('reveal-continuation', segment, () => this.revealContinuationSpread(segment, continuationSpread));
}
}
// Re-apply the active block's reveal on the spread it continues onto. The renderer
// already produces reveal regions for that spread with global (continuous) timing;
// the scene resumes the same reveal clock (the block's original start persists), so
// the carried-over lines animate in instead of popping in fully revealed.
async revealContinuationSpread(segment = {}, spread = null) {
const sentence = segment.sentence;
if (!sentence || !spread) return false;
// Reuse the continuation plan prepared during lookahead. It is always prepared when a
// block spans (createPreparedSegment), so a miss is a real bug, not a redraw cue.
const texturePlan = this.textureRenderer.takeContinuationRevealPlan(segment.blockId, spread.index);
if (!texturePlan) {
this.pageCache?.recordProblem?.({
type: 'timeline-reveal-continuation-missing',
blockId: segment.blockId,
spreadIndex: Number(spread.index ?? null)
});
return false;
}
segment.activeTexturePlan = texturePlan;
this.applyTexturePlan(texturePlan, segment, 'activate');
await this.assertSegmentReady(segment, 'activate');
this.recordDiagnostic('reveal-continuation:applied', segment);
return true;
}
// Resolve when the right page's own portion of the reveal is done — its computed
// duration elapses, the reveal commits, or the player fast-forwards — whichever comes
// first. Single timer + listeners with full cleanup, so no stray commit-timeout fires.
async waitForPlannedRightReveal(segment = {}) {
const startedAt = Number(segment.revealStartedAt)
|| await (segment.revealStartedPromise || Promise.resolve(performance.now()));
const duration = this.getRightRevealDurationMs(segment);
segment.plannedRightRevealDurationMs = duration;
this.recordDiagnostic('wait-right-reveal-planned', {
...segment,
plannedRightRevealDurationMs: duration
});
const elapsed = Math.max(0, performance.now() - Number(startedAt || performance.now()));
const remaining = Math.max(0, duration - elapsed);
const blockId = String(segment.blockId ?? '');
return new Promise((resolve) => {
let done = false;
const finish = (value) => {
if (done) return;
done = true;
clearTimeout(timer);
document.removeEventListener('webgl-book:reveal-committed', onCommit);
document.removeEventListener('webgl-book:page-reveal-fast-forward', onFastForward);
resolve(value);
};
const onCommit = (event) => {
const detail = event.detail || {};
if (detail.side !== 'right') return;
const ids = Array.isArray(detail.blockIds) ? detail.blockIds.map(value => String(value)) : [];
if (blockId && ids.length && !ids.includes(blockId)) return;
finish(true);
};
const onFastForward = () => finish(true);
const timer = setTimeout(() => finish(true), remaining);
document.addEventListener('webgl-book:reveal-committed', onCommit);
document.addEventListener('webgl-book:page-reveal-fast-forward', onFastForward);
});
}
getRightRevealDurationMs(segment = {}) {
const duration = Number(segment.activeTexturePlan?.reveal?.right?.durationMs
?? segment.preparedTexturePlan?.reveal?.right?.durationMs
?? 0);
if (Number.isFinite(duration) && duration > 0) return duration;
return Math.max(1, Number(segment.sentence?.animation?.totalDuration || 1));
}
async requestPageFlip(direction = 1, options = {}) {
if (this.isChoiceAwaitingPlayer()) return false;
const flipPlan = await this.prepareFlipPlan(direction, options);
await this.assertSegmentReady({
blockId: options.blockId ?? null,
targetSpreadIndex: options.targetSpread,
revealSides: []
}, 'flip');
const sceneControl = this.scene?.sceneControl || null;
if (typeof sceneControl?.prewarmPageFlip !== 'function' || typeof sceneControl?.startPreparedPageFlip !== 'function') {
this.pageCache?.recordProblem?.({
type: 'timeline-scene-flip-api-missing',
targetSpread: flipPlan.targetSpread,
reason: options.reason || 'timeline'
});
return false;
}
const scenePrewarm = await sceneControl.prewarmPageFlip(direction, {
targetSpread: flipPlan.targetSpread,
reason: options.reason || 'timeline'
});
const started = sceneControl.startPreparedPageFlip(direction, {
force: options.force === true,
reason: options.reason || 'timeline',
targetSpread: flipPlan.targetSpread,
deferRevealSides: Array.isArray(options.revealSides) ? options.revealSides : null,
flipPlan,
prewarm: scenePrewarm
});
if (!started) {
this.pageCache?.recordProblem?.({
type: 'timeline-scene-flip-start-failed',
targetSpread: flipPlan.targetSpread,
reason: options.reason || 'timeline'
});
return false;
}
return this.waitForPageFlipFinished(flipPlan.targetSpread, { alreadyStarted: true });
}
async prepareFlipPlan(direction = 1, options = {}) {
const currentSpread = this.getVisibleSpreadIndex();
const targetSpread = Number.isFinite(Number(options.targetSpread))
? Math.max(0, Math.round(Number(options.targetSpread)))
: Math.max(0, currentSpread + Math.sign(Number(direction || 0)));
const prewarm = await this.pageCache?.prewarmNavigationWindow?.({
currentSpread,
targetSpread,
endSpread: Math.max(0, Number(this.pagination?.spreads?.length || 1) - 1),
getPageMetaForIndex: this.getPageMetaForIndex,
recordMiss: false
});
const sourceSide = direction > 0 ? 'right' : 'left';
const backSide = direction > 0 ? 'left' : 'right';
const sourcePageIndex = currentSpread * 2 + (sourceSide === 'right' ? 1 : 0);
const backPageIndex = targetSpread * 2 + (backSide === 'right' ? 1 : 0);
const plan = {
direction,
currentSpread,
targetSpread,
sourceSide,
backSide,
sourcePageMeta: this.getPageMetaForIndex(sourcePageIndex),
backPageMeta: this.getPageMetaForIndex(backPageIndex),
prewarm,
createdAt: performance.now()
};
this.markBenchmark('flip-plan-ready', plan);
this.recordDiagnostic('flip-plan-ready', {
...plan,
targetSpreadIndex: targetSpread
});
return plan;
}
async prewarmSegmentTextures(segment = {}) {
if (!this.pageCache || typeof this.pageCache.prewarmNavigationWindow !== 'function') return null;
const targetSpread = Math.max(0, Number(segment.targetSpreadIndex || 0));
const endSpread = Math.max(targetSpread, Math.max(0, Number(this.pagination?.spreads?.length || 1) - 1));
const result = await this.pageCache.prewarmNavigationWindow({
currentSpread: this.getVisibleSpreadIndex(),
targetSpread,
endSpread,
getPageMetaForIndex: this.getPageMetaForIndex,
recordMiss: false
});
segment.textureWindowReady = true;
segment.textureWindowSpreadCount = result ? Object.keys(result).length : 0;
return result;
}
collectRequiredPageMetas(segment = {}, phase = 'play') {
if (phase === 'prepare') {
return this.collectTexturePlanPageMetas(segment.preparedTexturePlan);
}
if (phase === 'activate' || phase === 'play') {
return this.collectTexturePlanPageMetas(segment.activeTexturePlan || segment.preparedTexturePlan);
}
const currentSpread = this.getVisibleSpreadIndex();
const targetSpread = Number.isFinite(Number(segment.targetSpreadIndex))
? Math.max(0, Math.round(Number(segment.targetSpreadIndex)))
: currentSpread;
return Array.from(new Set([currentSpread, targetSpread]))
.flatMap(spread => [
this.getPageMetaForIndex(spread * 2),
this.getPageMetaForIndex(spread * 2 + 1)
]);
}
collectTexturePlanPageMetas(texturePlan = null) {
const pageMeta = texturePlan?.pageMeta || {};
const records = Array.isArray(texturePlan?.records) ? texturePlan.records : [];
const metas = records
.map(record => record?.pageMeta || pageMeta?.[record?.side])
.filter(meta => meta && Number.isFinite(Number(meta.pageIndex)));
['left', 'right'].forEach((side) => {
const meta = pageMeta?.[side];
if (!meta || !Number.isFinite(Number(meta.pageIndex))) return;
if (metas.some(existing => Number(existing.pageIndex) === Number(meta.pageIndex))) return;
metas.push(meta);
});
return metas;
}
async assertSegmentReady(segment = {}, phase = 'play') {
if (!this.pageCache || typeof this.pageCache.ensurePageTexture !== 'function') {
this.recordDiagnostic(`cache-unavailable:${phase}`, segment);
return false;
}
const metas = this.collectRequiredPageMetas(segment, phase);
const missing = [];
await Promise.all(metas.map(async (meta) => {
const texture = await this.pageCache.ensurePageTexture(meta, {
recordMiss: true
});
if (!texture) missing.push(meta);
}));
if (missing.length > 0) {
// Surface the problem but do not throw out of the live playback path.
this.pageCache.recordProblem?.({
type: 'timeline-cache-readiness-failed',
phase,
blockId: segment.blockId ?? null,
missingPages: missing.map(meta => meta.pageIndex ?? null)
});
segment.cacheReady = false;
segment.cacheReadyPhase = phase;
return false;
}
segment.cacheReady = true;
segment.cacheReadyPhase = phase;
this.recordDiagnostic(`cache-ready:${phase}`, segment);
return true;
}
getPageMetaForIndex(pageIndex = 0) {
const index = Math.max(0, Math.round(Number(pageIndex || 0)));
const spreadIndex = Math.floor(index / 2);
const side = index % 2 === 0 ? 'left' : 'right';
const spread = typeof this.pagination?.getSpread === 'function'
? this.pagination.getSpread(spreadIndex)
: this.pagination?.spreads?.[spreadIndex];
const metrics = this.textureRenderer?.metrics || {};
if (!spread) {
return {
pageIndex: index,
width: metrics.width,
height: metrics.height,
kind: 'blank',
section: index < 3 ? 'frontmatter' : 'body',
pageNumber: null,
omitPageNumber: true
};
}
const source = spread?.pageMeta?.[side] || {};
return {
...source,
pageIndex: index,
width: metrics.width,
height: metrics.height,
kind: source.kind || (index < 3 ? 'blank' : 'content'),
section: source.section || (index < 3 ? 'frontmatter' : 'body')
};
}
waitForPageFlipFinished(targetSpread = null, options = {}) {
return new Promise(resolve => {
let started = options.alreadyStarted === true;
let resolved = false;
const expectedSpread = Number.isFinite(Number(targetSpread))
? Math.max(0, Math.round(Number(targetSpread)))
: null;
const cleanup = () => {
document.removeEventListener('webgl-book:page-flip-started', onStarted);
document.removeEventListener('webgl-book:page-flip-finished', onFinished);
clearTimeout(timeoutId);
};
const finish = (value) => {
if (resolved) return;
resolved = true;
cleanup();
resolve(value);
};
const matches = (detail = {}) => {
if (expectedSpread === null) return true;
const spread = Number(detail.targetSpread);
return Number.isFinite(spread) && Math.max(0, Math.round(spread)) === expectedSpread;
};
const onStarted = (event) => {
if (matches(event.detail || {})) started = true;
};
const onFinished = (event) => {
if (matches(event.detail || {})) finish(true);
};
const timeoutId = setTimeout(() => {
this.pageCache?.recordProblem?.({
type: 'timeline-page-flip-timeout',
targetSpread: expectedSpread,
started
});
finish(false);
}, 2600);
document.addEventListener('webgl-book:page-flip-started', onStarted);
document.addEventListener('webgl-book:page-flip-finished', onFinished);
});
}
getVisibleSpreadIndex() {
const sceneSpread = this.scene?.getVisibleSpreadIndex?.();
if (Number.isFinite(Number(sceneSpread))) return Math.max(0, Math.round(Number(sceneSpread)));
if (Number.isFinite(Number(this.visibleSpreadIndex))) return Math.max(0, Math.round(Number(this.visibleSpreadIndex)));
return Math.max(0, Math.round(Number(this.pagination?.currentSpreadIndex || 0)));
}
isChoiceAwaitingPlayer() {
return document.documentElement.dataset.choiceAwaiting === 'true'
|| document.body?.dataset?.choiceAwaiting === 'true'
|| Boolean(document.querySelector('#choice_menu:not([hidden]) .choice, #choice_menu.visible .choice'));
}
recordDiagnostic(type, segment = {}) {
this.timelineDiagnostics.push({
type,
blockId: segment.blockId ?? null,
spreadIndex: segment.targetSpreadIndex ?? null,
status: segment.status || null,
revealSides: Array.isArray(segment.revealSides) ? segment.revealSides : [],
plannedRightRevealDurationMs: Number.isFinite(Number(segment.plannedRightRevealDurationMs))
? Math.round(Number(segment.plannedRightRevealDurationMs))
: undefined,
at: Math.round(performance.now())
});
while (this.timelineDiagnostics.length > 200) this.timelineDiagnostics.shift();
document.documentElement.dataset.webglBookTimeline = type;
}
markBenchmark(stage, detail = {}, startedAt = null) {
const now = performance.now();
const entry = {
stage,
blockId: detail.blockId ?? null,
spreadIndex: detail.targetSpreadIndex ?? detail.spreadIndex ?? detail.targetSpread ?? null,
durationMs: Number.isFinite(Number(startedAt)) ? Math.round((now - Number(startedAt)) * 100) / 100 : null,
at: Math.round(now),
detail: {
status: detail.status || null,
revealSides: Array.isArray(detail.revealSides) ? detail.revealSides : undefined,
reason: detail.reason || null,
side: detail.side || null,
pageFlipAfterReveal: detail.pageFlipAfterReveal === true
}
};
this.benchmarkEntries.push(entry);
while (this.benchmarkEntries.length > 240) this.benchmarkEntries.shift();
document.documentElement.dataset.webglBookBenchmark = JSON.stringify(this.benchmarkEntries.slice(-40));
return entry;
}
async timeStage(stage, detail = {}, callback = null) {
const startedAt = performance.now();
this.markBenchmark(`${stage}:start`, detail);
try {
const result = await callback?.();
this.markBenchmark(`${stage}:end`, detail, startedAt);
return result;
} catch (error) {
this.markBenchmark(`${stage}:error`, {
...detail,
reason: error?.message || String(error)
}, startedAt);
throw error;
}
}
getRuntimeState() {
return {
activeBlockId: this.activeSegment?.blockId ?? null,
preparedSegmentCount: this.preparedSegments.size,
paginationGeneration: this.paginationGeneration,
visibleSpreadIndex: this.visibleSpreadIndex,
diagnostics: this.timelineDiagnostics.slice(-20),
benchmark: this.benchmarkEntries.slice(-40)
};
}
}
const bookPlaybackTimeline = new BookPlaybackTimelineModule();
export { bookPlaybackTimeline as BookPlaybackTimeline };
if (window.moduleRegistry) {
window.moduleRegistry.register(bookPlaybackTimeline);
}
window.BookPlaybackTimeline = bookPlaybackTimeline;