Fix WebGL reveal timing and flip texture readiness

scripts/check-webgl-book-lab.js

@@ -190,10 +190,11 @@ const checks = [
     ['texture renderer marks page canvases with content versions before cache writes', /pageContentVersions/.test(textureRendererSource) && /buildPublishPageMeta/.test(textureRendererSource) && /completenessScore: \(maxBlockId \* 1000\) \+ lineCount/.test(textureRendererSource)],
     ['texture store queues newer same-page cache writes instead of dropping them', /storePageCanvas/.test(webglPageCacheSource) && /isOlderPageMeta/.test(webglPageCacheSource) && /const previousWrite = pending\?\.promise \|\| Promise\.resolve\(\)/.test(webglPageCacheSource) && /pendingPageWrites\.set\(key, \{[\s\S]*pageMeta: \{ \.\.\.\(pageMeta \|\| \{\}\) \}/.test(webglPageCacheSource)],
     ['webgl texture store resident cache reuses newest page version for older readiness requests', /isOlderPageMeta/.test(webglPageCacheSource) && /getResidentTextureForMeta/.test(webglPageCacheSource) && /if \(!resident\) return null/.test(webglPageCacheSource) && !/if \(!resident \|\| this\.isOlderPageMeta\(pageMeta, resident\.pageMeta\)\) return null/.test(webglPageCacheSource)],
-    ['webgl flip page is a two-sided body using paper-thickness constants', /flipPageBackSurface/.test(source) && /flipPageEdge/.test(source) && /new THREE\.Mesh\(geometry, \[\s*materials\.flipPageSurface,\s*materials\.flipPageBackSurface,\s*materials\.flipPageEdge\s*\]\)/.test(source) && /PROCEDURAL_BOOK\.SHEET_THICKNESS_MODEL/.test(source) && /geometry\.addGroup\(0, topIndices\.length, 0\)/.test(source)],
+    ['webgl flip page is a two-sided body using paper-thickness constants', /flipPageBackSurface/.test(source) && /flipPageEdge/.test(source) && /new THREE\.Mesh\(geometry, \[\s*materials\.flipPageSurface,\s*materials\.flipPageBackSurface,\s*materials\.flipPageEdge\s*\]\)/.test(source) && /PROCEDURAL_BOOK\.SHEET_THICKNESS_MODEL/.test(source) && /const topMaterialIndex = direction > 0 \? 1 : 0/.test(source) && /const bottomMaterialIndex = direction > 0 \? 0 : 1/.test(source) && /geometry\.addGroup\(0, topIndices\.length, topMaterialIndex\)/.test(source) && /geometry\.addGroup\(topIndices\.length, bottomIndices\.length, bottomMaterialIndex\)/.test(source)],
     ['webgl animated page front and back maps are independently switchable before animation starts', /materials\.flipPageBackSurface = materials\.flipPageSurface\.clone\(\)/.test(source) && /materials\.flipPageSurface\.map = sourceTexture/.test(source) && /materials\.flipPageBackSurface\.map = backTexture \|\| getBlankPageTexture\(\)/.test(source) && /flip\.sourceTexture = sourceTexture/.test(source) && /flip\.backTexture = backTexture \|\| getBlankPageTexture\(\)/.test(source)],
     ['webgl flip preflight exposes texture side and orientation invariants for browser tests', /lastFlipTexturePreflight/.test(source) && /sourceTextureMatchesBackTexture/.test(source) && /targetBackSide/.test(source) && /getRuntimeInvariants/.test(source)],
-    ['webgl animated page back face uses destination-side page UV orientation', /pageUvForSide\(targetSide, u, v\)/.test(source) && /pageUvForSide\(sourceSide, u, v\)/.test(source) && /side < 0 \? 1 - u : u/.test(source)],
+    ['webgl animated page maps source and destination textures to direction-aware physical sides', /const topPageSide = direction > 0 \? targetSide : sourceSide/.test(source) && /const bottomPageSide = direction > 0 \? sourceSide : targetSide/.test(source) && /topRow\.push\(push\(point, pageThickness, pageUvForSide\(topPageSide, u, v\)\)\)/.test(source) && /bottomRow\.push\(push\(point, 0, pageUvForSide\(bottomPageSide, u, v\)\)\)/.test(source) && /side < 0 \? 1 - u : u/.test(source) && /y: v/.test(source)],
+    ['webgl flip prewarm prepares current and target spread texture records before cache lookup', /prepareSpreadTextureRecordsForFlip\(currentSpread\)/.test(source) && /prepareSpreadTextureRecordsForFlip\(nextSpread\)/.test(source) && /function prepareSpreadTextureRecordsForFlip/.test(source) && /spreadTextureRecordsReady\(spread\)/.test(source) && /window\.BookTextureRenderer\.drawSpread\(spread, \['left', 'right'\], \{[\s\S]*phase: 'prepare'/.test(source)],
     ['webgl animated page reuses geometry buffers during flips', /function updateFlippingPageGeometry/.test(source) && /position\.needsUpdate = true/.test(source) && /updateFlippingPageGeometry\(flip\.mesh\.geometry, surface\)/.test(source) && !/flip\.mesh\.geometry\.dispose\(\);\s*flip\.mesh\.geometry = geometry;/.test(methodBody(source, 'setActivePageGeometry'))],
     ['webgl scene targets 60fps with browser-frame scheduling live mirror and static heavy refresh', /const targetFrameDurationMs = 1000 \/ 60/.test(source) && /this\.targetFrameDurationMs = 1000 \/ 60/.test(textureRendererSource) && /requestAnimationFrame\(animate\)/.test(source) && /const refreshStaticSceneBuffers = staticSceneBuffersDirty \|\| activeFlips\.length > 0/.test(source) && /updateTableReflection\(\);/.test(source) && /mirrorRefreshesEveryFrame: true/.test(source) && !/setTimeout\(animate/.test(source)],
     ['webgl scene lowers mirror target and caps table film maps to 2k', /const reflectionPixelRatio = 1/.test(source) && /const tableReflectionBaseWidth = 2048/.test(source) && /const tableReflectionBaseHeight = 1152/.test(source) && /tableDustTexture = loadUtilityTexture\('\/assets\/webgl\/table_dust_4k\.png', \{ maxSize: 2048 \}\)/.test(source) && /tableGreaseTexture = loadUtilityTexture\('\/assets\/webgl\/table_grease_4k\.png', \{ maxSize: 2048 \}\)/.test(source)],
@@ -209,6 +210,12 @@ const checks = [
     ['game loop persists webgl book state in save slots', /webglBookState: this\.getWebGLBookState\(\)/.test(fs.readFileSync(path.join(__dirname, '..', 'public', 'js', 'game-loop-module.js'), 'utf8')) && /applyWebGLBookState\(browserSave\.webglBookState\)/.test(fs.readFileSync(path.join(__dirname, '..', 'public', 'js', 'game-loop-module.js'), 'utf8'))],
     ['webgl right-page reveal records arm a durable autoplay-targeted flip without bypassing choices', /handleRevealCommittedForPageFlip/.test(source) && /pageFlipAfterReveal/.test(textureRendererSource) && /tryStartPendingRightPageFlip/.test(source) && /pendingRightPageFlipAutoplay/.test(source) && /const targetSpread = Math\.max\(0, Math\.round\(Number\(bookPaginationState\.spreadIndex \|\| 0\)\) \+ 1\)/.test(source) && /force: options\.force === true \|\| pendingRightPageFlipAutoplay/.test(source) && /isChoiceAwaitingPlayer/.test(source) && /pendingRightPageFlip = true/.test(source)],
     ['webgl reveal clock follows absolute playback time and continues across page flips', /activeRevealBlockStarts/.test(source) && /state\.visualElapsedMs = Math\.max\(0, now - state\.startedAt\)/.test(source) && !/Math\.min\(revealFrameDeltaMs, targetFrameDurationMs\)/.test(source) && /prewarmFlipTextures\(1, targetSpread\)/.test(source)],
+    ['webgl line reveal timing uses TTS word spans instead of stretching split page fragments', /lineWordCount/.test(bookPaginationSource) && /blockWordStart/.test(textureRendererSource) && /blockWordCount/.test(textureRendererSource) && /getLineTimingFromWords/.test(textureRendererSource) && /const canUseLineWordSpans/.test(textureRendererSource)],
+    ['webgl flip completion defers book rebuild out of the final animation frame', /scheduledBookRebuildFrame/.test(source) && /function scheduleBookRebuild/.test(source) && /syncReadingProgressToCurrentPage\(\{[\s\S]*rebuild: 'defer'[\s\S]*reason: 'page-flip-finished'/.test(source)],
+    ['webgl ordinary flip near-end uses resident target textures instead of renderer redraw', /applyResidentSpreadTextures\(targetSpread, 'page-flip-near-end'\)/.test(source) && /function applyResidentSpreadTextures/.test(source) && /residentSpreadTextures:applied/.test(source) && /spreadUpdate:skip-during-flip/.test(textureRendererSource)],
+    ['webgl timeline recalculates placeholder zero-duration reveal timings from TTS duration', /existingTimings/.test(bookPlaybackTimelineSource) && /existingDuration/.test(bookPlaybackTimelineSource) && /ttsDuration/.test(bookPlaybackTimelineSource) && /existingTimings\.length > 0 && \(existingDuration > 0 \|\| ttsDuration <= 0\)/.test(bookPlaybackTimelineSource)],
+    ['webgl playback coordinator rejects placeholder zero-duration reveal timings', /timingDuration/.test(playbackCoordinatorSource) && /ttsDuration/.test(playbackCoordinatorSource) && /timingDuration <= 0 && ttsDuration > 0/.test(playbackCoordinatorSource) && /sentence\.animation = \{[\s\S]*wordTimings,[\s\S]*totalDuration: calculated\.totalDuration/.test(playbackCoordinatorSource)],
+    ['texture renderer derives reveal regions from the just-drawn preview spread before committed pagination', /if \(this\.currentSpread\) sourceSpreads\.push\(this\.currentSpread\)/.test(textureRendererSource) && /this\.pagination\.spreads\.forEach/.test(textureRendererSource) && /Number\(spread\.index\) === Number\(this\.currentSpread\.index\)/.test(textureRendererSource)],
     ['texture renderer preloads every spread touched by an active reveal block', /preloadAdditionalRevealSpreads/.test(textureRendererSource) && /spreadContainsBlock/.test(textureRendererSource) && /this\.drawSpread\(spread, \['left', 'right'\], \{ phase: 'prepare' \}\)/.test(textureRendererSource) && /this\.activeAnimations\.has\(id\)/.test(textureRendererSource)],
     ['webgl visible spread state ignores future prepared publishes before flip', /spreadUpdate:deferred-future-unrendered/.test(source) && /incomingSpreadIndex > Math\.max\(0, Number\(bookPaginationState\.spreadIndex/.test(source) && /this\.drawSpread\(this\.currentSpread, \['left', 'right'\], \{ phase: 'prepare' \}\)/.test(textureRendererSource)],
     ['3D overflow reveal preloads target spread before forced page flip', /createRevealDetail\(sentence, previewSpread, 'prepare'\)/.test(bookPlaybackTimelineSource) && /this\.textureRenderer\.prepareRevealBlock\(revealDetail, \{[\s\S]*phase: 'prepare'[\s\S]*publishEvent: false/.test(bookPlaybackTimelineSource) && /this\.prewarmSegmentTextures\(segment\)/.test(bookPlaybackTimelineSource) && /this\.assertSegmentReady\(segment, 'prepare'\)/.test(bookPlaybackTimelineSource) && /reason: 'timeline-preplay-spread-transition'/.test(bookPlaybackTimelineSource)],