Stabilize WebGL book pagination restore

scripts/check-webgl-book-lab.js

@@ -163,7 +163,7 @@ const checks = [
     ['webgl page text textures avoid mipmap generation', /function configurePageCanvasTexture/.test(source) && /texture\.minFilter = THREE\.LinearFilter/.test(source) && /texture\.generateMipmaps = false/.test(source)],
     ['webgl reveal shader masks against a base-page texture instead of flat color blocks', /bookRevealBaseMap/.test(source) && /bookRevealUseBaseMap/.test(source) && /revealBaseColor/.test(source) && /baseCanvas/.test(textureRendererSource)],
     ['webgl reveal shader masks antialiased ink and uses smooth line-dominant scan', /smoothstep\(0\.52, 0\.9, luminance\)/.test(source) && /local\.x \* 0\.96/.test(source) && /bookRevealSoftness = \{ value: 0\.025 \}/.test(source)],
-    ['webgl reveal line timings use absolute block word timing across split pages', /assignRevealTiming/.test(textureRendererSource) && /wordStart/.test(textureRendererSource) && /blockWordStart/.test(textureRendererSource) && /wordTimings\[wordStart\]/.test(textureRendererSource) && /durationMs: sideRegions\.reduce/.test(textureRendererSource)],
+    ['webgl reveal line timings use global area timing across split-page spreads', /assignRevealTiming/.test(textureRendererSource) && /sourceSpreads/.test(textureRendererSource) && /this\.pagination\?\.spreads/.test(textureRendererSource) && /spreadIndex/.test(textureRendererSource) && /totalDuration \* \(Math\.max\(1, region\.area\) \/ totalArea\)/.test(textureRendererSource) && /durationMs: sideRegions\.reduce/.test(textureRendererSource)],
     ['webgl page format reduces only outer margins from previous value', /outerBaseIn: 0\.27/.test(pageFormatSource) && /outerThicknessFactor: 0\.015/.test(pageFormatSource) && /outerMaxIn: 0\.315/.test(pageFormatSource) && /innerBaseIn: 0\.42/.test(pageFormatSource)],
     ['webgl mode enlarges and inverts DOM overlay text without touching 2D mode', /body\.webgl-mode \{[\s\S]*font-size: 18px;/.test(styleSource) && /body\.webgl-mode \.choice-list \.choice-button/.test(styleSource) && /rgba\(246, 231, 201/.test(styleSource)],
     ['webgl choice overlay hides title clutter and prevents horizontal scrollbar', /body\.webgl-mode #page_left #game_title/.test(styleSource) && /body\.webgl-mode #page_left #start_prompt/.test(styleSource) && /overflow-x: hidden/.test(styleSource) && /book\.style\.width = 'min\(44rem/.test(webglSceneSource)],
@@ -175,12 +175,13 @@ const checks = [
     ['webgl scene does not republish 3D page textures from DOM refresh events', !/addEventListener\(document, 'story:turn-start', this\.triggerTextureRefresh\)/.test(webglSceneSource) && !/addEventListener\(document, 'story:turn-complete', this\.triggerTextureRefresh\)/.test(webglSceneSource) && !/addEventListener\(document, 'story:history-updated', this\.triggerTextureRefresh\)/.test(webglSceneSource) && !/addEventListener\(document, 'input', this\.triggerTextureRefresh/.test(webglSceneSource) && !/addEventListener\(document, 'change', this\.triggerTextureRefresh/.test(webglSceneSource)],
     ['webgl scene adoptPageContent does not republish 3D page textures', !/triggerTextureRefresh/.test(methodBody(webglSceneSource, 'adoptPageContent'))],
     ['webgl book starts at progress zero', /const DEFAULT_BOOK_PROGRESS = 0;/.test(webglSceneSource) && /appInitialState\.progress \?\? '0'/.test(source)],
-    ['pagination opens with blank left and title right spread', /this\.createBlankPage\(0, \{ section: 'frontmatter' \}\)/.test(bookPaginationSource) && /this\.createTitlePage\(1\)/.test(bookPaginationSource) && /this\.createBlankPage\(2, \{ section: 'frontmatter' \}\)/.test(bookPaginationSource)],
+    ['pagination opens with blank left and title right spread', /this\.createBlankPage\(0, \{ section: 'frontmatter' \}\)/.test(bookPaginationSource) && /this\.createTitlePage\(1\)/.test(bookPaginationSource) && /this\.createBlankPage\(2, \{ section: 'frontmatter' \}\)/.test(bookPaginationSource) && /this\.pages = this\.buildPages\(\[\]\);/.test(bookPaginationSource) && /this\.currentSpreadIndex = 0;[\s\S]*this\.publish\(\{ reason: 'initial-title-spread', allowFutureUnrendered: true \}\);/.test(bookPaginationSource)],
+    ['texture renderer adopts initial pagination spread so title page is painted after loader order', /this\.currentSpread = this\.pagination\?\.getCurrentSpread\?\.\(\) \|\| \{ index: 0/.test(textureRendererSource) && /this\.drawSpread\(this\.currentSpread\);/.test(textureRendererSource)],
     ['pagination publishes page metadata and advances near the end of physical flips', /pageMeta/.test(bookPaginationSource) && /webgl-book:page-flip-near-end/.test(bookPaginationSource) && /this\.setCurrentSpread\(this\.currentSpreadIndex \+ direction\)/.test(bookPaginationSource)],
     ['texture renderer draws title page and page numbers from versioned page metadata', /drawTitlePage/.test(textureRendererSource) && /game_title/.test(textureRendererSource) && /drawPageNumber/.test(textureRendererSource) && /pageMeta: this\.buildPublishPageMeta\(sidesToPublish\)/.test(textureRendererSource)],
     ['texture renderer uses plural page margin metrics for page numbers', /this\.metrics\.margins\.bottom/.test(textureRendererSource) && !/this\.metrics\.margin\.bottom/.test(textureRendererSource)],
     ['webgl flip borrows resident page texture and blanks right stack before forward animation', /prepareStaticPageForFlip/.test(source) && /materials\.flipPageSurface\.map = sourceTexture/.test(source) && /materials\.rightPage\.map = blankTexture/.test(source) && /webgl-book:page-flip-near-end/.test(source)],
-    ['webgl flip never falls back to the opposite visible stack for target back texture', /const residentBackTexture = getResidentPageTexture\(targetBackPageIndex\)/.test(source) && /const backTexture = residentBackTexture \|\| getBlankPageTexture\(\)/.test(source) && !/oppositeMaterial\?\.map/.test(methodBody(source, 'prepareStaticPageForFlip'))],
+    ['webgl flip never falls back to the opposite visible stack for target back texture', /const prewarmedBackTexture = flip\.direction > 0 \? prewarm\?\.next\?\.left : prewarm\?\.next\?\.right/.test(source) && /const residentBackTexture = prewarmedBackTexture \|\| getResidentPageTexture\(targetBackPageIndex\)/.test(source) && /const backTexture = residentBackTexture \|\| getBlankPageTexture\(\)/.test(source) && !/oppositeMaterial\?\.map/.test(methodBody(source, 'prepareStaticPageForFlip'))],
     ['webgl page canvas metadata accepts explicit blank sides instead of retaining stale pages', /hasLeftMeta/.test(source) && /hasRightMeta/.test(source) && /Object\.prototype\.hasOwnProperty\.call\(detail\.pageMeta, 'right'\)/.test(source)],
     ['texture renderer publishes both spread sides for reveal preparation and fallback start', /this\.drawSpread\(this\.currentSpread \|\| this\.pagination\?\.getCurrentSpread\?\.\(\), \['left', 'right'\]\)/.test(textureRendererSource) && /const sides = \['left', 'right'\]/.test(textureRendererSource) && /pageMeta: prepared\.pageMeta \|\| \{\}/.test(textureRendererSource)],
     ['texture renderer marks page canvases with content versions before cache writes', /pageContentVersions/.test(textureRendererSource) && /buildPublishPageMeta/.test(textureRendererSource) && /completenessScore: \(maxBlockId \* 1000\) \+ lineCount/.test(textureRendererSource)],
@@ -188,7 +189,7 @@ const checks = [
     ['webgl resident page texture cache rejects older page versions before direct reuse', /isOlderPageTextureMeta/.test(source) && /getResidentPageTextureForMeta/.test(source) && /getResidentPageTextureForMeta\(pageMeta\)/.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) && /geometry\.addGroup\(0, topIndices\.length, 0\)/.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/.test(source) && /flip\.sourceTexture = sourceTexture/.test(source) && /flip\.backTexture = backTexture/.test(source)],
-    ['webgl animated page back face uses its own unflipped page orientation', /bottomRow\.push\(push\(point, 0, u, 1 - v\)\)/.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 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)],
@@ -205,7 +206,12 @@ const checks = [
     ['webgl right-page completion arms a durable autoplay-targeted flip without bypassing choices', /handleRevealCommittedForPageFlip/.test(source) && /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)],
     ['texture renderer preloads every spread touched by an active reveal block', /preloadAdditionalRevealSpreads/.test(textureRendererSource) && /spreadContainsBlock/.test(textureRendererSource) && /this\.drawSpread\(spread, \['left', 'right'\], \{ preloadOnly: true \}\)/.test(textureRendererSource) && /this\.activeAnimations\.has\(id\)/.test(textureRendererSource)],
+    ['webgl visible spread state ignores future unrendered prepare publishes before flip', /spreadUpdate:deferred-future-unrendered/.test(source) && /incomingSpreadIndex > Math\.max\(0, Number\(bookPaginationState\.spreadIndex/.test(source) && /this\.drawSpread\(this\.currentSpread, \['left', 'right'\], \{ preloadOnly: true \}\)/.test(textureRendererSource)],
+    ['3D overflow reveal preloads target spread before forced page flip', /previewRevealDetail/.test(uiDisplayHandlerSource) && /preloadOnly: true/.test(uiDisplayHandlerSource) && /bookTextureRenderer\.prepareRevealBlock\(previewRevealDetail, \{ preloadOnly: true \}\)/.test(uiDisplayHandlerSource) && /await this\.waitForWebGLPageFlip/.test(uiDisplayHandlerSource)],
+    ['webgl navigation buttons use visited page limit instead of future prepared pages', /maxVisitedPagePosition/.test(source) && /navigateToPagePosition\(maxVisitedPagePosition\)/.test(source) && /const navigableLimit = Math\.min\(maxVisitedPagePosition, writableLimit\)/.test(source) && !/navigateToPagePosition\(bookPaginationState\.writtenPageLimit\)/.test(source)],
+    ['webgl save restore carries visited page limit for navigation', /maxVisitedPagePosition/.test(source) && /setMaxVisitedPagePosition/.test(source) && /state\.maxVisitedPagePosition \?\? state\.pagePosition/.test(webglSceneSource)],
     ['webgl page flips require resident back textures before animation starts', /prepareStaticPageForFlip\(flip, prewarm = null\)/.test(source) && /flip-back-texture-missing/.test(source) && /return false;/.test(methodBody(source, 'prepareStaticPageForFlip')) && /flipTexturePreflight:ready/.test(source) && /if \(!prepareStaticPageForFlip\(flip, options\.prewarm \|\| null\)\) \{[\s\S]*return false;[\s\S]*\}/.test(source)],
+    ['webgl fast page flips preflight the actual target spread', /firstFlip\.targetSpread = Number\.isFinite\(Number\(options\.targetSpread\)\)/.test(source) && /if \(!prepareStaticPageForFlip\(firstFlip, options\.prewarm \|\| null\)\) return false/.test(source)],
     ['markup and 3d pagination accept full-page images', /'full'/.test(markupParserSource) && /size === 'full'/.test(bookPaginationSource)],
     ['story history can persist 3d pagination decisions', /persistPaginationMetrics/.test(bookPaginationSource) && /collectPaginationMetrics/.test(bookPaginationSource) && /pageStart/.test(storyHistorySource) && /pagination: metrics\.pagination/.test(storyHistorySource)]
 ];