[draft] Playground polyfills: File/FileReader, DOM, fetch, cubemap .env, Chakra ES2019 by bkaradzic-microsoft · Pull Request #1702 · BabylonJS/BabylonNative

bkaradzic-microsoft · 2026-05-18T14:57:48Z

Rebased onto latest master. Several pieces of the original combined branch have landed independently and were dropped as superseded; the genuine remaining playground-polyfill features stay.

Kept (5 commits, all unique to this branch)

DOM polyfills (dom_polyfill.js: TextEncoder, PointerEvent, AbortController, document.createEvent) + Android JNI link for the AbortController polyfill.
fetch() polyfill (fetch_polyfill.js).
Cubemap .env fallback (cube_texture_polyfill.js) + re-enable of 7 cubemap tests.
Chakra ES2020→ES2019 syntax-repair polyfill (es2019_transpile.js).

All four polyfills are wired through AppContext.cpp's script loader (transpiler first, then DOM/fetch; the cubemap patch loads after Babylon since it patches NativeEngine.createCubeTexture) and registered in Apps/Playground/CMakeLists.txt.

Dropped (now in `master`)

File/FileReader polyfill + 19 GLTF/OBJ serializer re-enables + the 5 follow-up GLTF-Serializer-on-OpenGL config.json exclusion tweaks — master landed the File/FileReader support in Bump JsRuntimeHost for File/FileReader polyfill (re-enables 19 GLTF/OBJ tests) #1706 as a native JsRuntimeHost bump (not a file_polyfill.js script), and that change already carries the identical test re-enables and the same OpenGL exclusion entries/reason strings this branch added. All five of this branch's File-related commits were therefore dropped as superseded.
OpenGL ExternalTexture stub — master landed the reviewed fix in Fix ExternalTexture_OpenGL throw-stubs to avoid MSVC C4702 under /WX #1703 (#pragma warning(disable:4702) over the throwing stubs), superseding this branch's "inert default-value stubs" approach on the same file.
Post-SPIRV-Cross-bump pixel-diff triage + the BN-rendered reference-image re-bakes — master documented the accurate root causes in Document accurate root cause for post-#1695 pixel-diff fallouts #1704/Document accurate root cause for 17 subtle pixel-diff tests #1705, and the two reference PNGs this branch re-baked were already reverted within the branch itself, so git dropped both as already-upstream.

config.json validates as JSON, identical structure to master apart from the cubemap re-enables and the ES2019/cubemap reason-string rewrites.

Note: the Chakra ES2019 syntax-repair polyfill remains here as part of the full intended preview, but the standalone split for it (#1709) was closed in favour of investigating @babel/standalone properly (#1711). Treat that piece as exploratory.

Per-test PIL-composite triage of all 17 ``subtle pixel-diff`` tests. None of them are deterministic-cosmetic (no re-bakes possible - all show real visible regressions). Updates the `reason` field in `Apps/Playground/Scripts/config.json` for 17 tests with accurate symptom descriptions, classifying into recurring root-cause clusters: - 9 GUI green->red color regressions (idx 160, 174, 175, 196, 197, 370, 402, 566, 587) - 4 OpenPBR analytic-lights right-column red rendering (580, 584, 587, 592) - 1 instanced billboard foliage red (169) - 1 LineEdgesRenderer extra red lines (179) - 1 Background blur red splotches (602) - 1 Clip planes GUI sliders red (182) - 1 Instanced Bones edge-AA (256, borderline) **No source changes, no test re-enables, no PNGs.** Metadata-only correction so the issue tracker reflects actionable root causes. --- ## Landing context This PR is one of **7 splits** from the proven CI-green combined preview in **draft PR #1702** (see [#1702](#1702) for the full intended end-state and verified CI run [26044922430](https://github.com/BabylonJS/BabylonNative/actions/runs/26044922430)). > Note: the original split included an 8th PR (#1709, ES2020+ -> ES2019 syntax-repair polyfill for Chakra). It was closed in favour of investigating `@babel/standalone` properly (#1711). ### Recommended landing order **Tier 1 - parallel-reviewable, no source conflicts:** 1. #1703 - ExternalTexture C4702 build fix 2. #1704 - config.json `reason` rewrites (5 entries) 3. #1705 - config.json `reason` rewrites (17 entries) **Tier 2 - sequential, each touches `Apps/Playground/CMakeLists.txt` SCRIPTS list + `Apps/Playground/Shared/AppContext.cpp` LoadScript order; rebase the next branch after the previous merges:** 4. #1706 - File/Blob/FileReader polyfill (largest test impact: 19 re-enables) 5. #1707 - fetch polyfill 6. #1708 - DOM globals + native AbortController + Android CMake link 7. #1710 - Cubemap auto-expand polyfill (loaded after babylon.max.js) ### Reference policy reminder Reference PNGs across all 7 PRs come from Babylon.js; never re-baked by BN. Combined diff: **0 PNGs**.

Per-test triage of 5 post-#1695 pixel-diff fallouts. Updates the `reason` field in `Apps/Playground/Scripts/config.json` for 3 entries to name the real BN rendering regression instead of generic "Pixel comparison fails": - idx 363 SSR2 - SSR not rendering wet floor. - idx 369 Sprites Pixel Perfect - sprite alpha-blending broken. - idx 395 soft-transparent-shadows - soft-shadow filter precision degraded. **No source changes, no test re-enables, no PNGs.** Metadata-only correction so the issue tracker reflects actionable root causes for follow-up engineering work. --- ## Landing context This PR is one of **7 splits** from the proven CI-green combined preview in **draft PR #1702** (see [#1702](#1702) for the full intended end-state and verified CI run [26044922430](https://github.com/BabylonJS/BabylonNative/actions/runs/26044922430)). > Note: the original split included an 8th PR (#1709, ES2020+ -> ES2019 syntax-repair polyfill for Chakra). It was closed in favour of investigating `@babel/standalone` properly (#1711). ### Recommended landing order **Tier 1 - parallel-reviewable, no source conflicts:** 1. #1703 - ExternalTexture C4702 build fix 2. #1704 - config.json `reason` rewrites (5 entries) 3. #1705 - config.json `reason` rewrites (17 entries) **Tier 2 - sequential, each touches `Apps/Playground/CMakeLists.txt` SCRIPTS list + `Apps/Playground/Shared/AppContext.cpp` LoadScript order; rebase the next branch after the previous merges:** 4. #1706 - File/Blob/FileReader polyfill (largest test impact: 19 re-enables) 5. #1707 - fetch polyfill 6. #1708 - DOM globals + native AbortController + Android CMake link 7. #1710 - Cubemap auto-expand polyfill (loaded after babylon.max.js) ### Reference policy reminder Reference PNGs across all 7 PRs come from Babylon.js; never re-baked by BN. Combined diff: **0 PNGs**.

…1703) Fixes MSVC C4702 (unreachable code) under `/WX` in `Plugins/ExternalTexture/Source/ExternalTexture_OpenGL.cpp` so the OpenGL TU builds cleanly without the project-wide `/wd4702` workaround. ## What changed `Plugins/ExternalTexture/Source/ExternalTexture_OpenGL.cpp` keeps the unimplemented `Impl` stubs as `throw std::runtime_error{"not implemented"}` (so callers get an unambiguous diagnostic matching every other backend's unimplemented path) and wraps the `#include "ExternalTexture_Shared.h"` line in `#pragma warning(push)/(disable: 4702)/(pop)`. The shared dispatchers instantiated by that include unconditionally call the stubs, so MSVC's flow analysis flags the dispatcher's post-call code as unreachable; the pragma suppresses C4702 only for the dispatcher code instantiated in this translation unit. Any other code in this file is still subject to `/WX` C4702 enforcement. `Plugins/ExternalTexture/CMakeLists.txt` - drop the `/wd4702` target compile option, which previously silenced C4702 across the whole target. ## Alternatives considered - **`[[noreturn]]` on the stubs**: MSVC propagates "never returns" through the shared dispatcher, which flags *more* post-call statements as unreachable. Tried and rejected (it made the warning worse). - **TU-wide `/wd4702` via `target_compile_options`**: silences any future legitimate C4702 elsewhere in the same TU, defeating `/WX`. The current localized `#pragma warning(push/pop)` block keeps the rest of the TU under `/WX` enforcement. - **Replacing the throws with inert return-default stubs**: changes product behaviour (callers would silently receive a null texture instead of a clear "not implemented" error) to work around a compiler warning. Rejected on principle. ## Verified Clean under Debug + Release + RelWithDebInfo on OpenGL (`win32-gl`, `GRAPHICS_API=OpenGLWindowsDevOnly`) and D3D11 (`win32`). --- ## Landing context This PR is one of **7 splits** from the proven CI-green combined preview in **draft PR #1702** (see [#1702](#1702) for the full intended end-state and verified CI run [26044922430](https://github.com/BabylonJS/BabylonNative/actions/runs/26044922430)). > Note: the original split included an 8th PR (#1709, ES2020+ -> ES2019 syntax-repair polyfill for Chakra). It was closed in favour of investigating `@babel/standalone` properly (#1711). ### Recommended landing order **Tier 1 - parallel-reviewable, no source conflicts:** 1. #1703 - ExternalTexture C4702 build fix 2. #1704 - config.json `reason` rewrites (5 entries) 3. #1705 - config.json `reason` rewrites (17 entries) **Tier 2 - sequential, each touches `Apps/Playground/CMakeLists.txt` SCRIPTS list + `Apps/Playground/Shared/AppContext.cpp` LoadScript order; rebase the next branch after the previous merges:** 4. #1706 - File/Blob/FileReader polyfill (largest test impact: 19 re-enables) 5. #1707 - fetch polyfill 6. #1708 - DOM globals + native AbortController + Android CMake link 7. #1710 - Cubemap auto-expand polyfill (loaded after babylon.max.js) ### Reference policy reminder Reference PNGs across all 7 PRs come from Babylon.js; never re-baked by BN. Combined diff: **0 PNGs**. --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

@bghgary

…BJ tests) (#1706) Re-enables the 19 GLTF/OBJ serializer round-trip tests that fail under BN today because the runtime is missing `File` and `FileReader`. Babylon.js code paths (`new File([blob], 'scene.glb')` followed by `LoadAssetContainerAsync(file, scene)`, which internally reads via `FileReader.readAsArrayBuffer`) need both APIs to work. The actual polyfill **lives in JsRuntimeHost** ([bkaradzic-microsoft/JsRuntimeHost @ 670084e5](bkaradzic-microsoft/JsRuntimeHost@670084e)), next to `Polyfills/Blob/`. That's the architecturally correct home — `File` and `FileReader` are standard WHATWG web APIs in the same category as the existing `XMLHttpRequest` / `URL` / `WebSocket` / `TextDecoder` / `AbortController` polyfills hosted there, and `File` is layered directly on top of `Blob`. Hosting them there means every JsRuntimeHost consumer (BN and any other embedder) gets them. > Addresses [@bghgary's review](#1706 (review)): _"this should be a proper C++ polyfill under `Polyfills/` so every consumer gets it, not a Playground-only JS script"_. **This PR (BN-side) is intentionally tiny:** - `CMakeLists.txt` — bump JsRuntimeHost `GIT_TAG` to `670084e5` and temporarily point `GIT_REPOSITORY` at the [`bkaradzic-microsoft/JsRuntimeHost`](https://github.com/bkaradzic-microsoft/JsRuntimeHost) fork until the upstream JsRuntimeHost PR is merged. Will be re-pinned to a `BabylonJS/JsRuntimeHost` commit before this PR merges. - `Apps/Playground/Shared/AppContext.cpp` — `Babylon::Polyfills::File::Initialize(env)` immediately after `Blob::Initialize(env)`. The old `LoadScript("app:///Scripts/file_polyfill.js")` line is gone. - `Apps/Playground/CMakeLists.txt` — drops `file_polyfill.js` from SCRIPTS, links the new JsRuntimeHost `File` target into the Playground binary. - `Apps/Playground/Scripts/file_polyfill.js` — deleted (308 lines of JS subsumed by the C++ polyfill in JsRuntimeHost). - `Apps/Playground/Scripts/config.json` — re-enables 19 affected tests; adds `excludedGraphicsApis: ["OpenGL"]` to 5 GLTF Serializer tests (KHR gpu instancing + 4 Camera variants) for OpenGL-specific backend issues unrelated to this polyfill. **Verified:** 19/19 affected tests pass on Win32 D3D11 Release headless without `--include-excluded` (indices 208-216, 219-226, 275-276). Remaining 9 (in the same family) fail with separate root causes — tracked separately. ## Landing sequence 1. ✅ Push JsRuntimeHost work to fork branch + this BN PR (← here, validating CI against fork branch). 2. ⏳ Open PR to `BabylonJS/JsRuntimeHost` adding `Polyfills/File/` once BN CI is green here. 3. ⏳ After the JsRuntimeHost PR merges, re-pin this BN PR's `GIT_REPOSITORY` / `GIT_TAG` back to `BabylonJS/JsRuntimeHost` at the merged SHA. 4. ⏳ Merge this BN PR. --- ## Series landing context This PR is one of **7 splits** from the proven CI-green combined preview in **draft PR #1702** (see [#1702](#1702) for the full intended end-state and verified CI run [26044922430](https://github.com/BabylonJS/BabylonNative/actions/runs/26044922430)). > Note: the original split included an 8th PR (#1709, ES2020+ -> ES2019 syntax-repair polyfill for Chakra). It was closed in favour of investigating `@babel/standalone` properly (#1711). ### Recommended landing order **Tier 1 - parallel-reviewable, no source conflicts:** 1. #1703 - ExternalTexture C4702 build fix 2. #1704 - config.json `reason` rewrites (5 entries) 3. #1705 - config.json `reason` rewrites (17 entries) **Tier 2 - sequential, each touches `Apps/Playground/CMakeLists.txt` SCRIPTS list + `Apps/Playground/Shared/AppContext.cpp` LoadScript order; rebase the next branch after the previous merges:** 4. #1706 - File/FileReader polyfill (JsRuntimeHost bump + Playground wiring; largest test impact: 19 re-enables) 5. #1707 - fetch polyfill 6. #1708 - DOM globals + native AbortController + Android CMake link 7. #1710 - Cubemap auto-expand polyfill (loaded after babylon.max.js) ### Reference policy reminder Reference PNGs across all 7 PRs come from Babylon.js; never re-baked by BN. Combined diff: **0 PNGs**. --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: Branimir Karadzic <branimirkaradzic@gmail.com>

…nt.createEvent) Playground tests that use modern browser APIs hit ReferenceErrors on the Chakra-based BN runtime because TextEncoder and PointerEvent are not part of older Chakra's built-ins. Several serializer tests also exercise document.createEvent + element.dispatchEvent shapes that the existing minimal document polyfill in validation_native.js did not cover. - Apps/Playground/Scripts/dom_polyfill.js: new self-detecting JS polyfills for TextEncoder (UTF-8 encode + encodeInto) and PointerEvent (constructor with the MouseEvent + PointerEvent surface). - Apps/Playground/Shared/AppContext.cpp + CMakeLists.txt: wire in the native AbortController polyfill from JsRuntimeHost and load dom_polyfill.js before ammo.js. - Apps/Playground/Scripts/validation_native.js: extend the existing document shim with createEvent, dispatchEvent, addEventListener and a generic-element fallback for createElement so click-event-based serializer tests can run. - Apps/Playground/Scripts/config.json: re-enable "Serialize scene without materials" (idx 342), which now validates with 248 px diff. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

AppContext.cpp includes <Babylon/Polyfills/AbortController.h> and calls Babylon::Polyfills::AbortController::Initialize(env), but the Android- specific CMakeLists at Apps/Playground/Android/BabylonNative did not add AbortController to BabylonNativeJNI's PRIVATE link libraries. The header is published only by the AbortController target, so Android CI failed with 'fatal error: Babylon/Polyfills/AbortController.h file not found'. Linux/macOS/Windows builds were fine because they use the main Apps/Playground/CMakeLists.txt which already links AbortController. Mirror the change there so Android picks up the include directory. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Implements a minimal `fetch(input, init)` polyfill in Apps/Playground that wraps XMLHttpRequest. Provides a Response-like result with `.ok`, `.status`, `.statusText`, `.url`, `.text()`, `.arrayBuffer()`, `.json()`, `.blob()`, and a `headers` stub. Self-detecting: no-op if a global `fetch` already exists; bails if XMLHttpRequest is unavailable. Wired into the Playground SCRIPTS list and loaded by AppContext before `ammo.js` / `babylon.max.js` so playground snippets that use the modern `fetch` API can run on Babylon Native's host environments (Chakra and V8), which do not provide `fetch` by default. Babylon Native's `XMLHttpRequest` only dispatches events through `addEventListener` (no `onload`/`onerror` properties) and fires `loadend` rather than `load`; the polyfill listens on `loadend` and inspects `status` to decide resolve/reject. When `responseType` is `arraybuffer`, BN's `XHR.responseText` is empty, so `.text()` decodes the array buffer directly rather than reading `responseText`.

Babylon Native's NativeEngine.createCubeTexture override only handles .env single-file cubemaps and 6-face arrays; .dds / .ktx / .ktx2 URLs fall through to a throw ("Cannot load cubemap because 6 files were not defined"). The loader-aware path used by the WebGL engine (texture loader registry lookup) is bypassed entirely. Add a JS-side polyfill that detects .dds / .ktx / .ktx2 single-URL cubemap loads and retries with the .env extension. Babylon's CI generates both .dds and .env from the same source HDR and uploads them to the same CDN path, so the swap is transparent for the Babylon-hosted environments these tests reference. On 404 (no .env counterpart exists) the polyfill re-invokes the original code path, preserving the existing throw semantics. This unblocks 7 tests that were excluded because the throw aborted the scene before any rendering could happen: idx 141 NMEGLTF idx 172 Anisotropic idx 173 Clear Coat idx 246 PBRMetallicRoughnessMaterial idx 247 PBRSpecularGlossinessMaterial idx 248 PBR idx 290 Prepass SSAO + depth of field Strip excludeFromAutomaticTesting + reason from those 7 entries in config.json. All 7 validate sub-threshold on Win32 V8 D3D11 Release without --include-excluded after the strip (pixel diff range 308..2638, well under the 2.5% threshold).

Babylon Native's Chakra-based builds parse only up to ES2019; modern Babylon.js playground snippets routinely use optional chaining (?.), nullish coalescing (??), numeric separators (1_000_000), and logical assignment (||= &&= ??=), causing 26 visual tests to fail with SyntaxError at the eval() site in validation_native.js. Add a lightweight regex-based syntax-repair polyfill loaded before babylon.max.js. The polyfill exposes __bnTranspileES2019(code) as a top-level global var. validation_native.js's new evalWithFallback helper catches SyntaxError on the first eval and retries once with the repaired source. Engines that already accept the source (V8, JSC) never hit the retry path. The polyfill is syntax-only (parse-time fix), not semantic - ?. is rewritten to . so a null target throws TypeError at runtime instead of short-circuiting to undefined. This is a deliberate trade-off: parse failures are 100% blocking; runtime TypeErrors are diagnosable and at worst surface a different bug that was previously hidden. Strip excludeFromAutomaticTesting from idx 403 (custom-handling-of-materials-for-render-target-pass) which now passes end-to-end. Updated reasons for the other 25 entries to describe their post-polyfill state: 9 hit runtime errors after parse repair, 12 hit asset/module gaps, 4 hit ES2022 syntax not covered by the polyfill (e.g. private class fields).

bkaradzic-microsoft force-pushed the weekend/all-combined branch 3 times, most recently from 0707eaf to 61da57f Compare May 18, 2026 16:00

bkaradzic-microsoft force-pushed the weekend/all-combined branch from 61da57f to b89662c Compare June 4, 2026 03:55

bkaradzic-microsoft changed the title ~~[draft] Combined weekend playground polyfills (CI smoke)~~ [draft] Playground polyfills: File/FileReader, DOM, fetch, cubemap .env, Chakra ES2019 Jun 4, 2026

bkaradzic-microsoft and others added 5 commits June 5, 2026 16:30

bkaradzic-microsoft force-pushed the weekend/all-combined branch from b89662c to b00d7c0 Compare June 5, 2026 23:31

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[draft] Playground polyfills: File/FileReader, DOM, fetch, cubemap .env, Chakra ES2019#1702

[draft] Playground polyfills: File/FileReader, DOM, fetch, cubemap .env, Chakra ES2019#1702
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bkaradzic-microsoft commented May 18, 2026 •

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Dropped (now in `master`)