Add DOM globals polyfill + native AbortController for Playground by bkaradzic-microsoft · Pull Request #1708 · BabylonJS/BabylonNative

bkaradzic-microsoft · 2026-05-18T16:35:40Z

Wires up native AbortController and adds JS polyfills for TextEncoder + PointerEvent so playgrounds depending on DOM globals stop ReferenceError'ing.

Changes:

New Apps/Playground/Scripts/dom_polyfill.js - self-detecting TextEncoder + PointerEvent polyfills.
Apps/Playground/Shared/AppContext.cpp - calls Babylon::Polyfills::AbortController::Initialize(env); loads dom_polyfill.js after file_polyfill.js.
Apps/Playground/CMakeLists.txt - adds dom_polyfill.js to SCRIPTS list; links AbortController plugin.
Apps/Playground/Android/BabylonNative/CMakeLists.txt - adds PRIVATE AbortController to BabylonNativeJNI link list (without this, Android builds fail with missing header - verified via CI).
Apps/Playground/Scripts/validation_native.js - extends document shim with createEvent + dispatchEvent.
Apps/Playground/Scripts/config.json - re-enables 1 test (idx 342).

Note: Polyfill foundation. Remaining affected playground tests need native `dispatchEvent` on canvas / `Image` polyfill / async-module support - out of scope here.

Landing context

This PR is one of 7 splits from the proven CI-green combined preview in draft PR #1702 (see #1702 for the full intended end-state and verified CI run 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:

Fix ExternalTexture_OpenGL throw-stubs to avoid MSVC C4702 under /WX #1703 - ExternalTexture C4702 build fix
Document accurate root cause for post-#1695 pixel-diff fallouts #1704 - config.json reason rewrites (5 entries)
Document accurate root cause for 17 subtle pixel-diff tests #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:

Bump JsRuntimeHost for File/FileReader polyfill (re-enables 19 GLTF/OBJ tests) #1706 - File/Blob/FileReader polyfill (largest test impact: 19 re-enables)
Add fetch() polyfill over XMLHttpRequest for Playground #1707 - fetch polyfill
Add DOM globals polyfill + native AbortController for Playground #1708 - DOM globals + native AbortController + Android CMake link
Add cubemap auto-expand polyfill for Playground (re-enables 7 PBR tests) #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.

…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>

Copilot

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds missing DOM-like globals to the Playground JS host and wires up native AbortController so DOM-dependent playgrounds/tests stop throwing ReferenceError.

Changes:

Adds a self-detecting TextEncoder + PointerEvent polyfill script and loads it in the Playground startup sequence.
Initializes and links the native AbortController polyfill in Playground (including Android JNI link fix).
Extends the validation runner’s document shim with createEvent/dispatchEvent and re-enables one previously excluded test.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Apps/Playground/Shared/AppContext.cpp	Initializes native `AbortController` and loads `dom_polyfill.js` during startup.
Apps/Playground/Scripts/validation_native.js	Expands the `document`/element shims to support event creation/dispatch used by tests.
Apps/Playground/Scripts/dom_polyfill.js	New polyfills for `TextEncoder` and `PointerEvent` when absent.
Apps/Playground/Scripts/config.json	Re-enables one previously excluded serialization test.
Apps/Playground/CMakeLists.txt	Packages `dom_polyfill.js` and links `AbortController` into Playground.
Apps/Playground/Android/BabylonNative/CMakeLists.txt	Links `AbortController` into `BabylonNativeJNI` to fix Android builds.

- Replace `new Function('return this')` with a non-eval globalThis/self/ window/global resolution chain; keep the Function-constructor trick only as a last-resort fallback for runtimes that ship none of the standard globals. - TextEncoder.prototype.encodeInto: normalize `input` (undefined -> empty string) before computing `read`, so the returned read count stays consistent with the bytes written by `encode()` (previously `String(undefined).length` returned 9 for a zero-byte write). - PointerEvent.cancelable: default to `false` (DOM spec EventInit default) instead of `true`; callers that need a cancelable event must pass `cancelable: true` explicitly. Refs PR BabylonJS#1708. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

ryantrem

I guess this makes the tests work, but if a consumer tried to use the same things in their own app, they wouldn't work. Is that really the state we want to be in, or we want to know what things don't work because they aren't polyfilled? I would have thought we would either document these features don't work because we don't polyfill, or we add native polyfills for them.

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**.

…interEvent polyfills Addresses Ryan's review (pullrequestreview-4312723810): > I would have thought we would either document these features don't > work because we don't polyfill, or we add native polyfills for them. The previous version of this PR added a Playground-only dom_polyfill.js that injected TextEncoder and PointerEvent shims onto the global object. That worked for the Playground but every other app embedding Babylon Native against Chakra would have had to independently re-discover and ship the same workaround. Move both into proper C++ polyfill libraries under Polyfills/ with the same Initialize(Napi::Env) shape as the existing Polyfills/TextDecoder (the canonical reference for the pattern in jsruntimehost). Now any BN consumer that links them and calls Initialize() gets the same behaviour for free. - Polyfills/TextEncoder/ - Napi::ObjectWrap implementation of the WHATWG Encoding Standard TextEncoder surface: encoding accessor (always utf-8), encode(input) returning a fresh Uint8Array of UTF-8 bytes via Napi::String::Utf8Value() (the engine does the UTF-16 to UTF-8 conversion natively, which is well-tested across all N-API surfaces), and encodeInto(source, destination) which walks the UTF-8 byte stream a code-point at a time, stops cleanly on a code-point boundary when the destination fills up, and derives the spec-required UTF-16 read code-unit count from the UTF-8 leading-byte bit pattern (1 code unit for 1/2/3-byte sequences, 2 for the surrogate pair encoded by a 4-byte sequence). Avoids Utf16Value() entirely to sidestep N-API shim quirks. - Polyfills/PointerEvent/ - Napi::ObjectWrap implementation of the W3C Pointer Events Level 3 surface. The constructor materialises the same ~35 MouseEvent + PointerEvent own properties on the receiver that the prior JS shim used (matching defaults: cancelable = false per DOM EventInit spec, pressure = 0.5, isPrimary = true unless explicitly disabled, etc.) and exposes preventDefault / stopPropagation / stopImmediatePropagation / getModifierState / getCoalescedEvents / getPredictedEvents as InstanceMethods. CMake / wiring: - Top-level CMakeLists.txt: add BABYLON_NATIVE_POLYFILL_TEXTENCODER and BABYLON_NATIVE_POLYFILL_POINTEREVENT options (default ON). - Polyfills/CMakeLists.txt: add_subdirectory for each, guarded by their option. - Apps/Playground/CMakeLists.txt and Apps/Playground/Android/BabylonNative/CMakeLists.txt: PRIVATE link TextEncoder + PointerEvent so AppContext.cpp can use the published headers on every platform. - Apps/Playground/Shared/AppContext.cpp: include the new headers, call TextEncoder::Initialize(env) and PointerEvent::Initialize(env) inside the runtime Dispatch lambda right after the existing TextDecoder::Initialize call (before Babylon.js scripts are loaded), and drop the LoadScript for dom_polyfill.js now that the shims are part of the runtime itself. - Delete Apps/Playground/Scripts/dom_polyfill.js (no longer used). Verified locally on Chakra build (build/win32 RelWithDebInfo, headless): - 'Serialize scene without materials' (the test the prior JS shim was added to re-enable) validates with 248 px diff - same as before. - 'GLTF Serializer multimaterial with raw texture' validates with 891 px diff (matches the JS-shim baseline exactly). - EXR Loader, Native Canvas, GUI Input Test all behave identically to the JS-shim baseline (validated / skipped same as before). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…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

[Reviewed by Copilot on behalf of @bghgary]

TextEncoder belongs in JsRuntimeHost. No DOM polyfills.

bghgary · 2026-05-29T21:00:11Z

@@ -0,0 +1,17 @@
+#pragma once


TextEncoder belongs in JsRuntimeHost alongside TextDecoder (also WHATWG Encoding Standard). Splitting them across repos means non-BN consumers can't get TextEncoder without duplicating.

bghgary · 2026-05-29T21:00:11Z

@@ -0,0 +1,21 @@
+#pragma once


We shouldn't polyfill DOM types. BabylonNative isn't a browser; DeviceInputSystem already abstracts input. Let's discuss offline before adding this.

bkaradzic-microsoft and others added 2 commits May 15, 2026 21:27

Copilot AI review requested due to automatic review settings May 18, 2026 16:35

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bkaradzic-microsoft requested review from CedricGuillemet, bghgary and ryantrem May 18, 2026 16:42

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bkaradzic-microsoft force-pushed the weekend/tpc-1579-dom-globals branch from c98d68d to 2101ef8 Compare May 27, 2026 22:08

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Add DOM globals polyfill + native AbortController for Playground#1708

Add DOM globals polyfill + native AbortController for Playground#1708
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bkaradzic-microsoft commented May 18, 2026 •

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bkaradzic-microsoft commented May 18, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Note: Polyfill foundation. Remaining affected playground tests need native dispatchEvent on canvas / Image polyfill / async-module support - out of scope here.

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bkaradzic-microsoft commented May 18, 2026 •

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Note: Polyfill foundation. Remaining affected playground tests need native `dispatchEvent` on canvas / `Image` polyfill / async-module support - out of scope here.