monorepo + git subtree

[CedricGuillemet]

Summary

Convert BabylonNative to a self-contained monorepo using squashed Git subtree imports instead of copying dependency sources.

Repository	Prefix	Imported revision
CMakeExtensions	Dependencies/CMakeExtensions	631780e42886e5f12bfd1a5568c7395f1d657f43
AndroidExtensions	Dependencies/AndroidExtensions	2e85a8d43b89246c460112c9e5546ad54b6e87b4
bgfx.cmake	Dependencies/bgfx.cmake	9a569c775917e3dd2a8cfb8836aeddbe790a8deb
bgfx	Dependencies/bgfx	0837ead970a66875dcba37d1bd8e104db0879561
bimg	Dependencies/bimg	371d90098b1fd017cd00205979d5ef74b8c3ed62
bx	Dependencies/bx	080f466590c161664f2a3c5d21e05bd31cc9c8c8
glslang	Dependencies/glslang	284e4301e5a6b44b279635276588db7cdd942624
JsRuntimeHost	Dependencies/JsRuntimeHost	0d26362700edd52a48c38ab83b1090e53e7cfeba
SPIRV-Cross	Dependencies/SPIRV-Cross	7c8705749fc1e234119c20695f82179b30d90914
UrlLib	Dependencies/UrlLib	0c991337a1160ba7a2d062bf8e342d0a66f48dc9

bgfx, bimg, and bx are sibling subtrees because bgfx.cmake requires their source trees. Its obsolete nested gitlinks were removed.

base-n and ios-cmake intentionally remain FetchContent dependencies. Other external or configuration-specific dependencies remain fetched as before.

Working with bgfx changes

Example scenario: I need a NativeEngine change accompanied by a bgfx change. I also notice that BabylonJS/bgfx has upstream changes that I want locally. After validating both changes together, I want a BabylonNative PR and a separate bgfx PR.

1. Configure dependency remotes once

git remote add bgfx-upstream https://github.com/BabylonJS/bgfx.git
git remote add bgfx-fork https://github.com/CedricGuillemet/bgfx.git
git fetch bgfx-upstream master

If either remote already exists:

git remote set-url bgfx-upstream https://github.com/BabylonJS/bgfx.git
git remote set-url bgfx-fork https://github.com/CedricGuillemet/bgfx.git

2. Pull bgfx upstream changes into BabylonNative

Start from a clean BabylonNative worktree. This creates a squashed subtree merge commit:

git subtree pull \
  --prefix=Dependencies/bgfx \
  bgfx-upstream master \
  --squash

If local bgfx work already exists, commit it first, run the same pull, and resolve merge conflicts under Dependencies/bgfx normally.

3. Make and validate the coordinated changes

Edit both areas in the same BabylonNative branch:

Plugins/NativeEngine/...
Dependencies/bgfx/...

Commit the coordinated change:

git add Plugins/NativeEngine Dependencies/bgfx
git commit -m "Update NativeEngine and bgfx integration"

4. Push only the bgfx subtree to the bgfx fork

git subtree push synthesizes a branch containing only the history and files under Dependencies/bgfx:

git subtree push \
  --prefix=Dependencies/bgfx \
  bgfx-fork nativeengine-change

Alternatively, split first to inspect the generated branch locally:

git subtree split \
  --prefix=Dependencies/bgfx \
  --branch nativeengine-change

git push -u bgfx-fork nativeengine-change

Open the related bgfx PR:

gh pr create \
  --repo BabylonJS/bgfx \
  --base master \
  --head CedricGuillemet:nativeengine-change \
  --title "Describe the bgfx change" \
  --body "Required by the related BabylonNative change."

The initial import is squashed, so BabylonNative does not contain bgfx's full historical commit graph. Changes made after import can still be split and proposed upstream with this workflow.

5. Open or update the BabylonNative PR

git push -u origin HEAD

gh pr create \
  --repo BabylonJS/BabylonNative \
  --base master \
  --head CedricGuillemet:$(git branch --show-current) \
  --title "Describe the NativeEngine integration" \
  --body "Depends on BabylonJS/bgfx#<PR number>."

Open the bgfx PR first and link it from the BabylonNative PR. If the bgfx PR changes during review, make the corresponding edits under Dependencies/bgfx, commit them on the BabylonNative branch, and run git subtree push again.

After the bgfx PR merges, synchronize the BabylonNative subtree with the merged upstream branch:

git subtree pull \
  --prefix=Dependencies/bgfx \
  bgfx-upstream master \
  --squash

git push origin HEAD

Validation

A clean Win32 MSVC build was configured with QuickJS and D3D11:

cmake -S . -B build\subtree-win32-pr -G Ninja `
  -DNAPI_JAVASCRIPT_ENGINE=QuickJS `
  -DGRAPHICS_API=D3D11 `
  -DCMAKE_BUILD_TYPE=RelWithDebInfo
cmake --build build\subtree-win32-pr --target UnitTests --parallel 4
.\build\subtree-win32-pr\Apps\UnitTests\UnitTests.exe

All 28 native unit tests passed. The clean configure fetched only dependencies that intentionally remain external; none of the subtree-managed repositories were downloaded.

[Copilot]

🔵 Needs a closer look

It introduces a large monorepo/subtree dependency restructure with broad build-system impact, which warrants final human validation despite only minor local issues found.

Pull request overview

This PR converts BabylonNative into a self-contained monorepo by vendoring multiple upstream dependencies under Dependencies/ via squashed git subtree imports, reducing reliance on FetchContent downloads for those components while keeping a few selected dependencies external.

Changes:

• Import several upstream repositories into Dependencies/ using squashed git subtree history.
• Adjust CMake usage in dependency subprojects to avoid re-fetching CMakeExtensions when the helper command is already defined.
• Add/update various supporting files within imported dependencies (e.g., .gitignore, test assets/shaders, helper scripts, docs).

File summaries

File	Description
Apps/HeadlessScreenshotApp/CMakeLists.txt	Removes redundant CMakeExtensions FetchContent usage; relies on top-level CMakeExtensions include.
Dependencies/xr/CMakeLists.txt	Guards CMakeExtensions FetchContent usage based on whether FetchContent_MakeAvailable_With_Message is already available.
Dependencies/UrlLib/.gitignore	Adds ignore for build output in imported UrlLib subtree.
Dependencies/CMakeExtensions/*	Adds vendored CMake helper repository content used across the build.
Dependencies/AndroidExtensions/*	Adds vendored Android helper repository content.
Dependencies/JsRuntimeHost/*	Adds vendored JsRuntimeHost repository content (tests, polyfills, build scripts, docs).
Dependencies/SPIRV-Cross/*	Adds vendored SPIRV-Cross repository content including shaders/reference outputs and helper scripts.
Dependencies/glslang/*	Adds vendored glslang repository content including extensive test corpus and metadata files.
Dependencies/bgfx.cmake/*	Adds vendored bgfx.cmake repository content (CMake integration templates/config).
Dependencies/bgfx/*	Adds vendored bgfx repository content (sources, examples, tools, third-party).
Dependencies/bx/*	Adds vendored bx repository content (compat headers, config files).
Dependencies/bimg/*	Adds vendored bimg repository content (tools, 3rdparty artifacts/config).

Review details

• Files reviewed: 109/12923 changed files
• Comments generated: 1
• Review effort level: Lite

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