Add BABYLON_NATIVE_PLUGIN_NATIVEENGINE_LOAD_IMAGES CMake option

[CedricGuillemet]

Summary

Adds a new CMake option BABYLON_NATIVE_PLUGIN_NATIVEENGINE_LOAD_IMAGES (default ON) that enables all bimg / bx / stb / WebP image-decoding code from the NativeEngine plugin. Useful for embedders that decode textures themselves and want to reduce binary size.

What it does when OFF

• bimg, bimg_encode, bimg_decode are no longer linked into NativeEngine.
• BABYLON_NATIVE_PLUGIN_NATIVEENGINE_WEBP is forced OFF (libwebp is not fetched/built).
• All <bimg/...>, <bx/...>, <stb/...>, <webp/...> includes are guarded out.
• All bimg-using helpers (Cast, TransformImage, GetPixelMapper, ReorientImage, ParseImage, PrepareImage, LoadTextureFromImage, LoadCubeTextureFromImages, related static_asserts) are excluded from compilation.
• The following NativeEngine instance methods stay registered but throw a Napi::Error ("Image loading is disabled in this build (BABYLON_NATIVE_DISABLE_IMAGE_LOADING).") when invoked:
  • loadTexture
  • loadRawTexture
  • loadRawTexture2DArray
  • loadCubeTexture
  • loadCubeTextureWithMips
  • createImageBitmap
  • resizeImageBitmap
• ReadTexture's bimg-based format-conversion path also throws; raw readback when source/target formats match continues to work.
• FlipImage is kept available because it's also used by ReadTexture.

Binary size impact

Measured on Windows x64 Release Playground.exe (MSVC, default options):

Build	Playground.exe
Image loading ON (default)	3,610,112 bytes
Image loading OFF	3,152,384 bytes
Saved	457,728 bytes (~447 KiB, ~12.7%)

How to use

cmake -B buildNoImage -A x64 -BABYLON_NATIVE_PLUGIN_NATIVEENGINE_LOAD_IMAGES=OFF
cmake --build buildNoImage --target Playground --config Release

[Copilot]

Pull request overview

Adds an opt-in CMake build flag to compile the NativeEngine plugin without image decoding support (bimg/stb/WebP code paths), reducing binary size for embedders that handle texture decoding externally.

Changes:

• Introduces BABYLON_NATIVE_DISABLE_IMAGE_LOADING top-level CMake option (default OFF) and forces BABYLON_NATIVE_PLUGIN_NATIVEENGINE_WEBP=OFF when enabled.
• Guards bimg/stb/WebP includes and helper implementations in NativeEngine and makes image-loading-related NAPI entrypoints throw when invoked in a disabled build.
• Stops explicitly linking bimg* into NativeEngine when the option is enabled.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
Plugins/NativeEngine/Source/NativeEngine.h	Guards bimg/bx includes behind BABYLON_NATIVE_DISABLE_IMAGE_LOADING.
Plugins/NativeEngine/Source/NativeEngine.cpp	Guards image-loading implementation; keeps APIs but throws when disabled; disables format conversion path when disabled.
Plugins/NativeEngine/CMakeLists.txt	Conditionally links bimg* and adds the compile definition when image loading is disabled.
CMakeLists.txt	Adds the new option and forces WebP support off when image loading is disabled.