[Native] Report engine.name "Native" and implement updateTextureData

The native engine inherited engine.name === "WebGL" from ThinEngine, so code
that guards WebGL-only _gl access with �ngine.name === "WebGL" ran on the
native engine and dereferenced the null _gl context (e.g. TEXTURE_2D undefined).
updateTextureData also threw "not implemented".

- Report a distinct engine name ("Native"), mirroring how the WebGPU engine
  reports "WebGPU", so name-gated WebGL-only code paths skip the native engine.
- Implement updateTextureData: forward the sub-rectangle (plus invertY, so the
  native side can match the base texture's vertical orientation) to the native
  engine. generateMipMaps is ignored (mip regeneration after a partial update is
  not supported on Native).

Pairs with the BabylonNative change adding NativeEngine::UpdateTextureData.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 2 people

packages/dev/core/src/Engines/Native/nativeInterfaces.ts

@@ -64,6 +64,17 @@ export interface INativeEngine {
     initializeTexture(texture: NativeTexture, width: number, height: number, hasMips: boolean, format: number, renderTarget: boolean, srgb: boolean, samples: number): void;
     loadTexture(texture: NativeTexture, data: ArrayBufferView, generateMips: boolean, invertY: boolean, srgb: boolean, onSuccess: () => void, onError: () => void): void;
     loadRawTexture(texture: NativeTexture, data: ArrayBufferView, width: number, height: number, format: number, generateMips: boolean, invertY: boolean): void;
+    updateTextureData(
+        texture: NativeTexture,
+        data: ArrayBufferView,
+        xOffset: number,
+        yOffset: number,
+        width: number,
+        height: number,
+        faceIndex: number,
+        lod: number,
+        invertY: boolean
+    ): void;
     loadRawTexture2DArray(
         texture: NativeTexture,
         data: Nullable<ArrayBufferView>,

packages/dev/core/src/Engines/thinNativeEngine.pure.ts

@@ -305,6 +305,10 @@ export class ThinNativeEngine extends ThinEngine {
         this._webGLVersion = 2;
         this.disableUniformBuffers = true;
         this._shaderPlatformName = "NATIVE";
+        // Babylon Native is not WebGL and has no _gl context. Report a distinct engine name (like
+        // WebGPU reports "WebGPU") so application/feature code that branches on engine.name === "WebGL"
+        // to touch the WebGL-only _gl context skips the native engine instead of dereferencing null.
+        this._name = "Native";
 
         // TODO: Initialize this more correctly based on the hardware capabilities.
         // Init caps
@@ -2662,7 +2666,15 @@ export class ThinNativeEngine extends ThinEngine {
         lod: number = 0,
         generateMipMaps = false
     ): void {
-        throw new Error("updateTextureData not implemented.");
+        if (!texture._hardwareTexture) {
+            return;
+        }
+
+        // bgfx updates the requested sub-rectangle of the existing texture (faceIndex selects the cube
+        // face / array layer, lod selects the mip level). invertY is forwarded so the native side can match
+        // the vertical orientation the base texture upload uses. Mip regeneration after a partial update is
+        // not supported on Native, so generateMipMaps is ignored (consistent with the other raw-texture paths).
+        this._engine.updateTextureData(texture._hardwareTexture.underlyingResource, imageData, xOffset, yOffset, width, height, faceIndex, lod, texture.invertY);
     }
 
     /**