Auto-populate is2DArray/depth in wrapNativeTexture from native layer count (#18535)

Author: bghgary

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

@@ -78,6 +78,7 @@ export interface INativeEngine {
     loadCubeTextureWithMips(texture: NativeTexture, data: Array<Array<ArrayBufferView>>, invertY: boolean, srgb: boolean, onSuccess: () => void, onError: () => void): void;
     getTextureWidth(texture: NativeTexture): number;
     getTextureHeight(texture: NativeTexture): number;
+    getTextureLayerCount?(texture: NativeTexture): number;
     deleteTexture(texture: NativeTexture): void;
     readTexture(
         texture: NativeTexture,

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

@@ -2035,6 +2035,13 @@ export class ThinNativeEngine extends ThinEngine {
         internalTexture.baseHeight = this._engine.getTextureHeight(texture);
         internalTexture.width = internalTexture.baseWidth;
         internalTexture.height = internalTexture.baseHeight;
+        if (this._engine.getTextureLayerCount) {
+            const layerCount = this._engine.getTextureLayerCount(texture);
+            if (layerCount > 1) {
+                internalTexture.is2DArray = true;
+                internalTexture.baseDepth = internalTexture.depth = layerCount;
+            }
+        }
         internalTexture.isReady = true;
         internalTexture.useMipMaps = hasMipMaps;
         this.updateTextureSamplingMode(samplingMode, internalTexture);
@@ -2073,6 +2080,13 @@ export class ThinNativeEngine extends ThinEngine {
                 `updateWrappedNativeTexture: new handle dimensions (${newWidth}x${newHeight}) must match the wrapped texture's dimensions (${internalTexture.baseWidth}x${internalTexture.baseHeight}).`
             );
         }
+        if (this._engine.getTextureLayerCount) {
+            const newLayerCount = this._engine.getTextureLayerCount(texture);
+            const oldLayerCount = internalTexture.is2DArray ? internalTexture.depth : 1;
+            if (newLayerCount !== oldLayerCount) {
+                throw new Error(`updateWrappedNativeTexture: new handle layer count (${newLayerCount}) must match the wrapped texture's layer count (${oldLayerCount}).`);
+            }
+        }
 
         // Pre-validate before mutating any state so a thrown precondition leaves the InternalTexture untouched.
         // Note: rtWrapper.texture only returns _textures[0]; walk every attachment to catch the multi-RT case where