WebGPURenderer: Prevent dispose of default textures. (#31860)

* WebGPURenderer: Prevent dispose of default textures.

* WebGLTextureUtils: Remove flag.

src/renderers/common/Backend.js

@@ -328,8 +328,9 @@ class Backend {
 	 *
 	 * @abstract
 	 * @param {Texture} texture - The texture.
+	 * @param {boolean} [isDefaultTexture=false] - Whether the texture uses a default GPU texture or not.
 	 */
-	destroyTexture( /*texture*/ ) { }
+	destroyTexture( /*texture, isDefaultTexture*/ ) { }
 
 	/**
 	 * Returns texture data as a typed array.

src/renderers/common/Textures.js

@@ -475,8 +475,15 @@ class Textures extends DataMap {
 
 		if ( this.has( texture ) === true ) {
 
+			// if a texture is not ready for use, it falls back to a default texture so it's possible
+			// to use it for rendering. If a texture in this state is disposed, it's important to
+			// not destroy/delete the underlying GPU texture object since it is cached and shared with
+			// other textures.
+
+			const isDefaultTexture = this.get( texture ).isDefaultTexture;
+
 			this.backend.destroySampler( texture );
-			this.backend.destroyTexture( texture );
+			this.backend.destroyTexture( texture, isDefaultTexture );
 
 			this.delete( texture );
 

src/renderers/webgl-fallback/WebGLBackend.js

@@ -1302,10 +1302,11 @@ class WebGLBackend extends Backend {
 	 * Destroys the GPU data for the given texture object.
 	 *
 	 * @param {Texture} texture - The texture.
+	 * @param {boolean} [isDefaultTexture=false] - Whether the texture uses a default GPU texture or not.
 	 */
-	destroyTexture( texture ) {
+	destroyTexture( texture, isDefaultTexture = false ) {
 
-		this.textureUtils.destroyTexture( texture );
+		this.textureUtils.destroyTexture( texture, isDefaultTexture );
 
 	}
 

src/renderers/webgl-fallback/utils/WebGLTextureUtils.js

@@ -409,8 +409,7 @@ class WebGLTextureUtils {
 
 		backend.set( texture, {
 			textureGPU,
-			glTextureType,
-			isDefault: true
+			glTextureType
 		} );
 
 	}
@@ -741,14 +740,20 @@ class WebGLTextureUtils {
 	 * Destroys the GPU data for the given texture object.
 	 *
 	 * @param {Texture} texture - The texture.
+	 * @param {boolean} [isDefaultTexture=false] - Whether the texture uses a default GPU texture or not.
 	 */
-	destroyTexture( texture ) {
+	destroyTexture( texture, isDefaultTexture = false ) {
 
 		const { gl, backend } = this;
 		const { textureGPU, renderTarget } = backend.get( texture );
 
 		this.deallocateRenderBuffers( renderTarget );
-		gl.deleteTexture( textureGPU );
+
+		if ( isDefaultTexture === false ) {
+
+			gl.deleteTexture( textureGPU );
+
+		}
 
 		backend.delete( texture );
 

src/renderers/webgpu/WebGPUBackend.js

@@ -1906,10 +1906,11 @@ class WebGPUBackend extends Backend {
 	 * Destroys the GPU data for the given texture object.
 	 *
 	 * @param {Texture} texture - The texture.
+	 * @param {boolean} [isDefaultTexture=false] - Whether the texture uses a default GPU texture or not.
 	 */
-	destroyTexture( texture ) {
+	destroyTexture( texture, isDefaultTexture = false ) {
 
-		this.textureUtils.destroyTexture( texture );
+		this.textureUtils.destroyTexture( texture, isDefaultTexture );
 
 	}
 

src/renderers/webgpu/utils/WebGPUTextureUtils.js

@@ -293,13 +293,14 @@ class WebGPUTextureUtils {
 	 * Destroys the GPU data for the given texture object.
 	 *
 	 * @param {Texture} texture - The texture.
+	 * @param {boolean} [isDefaultTexture=false] - Whether the texture uses a default GPU texture or not.
 	 */
-	destroyTexture( texture ) {
+	destroyTexture( texture, isDefaultTexture = false ) {
 
 		const backend = this.backend;
 		const textureData = backend.get( texture );
 
-		if ( textureData.texture !== undefined ) textureData.texture.destroy();
+		if ( textureData.texture !== undefined && isDefaultTexture === false ) textureData.texture.destroy();
 
 		if ( textureData.msaaTexture !== undefined ) textureData.msaaTexture.destroy();