Fix WebGPU renderer memory churn

Author: RenaudRohlinger

src/renderers/common/RenderContexts.js

@@ -53,8 +53,29 @@ class RenderContexts {
 			const format = renderTarget.texture.format;
 			const type = renderTarget.texture.type;
 			const count = renderTarget.textures.length;
-
-			attachmentState = `${ count }:${ format }:${ type }:${ renderTarget.samples }:${ renderTarget.depthBuffer }:${ renderTarget.stencilBuffer }`;
+			const samples = renderTarget.samples;
+			const depthBuffer = renderTarget.depthBuffer;
+			const stencilBuffer = renderTarget.stencilBuffer;
+
+			if ( renderTarget._attachmentState === undefined ||
+				renderTarget._attachmentStateFormat !== format ||
+				renderTarget._attachmentStateType !== type ||
+				renderTarget._attachmentStateSamples !== samples ||
+				renderTarget._attachmentStateCount !== count ||
+				renderTarget._attachmentStateDepth !== depthBuffer ||
+				renderTarget._attachmentStateStencil !== stencilBuffer ) {
+
+				renderTarget._attachmentState = `${ count }:${ format }:${ type }:${ samples }:${ depthBuffer }:${ stencilBuffer }`;
+				renderTarget._attachmentStateFormat = format;
+				renderTarget._attachmentStateType = type;
+				renderTarget._attachmentStateSamples = samples;
+				renderTarget._attachmentStateCount = count;
+				renderTarget._attachmentStateDepth = depthBuffer;
+				renderTarget._attachmentStateStencil = stencilBuffer;
+
+			}
+
+			attachmentState = renderTarget._attachmentState;
 
 		}
 

src/renderers/common/Renderer.js

@@ -594,6 +594,17 @@ class Renderer {
 		 */
 		this.onDeviceLost = this._onDeviceLost;
 
+		/**
+		 * A callback function that defines what should happen when an uncaptured
+		 * backend error is reported (e.g. a WebGPU validation/out-of-memory/internal
+		 * error raised outside an error scope). Applications can override this to
+		 * surface errors in their own UI without letting them escalate to a device
+		 * loss. The default implementation logs to the console.
+		 *
+		 * @type {Function}
+		 */
+		this.onError = this._onError;
+
 		/**
 		 * Defines the type of output buffers. The default `HalfFloatType` is recommend for
 		 * best quality. To save memory and bandwidth, `UnsignedByteType` might be used.
@@ -1196,6 +1207,26 @@ class Renderer {
 
 	}
 
+	/**
+	 * Default implementation of the uncaptured backend error callback.
+	 *
+	 * @private
+	 * @param {Object} info - Information about the uncaptured error.
+	 */
+	_onError( info ) {
+
+		let errorMessage = `THREE.WebGPURenderer: Uncaptured ${ info.api } ${ info.type }`;
+
+		if ( info.message ) {
+
+			errorMessage += `: ${ info.message }`;
+
+		}
+
+		error( errorMessage );
+
+	}
+
 	/**
 	 * Renders the given render bundle.
 	 *