WebGPURenderer: Introduce dispatchWorkgroupsIndirect (#31488)

* introduce dispatchWorkgroupsIndirect

* update: dispatchSizeOrCount to dispatchSize

* update: dispatchSizeOrCount to dispatchSize

* update: dispatchSizeOrCount to dispatchSize

---------

Co-authored-by: Attila Schroeder <attila-schroeder.79@gmail.com>

src/renderers/common/Renderer.js

@@ -2420,10 +2420,13 @@ class Renderer {
 	 * if the renderer has been initialized.
 	 *
 	 * @param {Node|Array<Node>} computeNodes - The compute node(s).
-	 * @param {?(Array<number>|number)} [dispatchSizeOrCount=null] - Array with [ x, y, z ] values for dispatch or a single number for the count.
+	 * @param {number|Array<number>|GPUBuffer} [dispatchSize=null]
+	 * - A single number representing count, or
+	 * - An array [x, y, z] representing dispatch size, or
+	 * - A GPUBuffer for indirect dispatch size.
 	 * @return {Promise|undefined} A Promise that resolve when the compute has finished. Only returned when the renderer has not been initialized.
 	 */
-	compute( computeNodes, dispatchSizeOrCount = null ) {
+	compute( computeNodes, dispatchSize = null ) {
 
 		if ( this._isDeviceLost === true ) return;
 
@@ -2508,7 +2511,7 @@ class Renderer {
 			const computeBindings = bindings.getForCompute( computeNode );
 			const computePipeline = pipelines.getForCompute( computeNode, computeBindings );
 
-			backend.compute( computeNodes, computeNode, computeBindings, computePipeline, dispatchSizeOrCount );
+			backend.compute( computeNodes, computeNode, computeBindings, computePipeline, dispatchSize );
 
 		}
 
@@ -2529,16 +2532,17 @@ class Renderer {
 	 *
 	 * @async
 	 * @param {Node|Array<Node>} computeNodes - The compute node(s).
-	 * @param {?(Array<number>|number)} [dispatchSizeOrCount=null] - Array with [ x, y, z ] values for dispatch or a single number for the count.
+	 * @param {number|Array<number>|GPUBuffer} [dispatchSize=null]
+	 * - A single number representing count, or
+	 * - An array [x, y, z] representing dispatch size, or
+	 * - A GPUBuffer for indirect dispatch size.
 	 * @return {Promise} A Promise that resolve when the compute has finished.
 	 */
-	async computeAsync( computeNodes, dispatchSizeOrCount = null ) {
+	async computeAsync( computeNodes, dispatchSize = null ) {
 
-		warnOnce( 'Renderer: "computeAsync()" has been deprecated. Use "compute()" and "await renderer.init();" when creating the renderer.' ); // @deprecated r181
-
-		await this.init();
+		if ( this._initialized === false ) await this.init();
 
-		this.compute( computeNodes, dispatchSizeOrCount );
+		this.compute( computeNodes, dispatchSize );
 
 	}
 

src/renderers/webgpu/WebGPUBackend.js

@@ -1343,9 +1343,12 @@ class WebGPUBackend extends Backend {
 	 * @param {Node} computeNode - The compute node.
 	 * @param {Array<BindGroup>} bindings - The bindings.
 	 * @param {ComputePipeline} pipeline - The compute pipeline.
-	 * @param {?(Array<number>|number)} [dispatchSizeOrCount=null] - Array with [ x, y, z ] values for dispatch or a single number for the count.
+	 * @param {number|Array<number>|GPUBuffer} [dispatchSize=null]
+	 * - A single number representing count, or
+	 * - An array [x, y, z] representing dispatch size, or
+	 * - A GPUBuffer for indirect dispatch size.
 	 */
-	compute( computeGroup, computeNode, bindings, pipeline, dispatchSizeOrCount = null ) {
+	compute( computeGroup, computeNode, bindings, pipeline, dispatchSize = null ) {
 
 		const computeNodeData = this.get( computeNode );
 		const { passEncoderGPU } = this.get( computeGroup );
@@ -1367,19 +1370,29 @@ class WebGPUBackend extends Backend {
 
 		}
 
-		let dispatchSize;
+		if ( dispatchSize === null ) {
 
-		if ( dispatchSizeOrCount === null ) {
+			dispatchSize = computeNode.count;
 
-			dispatchSizeOrCount = computeNode.count;
+		}
+
+		// When the dispatchSize is set with a StorageBuffer from the GPU.
+
+		if ( dispatchSize && typeof dispatchSize === 'object' && dispatchSize.isIndirectStorageBufferAttribute ) {
+
+			const dispatchBuffer = this.get( dispatchSize ).buffer;
+
+			passEncoderGPU.dispatchWorkgroupsIndirect( dispatchBuffer, 0 );
+
+			return;
 
 		}
 
-		if ( typeof dispatchSizeOrCount === 'number' ) {
+		if ( typeof dispatchSize === 'number' ) {
 
 			// If a single number is given, we calculate the dispatch size based on the workgroup size
 
-			const count = dispatchSizeOrCount;
+			const count = dispatchSize;
 
 			if ( computeNodeData.dispatchSize === undefined || computeNodeData.count !== count ) {
 
@@ -1416,10 +1429,6 @@ class WebGPUBackend extends Backend {
 
 			dispatchSize = computeNodeData.dispatchSize;
 
-		} else {
-
-			dispatchSize = dispatchSizeOrCount;
-
 		}
 
 		//