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GPUComputePassEncoder

files/en-us/web/api/gpucomputepassencoder/index.md

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{{APIRef("WebGPU API")}}{{SecureContext_Header}}{{AvailableInWorkers}}

The GPUComputePassEncoder interface of the {{domxref("WebGPU API", "WebGPU API", "", "nocode")}} encodes commands related to controlling the compute shader stage, as issued by a {{domxref("GPUComputePipeline")}}. It forms part of the overall encoding activity of a {{domxref("GPUCommandEncoder")}}.

A compute pipeline contains a single compute stage in which a compute shader takes general data, processes it in parallel across a specified number of workgroups, then returns the result in one or more buffers.

A GPUComputePassEncoder object instance is created via the {{domxref("GPUCommandEncoder.beginComputePass()")}} property.

{{InheritanceDiagram}}

Instance properties

  • {{domxref("GPUComputePassEncoder.label", "label")}}
    • : A string providing a label that can be used to identify the object, for example in {{domxref("GPUError")}} messages or console warnings.

Instance methods

  • {{domxref("GPUComputePassEncoder.dispatchWorkgroups", "dispatchWorkgroups()")}}
    • : Dispatches a specific grid of workgroups to perform the work being done by the current {{domxref("GPUComputePipeline")}}.
  • {{domxref("GPUComputePassEncoder.dispatchWorkgroupsIndirect", "dispatchWorkgroupsIndirect()")}}
    • : Dispatches a grid of workgroups, defined by the parameters of a {{domxref("GPUBuffer")}}, to perform the work being done by the current {{domxref("GPUComputePipeline")}}.
  • {{domxref("GPUComputePassEncoder.end", "end()")}}
    • : Completes recording of the current compute pass command sequence.
  • {{domxref("GPUComputePassEncoder.insertDebugMarker", "insertDebugMarker()")}}
    • : Marks a specific point in a series of encoded commands with a label.
  • {{domxref("GPUComputePassEncoder.popDebugGroup", "popDebugGroup()")}}
    • : Ends a debug group, which is begun with a {{domxref("GPUComputePassEncoder.pushDebugGroup", "pushDebugGroup()")}} call.
  • {{domxref("GPUComputePassEncoder.pushDebugGroup", "pushDebugGroup()")}}
    • : Begins a debug group, which is marked with a specified label, and will contain all subsequent encoded commands up until a {{domxref("GPUComputePassEncoder.popDebugGroup", "popDebugGroup()")}} method is invoked.
  • {{domxref("GPUComputePassEncoder.setBindGroup", "setBindGroup()")}}
    • : Sets the {{domxref("GPUBindGroup")}} to use for subsequent compute commands, for a given index.
  • {{domxref("GPUComputePassEncoder.setPipeline", "setPipeline()")}}
    • : Sets the {{domxref("GPUComputePipeline")}} to use for this compute pass.

Examples

In our basic compute demo, several commands are recorded via a {{domxref("GPUCommandEncoder")}}. Most of these commands originate from the GPUComputePassEncoder created via {{domxref("GPUCommandEncoder.beginComputePass()")}}.

js
// …

// Create GPUCommandEncoder to encode commands to issue to the GPU
const commandEncoder = device.createCommandEncoder();

// Create GPUComputePassEncoder to initiate compute pass
const passEncoder = commandEncoder.beginComputePass();

// Issue commands
passEncoder.setPipeline(computePipeline);
passEncoder.setBindGroup(0, bindGroup);
passEncoder.dispatchWorkgroups(Math.ceil(BUFFER_SIZE / 64));

// End the compute pass
passEncoder.end();

// Copy output buffer to staging buffer
commandEncoder.copyBufferToBuffer(
  output,
  0, // Source offset
  stagingBuffer,
  0, // Destination offset
  BUFFER_SIZE,
);

// End frame by passing array of command buffers to command queue for execution
device.queue.submit([commandEncoder.finish()]);

// …

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also