GPUComputePassEncoder

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is available in Web Workers.

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

Instance properties

label: A string providing a label that can be used to identify the object, for example in GPUError messages or console warnings.

Instance methods

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

Examples

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

// …

// 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()]);

// …