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GPUQuerySet

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

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

The GPUQuerySet interface of the {{domxref("WebGPU API", "WebGPU API", "", "nocode")}} is used to record the results of queries on passes, such as occlusion or timestamp queries.

  • Occlusion queries are available on render passes to query whether any fragment samples pass all the per-fragment tests for a set of drawing commands (including scissor, sample mask, alpha to coverage, stencil, and depth tests). To run an occlusion query, an appropriate GPUQuerySet must be provided as the value of the occlusionQuerySet descriptor property when invoking {{domxref("GPUCommandEncoder.beginRenderPass()")}} to run a render pass.

  • Timestamp queries allow applications to write timestamps to a GPUQuerySet. To run a timestamp query, appropriate GPUQuerySets must be provided inside the value of the timestampWrites descriptor property when invoking {{domxref("GPUCommandEncoder.beginRenderPass()")}} to run a render pass, or {{domxref("GPUCommandEncoder.beginComputePass()")}} to run a compute pass.

[!NOTE] The timestamp-query feature needs to be enabled to use timestamp queries.

A GPUQuerySet object instance is created using the {{domxref("GPUDevice.createQuerySet()")}} method.

{{InheritanceDiagram}}

Instance properties

  • {{domxref("GPUQuerySet.count", "count")}} {{ReadOnlyInline}}
    • : A number specifying the number of queries managed by the GPUQuerySet.
  • {{domxref("GPUQuerySet.label", "label")}}
    • : A string providing a label that can be used to identify the object, for example in {{domxref("GPUError")}} messages or console warnings.
  • {{domxref("GPUQuerySet.type", "type")}} {{ReadOnlyInline}}
    • : An enumerated value specifying the type of queries managed by the GPUQuerySet.

Instance methods

  • {{domxref("GPUQuerySet.destroy", "destroy()")}}
    • : Destroys the GPUQuerySet.

Examples

The following snippet creates a GPUQuerySet that holds 32 occlusion query results, and then returns the type and count:

js
const querySet = device.createQuerySet({
  type: "occlusion",
  count: 32,
});

console.log(querySet.count); // 32
console.log(querySet.type); // "occlusion"

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also