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WebGL2RenderingContext.beginQuery

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The WebGL2RenderingContext.beginQuery() method of the WebGL 2 API starts an asynchronous query. The target parameter indicates which kind of query to begin.

Syntax

void gl.beginQuery(target, query);

Parameters

target

A GLenum specifying the target of the query. Possible values:

gl.ANY_SAMPLES_PASSED: Specifies an occlusion query: these queries detect whether an object is visible (whether the scoped drawing commands pass the depth test and if so, how many samples pass).
gl.ANY_SAMPLES_PASSED_CONSERVATIVE: Same as above above, but less accurate and faster version.
gl.TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN: Number of primitives that are written to transform feedback buffers.

query

A WebGLQuery object for which to start the querying.

Return value

None.

Examples

var query = gl.createQuery();
gl.beginQuery(gl.ANY_SAMPLES_PASSED, query);

// ...

Specifications

Specification	Status	Comment
WebGL 2.0 The definition of 'beginQuery' in that specification.	Editor's Draft	Initial definition.
OpenGL ES 3.0 The definition of 'glBeginQuery' in that specification.	Standard	Man page of the (similar) OpenGL API.

Browser compatibilityUpdate compatibility data on GitHub

	Desktop
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic support	56	No	51	No	43	No

	Mobile
	Android webview	Chrome for Android	Edge Mobile	Firefox for Android	Opera for Android	iOS Safari	Samsung Internet
Basic support	58	58	No	51	43	No	7.0