WebGL2RenderingContext: beginQuery() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2021.

Note: This feature is available in Web Workers.

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

Syntax

js
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, 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 (undefined).

Examples

js
const query = gl.createQuery();
gl.beginQuery(gl.ANY_SAMPLES_PASSED, query);

// …

Specifications

Specification
WebGL 2.0 Specification
# 3.7.12

Browser compatibility

BCD tables only load in the browser

See also