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 compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic supportChrome Full support 56Edge No support NoFirefox Full support 51IE No support NoOpera Full support 43Safari No support NoWebView Android Full support 58Chrome Android Full support 58Edge Mobile No support NoFirefox Android Full support 51Opera Android Full support 43Safari iOS No support NoSamsung Internet Android Full support 7.0

Legend

Full support  
Full support
No support  
No support

See also

Document Tags and Contributors

Contributors to this page: fscholz, teoli
Last updated by: fscholz,