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
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
beginQuery | Chrome Full support 56 | Edge Full support 79 | Firefox Full support 51 | IE No support No | Opera Full support 43 | Safari No support No | WebView Android Full support 58 | Chrome Android Full support 58 | Firefox Android Full support 51 | Opera Android Full support 43 | Safari iOS No support No | Samsung Internet Android Full support 7.0 |
Legend
- Full support
- Full support
- No support
- No support