This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
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
GLenumspecifying 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
WebGLQueryobject 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.
| Feature | Chrome | Firefox | Edge | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic Support | 56 | 51.0 | (No) | (No) | 43 | (No) |
| Feature | Android | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
|---|---|---|---|---|---|---|---|
| Basic Support | (No) | (No) | (No) | (No) | (No) | (No) | (No) |