WebGL2RenderingContext: beginQuery() method

{{APIRef("WebGL")}}{{AvailableInWorkers}}

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

Syntax

beginQuery(target, query)

Parameters

• target

  • : A {{domxref("WebGL_API/Types", "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 {{domxref("WebGLQuery")}} object for which to start the querying.

Return value

None ({{jsxref("undefined")}}).

Examples

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

// …

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("WebGLQuery")}}