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.
beginQuery(target, query)targetA GLenum specifying the target of the query. Possible values:
gl.ANY_SAMPLES_PASSEDSpecifies 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_CONSERVATIVESame as above, but less accurate and faster version.
gl.TRANSFORM_FEEDBACK_PRIMITIVES_WRITTENNumber of primitives that are written to transform feedback buffers.
queryA WebGLQuery object for which to start the querying.
None (undefined).
const query = gl.createQuery();
gl.beginQuery(gl.ANY_SAMPLES_PASSED, query);
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