WebGL2RenderingContext.beginQuery() - Web APIs 编辑

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

Browser compatibility

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See also

• WebGLQuery