Note: This feature is available in Web Workers.
The WebGL2RenderingContext.beginTransformFeedback() method of the WebGL 2 API starts a transform feedback operation.
beginTransformFeedback(primitiveMode)primitiveModeA GLenum specifying the output type of the primitives that will be recorded into the buffer objects that are bound for transform feedback. Possible values:
gl.POINTSgl.LINESgl.TRIANGLESNone (undefined).
const transformFeedback = gl.createTransformFeedback();
gl.bindTransformFeedback(gl.TRANSFORM_FEEDBACK, transformFeedback);
gl.beginTransformFeedback(gl.TRIANGLES);
gl.drawArrays(gl.TRIANGLES, 0, 3);