Note: This feature is available in Web Workers.
The WebGL2RenderingContext.getTransformFeedbackVarying() method of the WebGL 2 API returns information about varying variables from WebGLTransformFeedback buffers.
getTransformFeedbackVarying(program, index)programA WebGLProgram.
indexA GLuint specifying the index of the varying variable whose information to retrieve.
A WebGLActiveInfo object.
activeInfo = gl.getTransformFeedbackVarying(program, 0);