Function libeyelink_sys::eyelink_request_image

pub unsafe extern "C" fn eyelink_request_image(
    type_: INT16, 
    xsize: INT16, 
    ysize: INT16
) -> INT16

@internal

Request an image of \c <type> with size less than or eqaul to \c <xsize> and \c <ysize>.

@return \c 0 if sent OK, else send error code.