Function gvr_sys::gvr_buffer_viewport_get_external_surface_id

pub unsafe extern "C" fn gvr_buffer_viewport_get_external_surface_id(
    viewport: *const gvr_buffer_viewport
) -> i32

Gets the ID of the externally-managed Surface texture from which this viewport reads undistored pixels.

@param viewport The buffer viewport. @return ID of the externally-managed Surface of undistorted pixels.