Function ncvisual_blit 

pub unsafe extern "C" fn ncvisual_blit(
    nc: *mut notcurses,
    ncv: *mut ncvisual,
    vopts: *const ncvisual_options,
) -> *mut ncplane

Render the decoded frame according to the provided options (which may be NULL). The plane used for rendering depends on vopts->n and vopts->flags. If NCVISUAL_OPTION_CHILDPLANE is set, vopts->n must not be NULL, and the plane will always be created as a child of vopts->n. If this flag is not set, and vopts->n is NULL, a new plane is created as root of a new pile. If the flag is not set and vopts->n is not NULL, we render to vopts->n. A subregion of the visual can be rendered using ‘begx’, ‘begy’, ‘lenx’, and ‘leny’. Negative values for any of these are an error. It is an error to specify any region beyond the boundaries of the frame. Returns the (possibly newly-created) plane to which we drew. Pixels may not be blitted to the standard plane.