Function getLargestRec 

pub unsafe extern "C" fn getLargestRec(
    match_: c_int,
    ids: *const c_int,
    sx: c_int,
    sz: c_int,
    p0: *mut Pos,
    p1: *mut Pos,
) -> c_int

Find the largest rectangle in ids[sx][sz] which consists only of ‘match’. The limit corners are written to p0 and p1. Returned is the rectangle’s area.