Function FlattenWrappedPhase 

pub unsafe extern "C" fn FlattenWrappedPhase(
    wrappedphase: *mut *mut f32,
    unwrappedest: *mut *mut f32,
    nrow: c_long,
    ncol: c_long,
) -> c_int

Given a wrapped phase array and an unwrapped phase array, subtracts the unwrapped data elementwise from the wrapped data and stores the result, rewrapped to [0,2pi), in the wrapped array.