Function polylabel::polylabel_ffi

#[no_mangle]
pub extern "C" fn polylabel_ffi(
    outer: Array, 
    inners: WrapperArray, 
    tolerance: c_double
) -> Position

FFI access to the polylabel function

Accepts three arguments:

• an exterior ring Array
• zero or more interior rings WrapperArray
• a tolerance c_double.