question: private static Position [ ] simplifyDouglasPeucker ( Position [ ] points , double sqTolerance ) { int last = points . length - 1 ; ArrayList < Position > simplified = new ArrayList < > ( ) ; simplified . add ( points [ 0 ] ) ; simplified . addAll ( simplifyDpStep ( points , 0 , last , sqTolerance , simplified ) ) ; simplified . add ( points [ last ] ) ; return simplified . toArray ( new Position [ simplified . size ( ) ] ) ; }
target:  Simplification using Ramer-Douglas-Peucker algorithm