question: public static final List < Geo > polyNearPoly ( GeoArray s , GeoArray r , double near ) { int rlen = r . getSize ( ) ; int slen = s . getSize ( ) ; Geo pl0 = r . get ( rlen - 1 ) ; Geo pl1 = new Geo ( ) ; Geo sl0 = s . get ( slen - 1 ) ; Geo sl1 = new Geo ( ) ; List < Geo > list = null ; for ( int j = 0 ; j < rlen ; j ++ ) { pl1 = r . get ( j , pl1 ) ; for ( int i = 0 ; i < slen ; i ++ ) { sl1 = s . get ( i , sl1 ) ; Geo ret = segmentsIntersectOrNear ( sl0 , sl1 , pl0 , pl1 , near ) ; if ( ret != null ) { if ( list == null ) { list = new LinkedList < Geo > ( ) ; } list . add ( ret ) ; } sl0 = sl1 ; } pl0 = pl1 ; } return list ; }
target:  Is one region's boundary within 'near' range of a region? Note: good practice is s describes a smaller area than r.