question: private static void addPointToList ( PointF point , List < PointF > nodes , List < PointF > nodesContact ) { if ( point != null ) { PointF pV = null ; int po1 = 0 , po2 = 0 ; float min1 = INF ; for ( int i = 0 ; i < nodesContact . size ( ) - 1 ; i ++ ) { PointF p1 = nodes . get ( ( int ) nodesContact . get ( i ) . x ) ; PointF p2 = nodes . get ( ( int ) nodesContact . get ( i ) . y ) ; if ( ! MapMath . isObtuseAnglePointAndLine ( point , p1 , p2 ) ) { float minDis = MapMath . getDistanceFromPointToLine ( point , p1 , p2 ) ; if ( min1 > minDis ) { pV = MapMath . getIntersectionCoordinatesFromPointToLine ( point , p1 , p2 ) ; min1 = minDis ; po1 = ( int ) nodesContact . get ( i ) . x ; po2 = ( int ) nodesContact . get ( i ) . y ; } } } nodes . add ( pV ) ; nodesContact . add ( new PointF ( po1 , nodes . size ( ) - 1 ) ) ; nodesContact . add ( new PointF ( po2 , nodes . size ( ) - 1 ) ) ; } }
target:  add point to list