Package org.tinfour.utils

Class PolylineThinner

java.lang.Object

org.tinfour.utils.PolylineThinner

public class PolylineThinner
extends Object

Provides utilities for reducing the number of points in a polygon or line feature by using Visvalingam's algorithm.

Constructor Summary

Constructors

Constructor	Description
PolylineThinner()	Standard constructor.

Method Summary

Modifier and Type	Method	Description
IPolyline	thinPoints(IPolyline feature, List<IPolyline> neighborList, double threshold)	Given a feature, apply Visvalingam's algorithm to reduce the complexity of the feature geometry.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PolylineThinner

public PolylineThinner()

Standard constructor.

Method Detail

thinPoints

public IPolyline thinPoints(IPolyline feature,
                            List<IPolyline> neighborList,
                            double threshold)

Given a feature, apply Visvalingam's algorithm to reduce the complexity of the feature geometry. Features are compared against their neighbors to ensure that reductions in line complexity do not introduce intersections of line segments to the collection.

Parameters:

feature - the feature to be reduced

neighborList - a potentially empty list of neighboring features (null values are allowed); this list is allowed to include the input feature itself.

threshold - the value to be used for the Visvalingham area criterion.

Returns:

if points were removed from the feature, a new instance reflecting the changed geometry; if the feature was unchanged, a null.