org.locationtech.jts.noding.snap

Class SnappingNoder

java.lang.Object

org.locationtech.jts.noding.snap.SnappingNoder

All Implemented Interfaces:

Noder

public class SnappingNoder
extends Object
implements Noder

Nodes a set of segment strings snapping vertices and intersection points together if they lie within the given snap tolerance distance. Vertices take priority over intersection points for snapping. Input segment strings are generally only split at true node points (i.e. the output segment strings are of maximal length in the output arrangement).

The snap tolerance should be chosen to be as small as possible while still producing a correct result. It probably only needs to be small enough to eliminate "nearly-coincident" segments, for which intersection points cannot be computed accurately. This implies a factor of about 10e-12 smaller than the magnitude of the segment coordinates.

With an appropriate snap tolerance this algorithm appears to be very robust. So far no failure cases have been found, given a small enough snap tolerance.

The correctness of the output is not verified by this noder. If required this can be done by ValidatingNoder.

Version:

1.17

Constructor Summary

Constructors

Constructor and Description
SnappingNoder(double snapTolerance) Creates a snapping noder using the given snap distance tolerance.

Method Summary

Modifier and Type	Method and Description
void	computeNodes(Collection inputSegStrings) Computes the noding for a collection of SegmentStrings.
Collection	getNodedSubstrings() Returns a Collection of fully noded SegmentStrings.

Methods inherited from class java.lang.Object

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

Constructor Detail

SnappingNoder

public SnappingNoder(double snapTolerance)

Creates a snapping noder using the given snap distance tolerance.

Parameters:

snapTolerance - points are snapped if within this distance

Method Detail

getNodedSubstrings

public Collection getNodedSubstrings()

Description copied from interface: Noder

Returns a Collection of fully noded SegmentStrings. The SegmentStrings have the same context as their parent.

Specified by:

getNodedSubstrings in interface Noder

Returns:

a Collection of NodedSegmentStrings representing the substrings

computeNodes

public void computeNodes(Collection inputSegStrings)

Description copied from interface: Noder

Computes the noding for a collection of SegmentStrings. Some Noders may add all these nodes to the input SegmentStrings; others may only add some or none at all.

Specified by:

computeNodes in interface Noder

Parameters:

inputSegStrings - a Collection of SegmentStrings