org.locationtech.jts.simplify

Class TaggedLineStringSimplifier

java.lang.Object

org.locationtech.jts.simplify.TaggedLineStringSimplifier

public class TaggedLineStringSimplifier
extends java.lang.Object

Simplifies a TaggedLineString, preserving topology (in the sense that no new intersections are introduced). Uses the recursive Douglas-Peucker algorithm.

Version:

1.7

Field Summary

Fields

Modifier and Type	Field and Description
private double	distanceTolerance
private LineSegmentIndex	inputIndex
private LineIntersector	li
private TaggedLineString	line
private Coordinate[]	linePts
private LineSegmentIndex	outputIndex

Constructor Summary

Constructors

Constructor and Description
TaggedLineStringSimplifier(LineSegmentIndex inputIndex, LineSegmentIndex outputIndex)

Method Summary

Modifier and Type	Method and Description
private int	findFurthestPoint(Coordinate[] pts, int i, int j, double[] maxDistance)
private LineSegment	flatten(int start, int end) Flattens a section of the line between indexes start and end, replacing them with a line between the endpoints.
private boolean	hasBadInputIntersection(TaggedLineString parentLine, int[] sectionIndex, LineSegment candidateSeg)
private boolean	hasBadIntersection(TaggedLineString parentLine, int[] sectionIndex, LineSegment candidateSeg)
private boolean	hasBadOutputIntersection(LineSegment candidateSeg)
private boolean	hasInteriorIntersection(LineSegment seg0, LineSegment seg1)
private static boolean	isInLineSection(TaggedLineString line, int[] sectionIndex, TaggedLineSegment seg) Tests whether a segment is in a section of a TaggedLineString
private void	remove(TaggedLineString line, int start, int end) Remove the segs in the section of the line
void	setDistanceTolerance(double distanceTolerance) Sets the distance tolerance for the simplification.
(package private) void	simplify(TaggedLineString line) Simplifies the given TaggedLineString using the distance tolerance specified.
private void	simplifySection(int i, int j, int depth)

Methods inherited from class java.lang.Object

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

Field Detail

li

private LineIntersector li

inputIndex

private LineSegmentIndex inputIndex

outputIndex

private LineSegmentIndex outputIndex

line

private TaggedLineString line

linePts

private Coordinate[] linePts

distanceTolerance

private double distanceTolerance

Constructor Detail

TaggedLineStringSimplifier

public TaggedLineStringSimplifier(LineSegmentIndex inputIndex,
                                  LineSegmentIndex outputIndex)

Method Detail

setDistanceTolerance

public void setDistanceTolerance(double distanceTolerance)

Sets the distance tolerance for the simplification. All vertices in the simplified geometry will be within this distance of the original geometry.

Parameters:

distanceTolerance - the approximation tolerance to use

simplify

void simplify(TaggedLineString line)

Simplifies the given TaggedLineString using the distance tolerance specified.

Parameters:

line - the linestring to simplify

simplifySection

private void simplifySection(int i,
                             int j,
                             int depth)

findFurthestPoint

private int findFurthestPoint(Coordinate[] pts,
                              int i,
                              int j,
                              double[] maxDistance)

flatten

private LineSegment flatten(int start,
                            int end)

Flattens a section of the line between indexes start and end, replacing them with a line between the endpoints. The input and output indexes are updated to reflect this.

Parameters:

start - the start index of the flattened section

end - the end index of the flattened section

Returns:

the new segment created

hasBadIntersection

private boolean hasBadIntersection(TaggedLineString parentLine,
                                   int[] sectionIndex,
                                   LineSegment candidateSeg)

hasBadOutputIntersection

private boolean hasBadOutputIntersection(LineSegment candidateSeg)

hasBadInputIntersection

private boolean hasBadInputIntersection(TaggedLineString parentLine,
                                        int[] sectionIndex,
                                        LineSegment candidateSeg)

isInLineSection

private static boolean isInLineSection(TaggedLineString line,
                                       int[] sectionIndex,
                                       TaggedLineSegment seg)

Tests whether a segment is in a section of a TaggedLineString

Parameters:

line -

sectionIndex -

seg -

Returns:

hasInteriorIntersection

private boolean hasInteriorIntersection(LineSegment seg0,
                                        LineSegment seg1)

remove

private void remove(TaggedLineString line,
                    int start,
                    int end)

Remove the segs in the section of the line

Parameters:

line -

pts -

sectionStartIndex -

sectionEndIndex -