com.revolsys.jts.geom.segment

Class AbstractLineSegment

java.lang.Object

com.revolsys.jts.geom.impl.AbstractGeometry

com.revolsys.jts.geom.impl.AbstractLineString

com.revolsys.jts.geom.segment.AbstractLineSegment

All Implemented Interfaces:

DataTypeProxy, Geometry, Lineal, LineString, LineSegment, Serializable, Cloneable, Comparable<Object>

Direct Known Subclasses:

AbstractSegment, LineSegmentDouble

public abstract class AbstractLineSegment
extends AbstractLineString
implements LineSegment

See Also:

Serialized Form

Field Summary

Fields inherited from interface com.revolsys.jts.geom.Geometry

M, sortedGeometryTypes, X, Y, Z

Constructor Summary

Constructors

Constructor and Description
AbstractLineSegment()

Method Summary

Methods

Modifier and Type	Method and Description
double	angle() Computes the angle that the vector defined by this segment makes with the X-axis.
AbstractLineSegment	clone() Creates and returns a full copy of this LineString object.
Point	closestPoint(Point point) Computes the closest point on this line segment to another point.
Point[]	closestPoints(LineSegment line) Computes the closest points on two line segments.
protected int	compareTo(int index, LineSegment other)
int	compareTo(Object other) Compares this object with the specified object for order.
<V extends Geometry> V	convert(GeometryFactory geometryFactory) Convert the geometry to the requried geometry factory.
protected LineSegment	createLineSegment(GeometryFactory geometryFactory, int axisCount, double... coordinates)
protected Point	createPoint(GeometryFactory geometryFactory, double... coordinates)
double	distance(double x, double y)
double	distance(LineSegment line) Computes the distance between this line segment and another segment.
double	distance(Point point) Computes the distance between this line segment and a given point.
double	distanceAlong(double x, double y)
double	distanceAlong(Point point)
double	distancePerpendicular(Point p) Computes the perpendicular distance between the (infinite) line defined by this line segment and a point.
boolean	equals(LineSegment segment)
boolean	equals(Object o) Returns true if other has the same values for its points.
boolean	equalsTopo(LineSegment other) Returns true if other is topologically equal to this LineSegment (e.g.
LineSegment	extend(double startDistance, double endDistance)
int	getAxisCount()
double	getElevation(Point point)
LineSegment	getIntersection(BoundingBox boundingBox)
Geometry	getIntersection(LineSegment lineSegment2)
double	getLength() Computes the length of the line segment.
Point	getP0()
Point	getP1()
int	getVertexCount() Returns the count of this Geometrys vertices.
Point	intersection(LineSegment line) Computes an intersection point between two line segments, if there is one.
boolean	intersects(Point point, double maxDistance)
boolean	isEmpty() Tests whether the set of points covered by this Geometry is empty.
boolean	isEndPoint(Point point)
boolean	isHorizontal() Tests whether the segment is horizontal.
boolean	isPerpendicularTo(Point point)
boolean	isPointOnLineMiddle(Point point, double maxDistance)
boolean	isVertical() Tests whether the segment is vertical.
boolean	isWithinDistance(Point point, double distance)
boolean	isZeroLength()
Point	lineIntersection(LineSegment line) Computes the intersection point of the lines of infinite extent defined by two line segments (if there is one).
Point	midPoint() Computes the midpoint of the segment
LineSegment	normalize() Puts the line segment into a normalized form.
int	orientationIndex(LineSegment seg) Determines the orientation of a LineSegment relative to this segment.
int	orientationIndex(Point p) Determines the orientation index of a Coordinates relative to this segment.
Point	pointAlong(double segmentLengthFraction) Computes the Coordinates that lies a given fraction along the line defined by this segment.
Point	pointAlongOffset(double segmentLengthFraction, double offsetDistance) Computes the Coordinates that lies a given fraction along the line defined by this segment and offset from the segment by a given distance.
LineSegment	project(LineSegment seg) Project a line segment onto this line segment and return the resulting line segment.
Point	project(Point point) Compute the projection of a point onto the line determined by this line segment.
double	projectCoordinate(int axisIndex, double projectionFactor)
double	projectionFactor(double x, double y)
double	projectionFactor(Point point) Computes the Projection Factor for the projection of the point p onto this LineSegmentDouble.
LineSegment	reverse() Reverses the direction of the line segment.
double	segmentFraction(Point inputPt) Computes the fraction of distance (in [0.0, 1.0]) that the projection of a point occurs along this line segment.
boolean	touchesEnd(LineSegment closestSegment)

Methods inherited from class com.revolsys.jts.geom.impl.AbstractLineString

appendVertex, compareToSameClass, computeBoundingBox, convertCoordinates, copy, deleteVertex, deleteVertex, distance, doEquals, equals, equalsExact, equalsVertex, equalsVertex, equalsVertex, equalsVertex, equalsVertex, getBoundary, getBoundaryDimension, getCoordinates, getCoordinatesList, getDataType, getDimension, getEndPoint, getM, getMinVertexCount, getPoint, getPoint, getPointWithin, getSegment, getSegmentCount, getStartPoint, getToVertex, getVertex, getX, getY, getZ, hasVertex, insertVertex, intersects, isClockwise, isClosed, isCounterClockwise, isEquivalentClass, isRing, merge, merge, move, moveCoordinates, moveVertex, moveVertex, orientationIndex, points, prepare, segments, split, subLine, subLine, subLine, subLine, toClockwise, toCounterClockwise, vertices

Methods inherited from class com.revolsys.jts.geom.impl.AbstractGeometry

buffer, buffer, buffer, checkNotGeometryCollection, compare, contains, containsProperly, convert, convexHull, coveredBy, covers, createVertexId, crosses, difference, disjoint, distance, envelopeCovers, envelopesIntersect, equal, equals, equals, equalsExact, equalsNorm, equalsTopo, geometries, getArea, getBoundingBox, getCentroid, getClassSortIndex, getCoordinateSystem, getEnvelope, getGeometries, getGeometries, getGeometry, getGeometryComponents, getGeometryCount, getGeometryFactory, getGeometryType, getInteriorPoint, getNonZeroGeometryFactory, getSrid, getUserData, getVertexIndex, hashCode, hasInvalidXyCoordinates, hasNonEmptyElements, hasNullElements, intersection, intersects, isAnyTargetComponentInTest, isGeometryCollection, isRectangle, isSimple, isValid, isWithinDistance, overlaps, relate, relate, setUserData, setVertexIndex, symDifference, toString, touches, toWkt, union, union, within

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.revolsys.jts.geom.segment.LineSegment

getBoundingBox, getCoordinate, getGeometryFactory

Methods inherited from interface com.revolsys.jts.geom.LineString

distance, equals, equalsVertex, equalsVertex, equalsVertex, equalsVertex, equalsVertex, getCoordinates, getCoordinatesList, getEndPoint, getM, getPoint, getSegmentCount, getStartPoint, getX, getY, getZ, hasVertex, isClockwise, isClosed, isCounterClockwise, isRing, merge, merge, move, moveVertex, points, prepare, split, subLine, subLine, subLine, subLine

Methods inherited from interface com.revolsys.jts.geom.Geometry

appendVertex, buffer, buffer, buffer, compareToSameClass, contains, containsProperly, convert, convexHull, copy, coveredBy, covers, crosses, deleteVertex, difference, disjoint, distance, equal, equals, equals, equalsExact, equalsExact, equalsNorm, equalsTopo, geometries, getArea, getBoundary, getBoundaryDimension, getCentroid, getClassSortIndex, getCoordinateSystem, getDimension, getEnvelope, getGeometries, getGeometries, getGeometry, getGeometryComponents, getGeometryCount, getGeometryType, getInteriorPoint, getPoint, getPointWithin, getSegment, getSrid, getToVertex, getUserData, getVertex, hashCode, hasInvalidXyCoordinates, insertVertex, intersection, intersects, intersects, isRectangle, isSimple, isValid, isWithinDistance, moveVertex, overlaps, relate, relate, segments, setUserData, symDifference, toClockwise, toCounterClockwise, touches, toWkt, union, union, vertices, within

Methods inherited from interface com.revolsys.data.types.DataTypeProxy

getDataType

Constructor Detail

AbstractLineSegment

public AbstractLineSegment()

Method Detail

angle

public double angle()

Computes the angle that the vector defined by this segment makes with the X-axis. The angle will be in the range [ -PI, PI ] radians.

Specified by:

angle in interface LineSegment

Returns:

the angle this segment makes with the X-axis (in radians)

clone

public AbstractLineSegment clone()

Description copied from class: AbstractLineString

Creates and returns a full copy of this LineString object. (including all coordinates contained by it).

Specified by:

clone in interface Geometry

Specified by:

clone in interface LineString

Overrides:

clone in class AbstractLineString

Returns:

a clone of this instance

closestPoint

public Point closestPoint(Point point)

Computes the closest point on this line segment to another point.

Specified by:

closestPoint in interface LineSegment

Parameters:

point - the point to find the closest point to

Returns:

a Point which is the closest point on the line segment to the point p

closestPoints

public Point[] closestPoints(LineSegment line)

Computes the closest points on two line segments.

Specified by:

closestPoints in interface LineSegment

Parameters:

line - the segment to find the closest point to

Returns:

a pair of Point which are the closest points on the line segments

compareTo

protected int compareTo(int index,
            LineSegment other)

compareTo

public int compareTo(Object other)

Compares this object with the specified object for order. Uses the standard lexicographic ordering for the points in the LineSegmentDouble.

Specified by:

compareTo in interface Geometry

Specified by:

compareTo in interface Comparable<Object>

Overrides:

compareTo in class AbstractGeometry

Parameters:

o - the LineSegmentDouble with which this LineSegmentDouble is being compared

Returns:

a negative integer, zero, or a positive integer as this LineSegmentDouble is less than, equal to, or greater than the specified LineSegmentDouble

convert

public <V extends Geometry> V convert(GeometryFactory geometryFactory)

Description copied from interface: Geometry

Convert the geometry to the requried geometry factory. Projecting to the required coordinate system and applying the precision model. If the geometry factory is the same as this geometries factory then the geometry will be returned.

Specified by:

convert in interface Geometry

Overrides:

convert in class AbstractGeometry

Parameters:

geometryFactory - The geometry factory to convert the geometry to.

Returns:

The converted geometry

createLineSegment

protected LineSegment createLineSegment(GeometryFactory geometryFactory,
                            int axisCount,
                            double... coordinates)

createPoint

protected Point createPoint(GeometryFactory geometryFactory,
                double... coordinates)

distance

public double distance(double x,
              double y)

Specified by:

distance in interface LineSegment

distance

public double distance(LineSegment line)

Description copied from interface: LineSegment

Computes the distance between this line segment and another segment.

Specified by:

distance in interface LineSegment

Returns:

the distance to the other segment

distance

public double distance(Point point)

Computes the distance between this line segment and a given point.

Specified by:

distance in interface LineSegment

Returns:

the distance from this segment to the given point

distanceAlong

public double distanceAlong(double x,
                   double y)

Specified by:

distanceAlong in interface LineSegment

distanceAlong

public double distanceAlong(Point point)

Specified by:

distanceAlong in interface LineSegment

distancePerpendicular

public double distancePerpendicular(Point p)

Computes the perpendicular distance between the (infinite) line defined by this line segment and a point.

Specified by:

distancePerpendicular in interface LineSegment

Returns:

the perpendicular distance between the defined line and the given point

equals

public boolean equals(LineSegment segment)

Specified by:

equals in interface LineSegment

equals

public boolean equals(Object o)

Returns true if other has the same values for its points.

Specified by:

equals in interface Geometry

Overrides:

equals in class AbstractGeometry

Parameters:

o - a LineSegment with which to do the comparison.

Returns:

true if other is a LineSegment with the same values for the x and y ordinates.

See Also:

AbstractGeometry.equals(2,Geometry), AbstractGeometry.hashCode(), #norm(), AbstractGeometry.normalize()

equalsTopo

public boolean equalsTopo(LineSegment other)

Returns true if other is topologically equal to this LineSegment (e.g. irrespective of orientation).

Specified by:

equalsTopo in interface LineSegment

Parameters:

other - a LineSegment with which to do the comparison.

Returns:

true if other is a LineSegment with the same values for the x and y ordinates in forwards or reverse order.

extend

public LineSegment extend(double startDistance,
                 double endDistance)

getAxisCount

public int getAxisCount()

Specified by:

getAxisCount in interface Geometry

Specified by:

getAxisCount in interface LineSegment

Overrides:

getAxisCount in class AbstractGeometry

getElevation

public double getElevation(Point point)

Specified by:

getElevation in interface LineSegment

getIntersection

public LineSegment getIntersection(BoundingBox boundingBox)

Specified by:

getIntersection in interface LineSegment

getIntersection

public Geometry getIntersection(LineSegment lineSegment2)

Specified by:

getIntersection in interface LineSegment

getLength

public double getLength()

Computes the length of the line segment.

Specified by:

getLength in interface Geometry

Overrides:

getLength in class AbstractLineString

Returns:

the length of the line segment

getP0

public Point getP0()

Specified by:

getP0 in interface LineSegment

getP1

public Point getP1()

Specified by:

getP1 in interface LineSegment

getVertexCount

public int getVertexCount()

Description copied from interface: Geometry

Returns the count of this Geometrys vertices. The Geometry s contained by composite Geometrys must be Geometry's; that is, they must implement getNumPoints

Specified by:

getVertexCount in interface Geometry

Returns:

the number of vertices in this Geometry

intersection

public Point intersection(LineSegment line)

Computes an intersection point between two line segments, if there is one. There may be 0, 1 or many intersection points between two segments. If there are 0, null is returned. If there is 1 or more, exactly one of them is returned (chosen at the discretion of the algorithm). If more information is required about the details of the intersection, the RobustLineIntersector class should be used.

Specified by:

intersection in interface LineSegment

Parameters:

line - a line segment

Returns:

an intersection point, or null if there is none

See Also:

RobustLineIntersector

intersects

public boolean intersects(Point point,
                 double maxDistance)

Specified by:

intersects in interface LineSegment

isEmpty

public boolean isEmpty()

Description copied from class: AbstractGeometry

Tests whether the set of points covered by this Geometry is empty.

Specified by:

isEmpty in interface Geometry

Specified by:

isEmpty in class AbstractGeometry

Returns:

true if this Geometry does not cover any points

isEndPoint

public boolean isEndPoint(Point point)

Specified by:

isEndPoint in interface LineSegment

isHorizontal

public boolean isHorizontal()

Tests whether the segment is horizontal.

Specified by:

isHorizontal in interface LineSegment

Returns:

true if the segment is horizontal

isPerpendicularTo

public boolean isPerpendicularTo(Point point)

Specified by:

isPerpendicularTo in interface LineSegment

isPointOnLineMiddle

public boolean isPointOnLineMiddle(Point point,
                          double maxDistance)

Specified by:

isPointOnLineMiddle in interface LineSegment

isVertical

public boolean isVertical()

Tests whether the segment is vertical.

Specified by:

isVertical in interface LineSegment

Returns:

true if the segment is vertical

isWithinDistance

public boolean isWithinDistance(Point point,
                       double distance)

isZeroLength

public boolean isZeroLength()

Specified by:

isZeroLength in interface LineSegment

lineIntersection

public Point lineIntersection(LineSegment line)

Computes the intersection point of the lines of infinite extent defined by two line segments (if there is one). There may be 0, 1 or an infinite number of intersection points between two lines. If there is a unique intersection point, it is returned. Otherwise, null is returned. If more information is required about the details of the intersection, the RobustLineIntersector class should be used.

Specified by:

lineIntersection in interface LineSegment

Parameters:

line - a line segment defining an straight line with infinite extent

Returns:

an intersection point, or null if there is no point of intersection or an infinite number of intersection points

See Also:

RobustLineIntersector

midPoint

public Point midPoint()

Computes the midpoint of the segment

Specified by:

midPoint in interface LineSegment

Returns:

the midpoint of the segment

normalize

public LineSegment normalize()

Puts the line segment into a normalized form. This is useful for using line segments in maps and indexes when topological equality rather than exact equality is desired. A segment in normalized form has the first point smaller than the second (according to the standard ordering on Coordinates).

Specified by:

normalize in interface Geometry

Specified by:

normalize in interface LineString

Specified by:

normalize in interface LineSegment

Overrides:

normalize in class AbstractLineString

Returns:

a normalized copy of this geometry.

See Also:

AbstractGeometry.normalize()

orientationIndex

public int orientationIndex(LineSegment seg)

Determines the orientation of a LineSegment relative to this segment. The concept of orientation is specified as follows: Given two line segments A and L,

A is to the left of a segment L if A lies wholly in the closed half-plane lying to the left of L
• A is to the right of a segment L if A lies wholly in the closed half-plane lying to the right of L
• otherwise, A has indeterminate orientation relative to L. This happens if A is collinear with L or if A crosses the line determined by L.

Specified by:

orientationIndex in interface LineSegment

Parameters:

seg - the LineSegment to compare

Returns:

1 if seg is to the left of this segment

orientationIndex

public int orientationIndex(Point p)

Determines the orientation index of a Coordinates relative to this segment. The orientation index is as defined in CGAlgorithms#computeOrientation.

Specified by:

orientationIndex in interface LineSegment

Parameters:

p - the coordinate to compare

Returns:

1 (LEFT) if p is to the left of this segment

See Also:

CGAlgorithms#computeOrientation(Coordinate, Coordinate, Coordinate)

pointAlong

public Point pointAlong(double segmentLengthFraction)

Computes the Coordinates that lies a given fraction along the line defined by this segment. A fraction of 0.0 returns the start point of the segment; a fraction of 1.0 returns the end point of the segment. If the fraction is < 0.0 or > 1.0 the point returned will lie before the start or beyond the end of the segment.

Specified by:

pointAlong in interface LineSegment

Parameters:

segmentLengthFraction - the fraction of the segment length along the line

Returns:

the point at that distance

pointAlongOffset

public Point pointAlongOffset(double segmentLengthFraction,
                     double offsetDistance)

Computes the Coordinates that lies a given fraction along the line defined by this segment and offset from the segment by a given distance. A fraction of 0.0 offsets from the start point of the segment; a fraction of 1.0 offsets from the end point of the segment. The computed point is offset to the left of the line if the offset distance is positive, to the right if negative.

Specified by:

pointAlongOffset in interface LineSegment

Parameters:

segmentLengthFraction - the fraction of the segment length along the line

offsetDistance - the distance the point is offset from the segment (positive is to the left, negative is to the right)

Returns:

the point at that distance and offset

Throws:

IllegalStateException - if the segment has zero length

project

public LineSegment project(LineSegment seg)

Project a line segment onto this line segment and return the resulting line segment. The returned line segment will be a subset of the target line line segment. This subset may be null, if the segments are oriented in such a way that there is no projection.

Note that the returned line may have zero length (i.e. the same endpoints). This can happen for instance if the lines are perpendicular to one another.

Specified by:

project in interface LineSegment

Parameters:

seg - the line segment to project

Returns:

the projected line segment, or null if there is no overlap

project

public Point project(Point point)

Compute the projection of a point onto the line determined by this line segment.

Note that the projected point may lie outside the line segment. If this is the case, the projection factor will lie outside the range [0.0, 1.0].

Specified by:

project in interface LineSegment

projectCoordinate

public double projectCoordinate(int axisIndex,
                       double projectionFactor)

Specified by:

projectCoordinate in interface LineSegment

projectionFactor

public double projectionFactor(double x,
                      double y)

Specified by:

projectionFactor in interface LineSegment

projectionFactor

public double projectionFactor(Point point)

Computes the Projection Factor for the projection of the point p onto this LineSegmentDouble. The Projection Factor is the constant r by which the vector for this segment must be multiplied to equal the vector for the projection of p on the line defined by this segment.

The projection factor will lie in the range (-inf, +inf), or be NaN if the line segment has zero length..

Specified by:

projectionFactor in interface LineSegment

Parameters:

p - the point to compute the factor for

Returns:

the projection factor for the point

reverse

public LineSegment reverse()

Reverses the direction of the line segment.

Specified by:

reverse in interface Geometry

Specified by:

reverse in interface LineString

Specified by:

reverse in interface LineSegment

Overrides:

reverse in class AbstractLineString

Returns:

a LineString with coordinates in the reverse order

segmentFraction

public double segmentFraction(Point inputPt)

Computes the fraction of distance (in [0.0, 1.0]) that the projection of a point occurs along this line segment. If the point is beyond either ends of the line segment, the closest fractional value (0.0 or 1.0) is returned.

Essentially, this is the projectionFactor(double, double) clamped to the range [0.0, 1.0]. If the segment has zero length, 1.0 is returned.

Specified by:

segmentFraction in interface LineSegment

Parameters:

inputPt - the point

Returns:

the fraction along the line segment the projection of the point occurs

touchesEnd

public boolean touchesEnd(LineSegment closestSegment)

Specified by:

touchesEnd in interface LineSegment