LineSegment class

Represents a line segment defined by two {@link Coordinate}s. Provides methods to compute various geometric properties and relationships of line segments.

This class is designed to be easily mutable (to the extent of having its contained points ). This supports a common pattern of reusing a single LineSegment object as a way of computing segment properties on the segments defined by arrays or lists of {@link Coordinate}s.

@version 1.7

Implemented types
Implementers

Properties

hashCode → int
The hash code for this object.
no setteroverride
p0 ↔ Coordinate
getter/setter pair
p1 ↔ Coordinate
getter/setter pair
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

angle() → double
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.
closestPoint(Coordinate p) → Coordinate
Computes the closest point on this line segment to another point. @param p the point to find the closest point to @return a Coordinate which is the closest point on the line segment to the point p
closestPoints(LineSegment line) → List<Coordinate>
Computes the closest points on two line segments.
compareTo(dynamic o) → int
Compares this object with the specified object for order. Uses the standard lexicographic ordering for the points in the LineSegment.
override
distance(LineSegment ls) → double
Computes the distance between this line segment and another segment.
distanceCoord(Coordinate p) → double
Computes the distance between this line segment and a given point.
distancePerpendicular(Coordinate p) → double
Computes the perpendicular distance between the (infinite) line defined by this line segment and a point.
equals(Object o) → bool
Returns true if other has the same values for its points.
equalsTopo(LineSegment other) → bool
Returns true if other is topologically equal to this LineSegment (e.g. irrespective of orientation).
getCoordinate(int i) → Coordinate
getLength() → double
Computes the length of the line segment. @return the length of the line segment
intersection(LineSegment line) → Coordinate?
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 {@link RobustLineIntersector} class should be used.
isHorizontal() → bool
Tests whether the segment is horizontal.
isVertical() → bool
Tests whether the segment is vertical.
lineIntersection(LineSegment line) → Coordinate?
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 {@link RobustLineIntersector} class should be used.
maxX() → double
Gets the maximum X ordinate. @return the maximum X ordinate
maxY() → double
Gets the maximum Y ordinate. @return the maximum Y ordinate
midPoint() → Coordinate
Computes the midpoint of the segment
minX() → double
Gets the minimum X ordinate. @return the minimum X ordinate
minY() → double
Gets the minimum Y ordinate. @return the minimum Y ordinate
normalize() → void
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 {@link Coordinate}).
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
orientationIndex(LineSegment seg) → int
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,
orientationIndexCoord(Coordinate p) → int
Determines the orientation index of a {@link Coordinate} relative to this segment. The orientation index is as defined in {@link Orientation#computeOrientation}.
pointAlong(double segmentLengthFraction) → Coordinate
Computes the {@link Coordinate} 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.
pointAlongOffset(double segmentLengthFraction, double offsetDistance) → Coordinate
Computes the {@link Coordinate} 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.
project(LineSegment seg) → LineSegment?
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.
projectCoord(Coordinate p) → Coordinate
Compute the projection of a point onto the line determined by this line segment.
projectionFactor(Coordinate p) → double
Computes the Projection Factor for the projection of the point p onto this LineSegment. 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.
reverse() → void
Reverses the direction of the line segment.
segmentFraction(Coordinate inputPt) → double
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.
setCoordinates(Coordinate p0, Coordinate p1) → void
setCoordinatesFromLinesegment(LineSegment ls) → void
toGeometry(GeometryFactory geomFactory) → LineString
Creates a LineString with the same coordinates as this segment
toString() → String
A string representation of this object.
override

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Methods

midPointCoords(Coordinate p0, Coordinate p1) → Coordinate
Computes the midpoint of a segment