org.locationtech.jts.algorithm

Class Intersection

java.lang.Object

org.locationtech.jts.algorithm.Intersection

public class Intersection
extends Object

Functions to compute intersection points between lines and line segments.

In general it is not possible to compute the intersection point of two lines exactly, due to numerical roundoff. This is particularly true when the lines are nearly parallel. These routines uses numerical conditioning on the input values to ensure that the computed value is very close to the correct value.

The Z-ordinate is ignored, and not populated.

Author:

Martin Davis

Constructor Summary

Constructors

Constructor and Description
Intersection()

Method Summary

Modifier and Type	Method and Description
static Coordinate	intersection(Coordinate p1, Coordinate p2, Coordinate q1, Coordinate q2) Computes the intersection point of two lines.
static Coordinate	lineSegment(Coordinate line1, Coordinate line2, Coordinate seg1, Coordinate seg2) Computes the intersection point of a line and a line segment (if any).

Methods inherited from class java.lang.Object

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

Constructor Detail

Intersection

public Intersection()

Method Detail

intersection

public static Coordinate intersection(Coordinate p1,
                                      Coordinate p2,
                                      Coordinate q1,
                                      Coordinate q2)

Computes the intersection point of two lines. If the lines are parallel or collinear this case is detected and null is returned.

Parameters:

p1 - an endpoint of line 1

p2 - an endpoint of line 1

q1 - an endpoint of line 2

q2 - an endpoint of line 2

Returns:

the intersection point between the lines, if there is one, or null if the lines are parallel or collinear

See Also:

CGAlgorithmsDD.intersection(Coordinate, Coordinate, Coordinate, Coordinate)

lineSegment

public static Coordinate lineSegment(Coordinate line1,
                                     Coordinate line2,
                                     Coordinate seg1,
                                     Coordinate seg2)

Computes the intersection point of a line and a line segment (if any). There will be no intersection point if:

• the segment does not intersect the line
• the line or the segment are degenerate (have zero length)

If the segment is collinear with the line the first segment endpoint is returned.

Parameters:

line1 - a point on the line

line2 - a point on the line

seg1 - an endpoint of the line segment

seg2 - an endpoint of the line segment

Returns:

the intersection point, or null if it is not possible to find an intersection