ome.util.math.geom2D

Class Line

java.lang.Object

ome.util.math.geom2D.Line

public class Line
extends Object

An orientated line in the Euclidean space R².

Since:

OME2.2

Version:

2.2 (Internal version: $Revision$ $Date: 2005/06/09 15:01:32 $)

Author:

Jean-Marie Burel j.burel@dundee.ac.uk,
Andrea Falconi a.falconi@dundee.ac.uk

Field Summary

Fields

Modifier and Type	Field and Description
PlanePoint	direction The unit vector that, given the origin point, identifies this line.
PlanePoint	origin The origin point of the line.

Constructor Summary

Constructors

Constructor and Description
Line(PlanePoint o, PlanePoint p) Creates a new object to represent the line passing through the o and p points.
Line(PlanePoint p, PlanePoint q, PlanePoint o) Creates a new object to represent the line passing through o and having direction pq.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o) Overridden to reflect equality of abstract values (data object) as opposite to object identity.
PlanePoint	getPoint(double k) Returns the point of this line defined by k.
int	hashCode() Overridden to reflect equality of abstract values (data object) as opposite to object identity.
boolean	lies(PlanePoint p) Tells whether the specified point lies on this line.
boolean	lies(PlanePoint p, boolean positiveOrientation) Tells whether the specified point lies on this line and within the specified orientation.

Methods inherited from class java.lang.Object

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

Field Detail

origin

public final PlanePoint origin

The origin point of the line. Any point (within the line) that falls on the half line that has the same orientation as the direction unit vector is said to have positive orientation — this also includes the origin point. All other points of the line are said to have (strictly) negative orientation.

direction

public final PlanePoint direction

The unit vector that, given the origin point, identifies this line.

Constructor Detail

Line

public Line(PlanePoint o,
    PlanePoint p)

Creates a new object to represent the line passing through the o and p points. The o point is taken to define the origin of the line and the direction is defined by the op vector.

Parameters:

o - The origin of the line. Mustn't be null.

p - A point of the line. Mustn't be null nor the same as o.

Line

public Line(PlanePoint p,
    PlanePoint q,
    PlanePoint o)

Creates a new object to represent the line passing through o and having direction pq. The p and q points are, respectively, the tail and head of the vector pq that is taken to define the direction of the line.

Parameters:

p - Tail of a vector. Mustn't be null.

q - Head of a vector. Mustn't be null nor the same as q.

o - The origin of the line. Mustn't be null.

Method Detail

getPoint

public PlanePoint getPoint(double k)

Returns the point of this line defined by k. More precisely, this method returns the origin+kdirection point.

Parameters:

k - The coefficient to select the point.

Returns:

See above.

lies

public boolean lies(PlanePoint p)

Tells whether the specified point lies on this line.

Parameters:

p - The point to test. Mustn't be null.

Returns:

true if p lies on this line, false otherwise.

lies

public boolean lies(PlanePoint p,
           boolean positiveOrientation)

Tells whether the specified point lies on this line and within the specified orientation. The positiveOrientation parameter is used to specify which side (with respect to the origin) of the line to check. If true, then we check to see whether p falls on the half line that has the same orientation as the direction unit vector — this also includes the origin. If false, we check to see whether p falls on the opposite half line.

Parameters:

p - The point to test. Mustn't be null.

positiveOrientation - true for the positive orientation, false for the strictly negative orientation.

Returns:

true if p lies on this line, false otherwise.

equals

public boolean equals(Object o)

Overridden to reflect equality of abstract values (data object) as opposite to object identity.

Overrides:

equals in class Object

See Also:

Object.equals(Object)

hashCode

public int hashCode()

Overridden to reflect equality of abstract values (data object) as opposite to object identity.

Overrides:

hashCode in class Object

See Also:

Object.hashCode()