org.eclipse.gef.geometry.projective

Class Straight3D

java.lang.Object

org.eclipse.gef.geometry.projective.Straight3D

public final class Straight3D
extends java.lang.Object

A two-dimensional infinite line that is defined by three coordinates of which the third is a so called homogeneous coordinate. Calculations are easier to do on such lines:

• the point of intersection between two lines is the cross product of their respective three dimensional vectors
• the distance from a point to the line is the scalar product of both three dimensional vectors

This is the complement to the Vector3D which represents a Point with a third, homogeneous coordinate.

Method Summary

Modifier and Type	Method and Description
Vector3D	getIntersection(Straight3D other) Returns the intersection between this and the given other Straight3D.
Straight3D	getOrtho() Returns the orthogonal Straight3D through this Straight3D 's start Vector3D.
Straight3D	getOrtho(Vector3D vp) Returns the orthogonal Straight3D through the given Vector3D.
double	getSignedDistanceCW(Vector3D vp) Returns the clock-wise signed distance of the given Vector3D to this Straight3D.
static Straight3D	through(Vector3D start, Vector3D end) Constructs a new Straight3D through the given start and end Vector3Ds.
Straight	toStraight() Transfer this Straight3D into a representative Straight.

Methods inherited from class java.lang.Object

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

Method Detail

through

public static Straight3D through(Vector3D start,
                                 Vector3D end)

Constructs a new Straight3D through the given start and end Vector3Ds.

Parameters:

start - The first Vector3D which lies on to the Straight3D which is constructed.

end - The second Vector3D which lies on the Straight3D which is constructed.

Returns:

a new Straight3D through start and end Vector3Ds

getIntersection

public Vector3D getIntersection(Straight3D other)

Returns the intersection between this and the given other Straight3D. The intersection is the cross product of both Vector3Ds.

Parameters:

other - The Straight3D for which intersections are computed.

Returns:

the intersection between this and the given other Straight3D

getOrtho

public Straight3D getOrtho()

Returns the orthogonal Straight3D through this Straight3D 's start Vector3D.

Returns:

the orthogonal Straight3D through this Straight3D 's start Vector3D

getOrtho

public Straight3D getOrtho(Vector3D vp)

Returns the orthogonal Straight3D through the given Vector3D.

Parameters:

vp - The Vector3D which lies on the orthogonal Straight3D.

Returns:

the orthogonal Straight3D through the given Vector3D

getSignedDistanceCW

public double getSignedDistanceCW(Vector3D vp)

Returns the clock-wise signed distance of the given Vector3D to this Straight3D. The clock-wise signed distance is the dot product of the both Vector3Ds divided by the length of the line's (x,y) vector: |(x,y)|.

Parameters:

vp - The Vector3D to which the distance is computed.

Returns:

the clock-wise signed distance of the Vector3D to this Straight3D

toStraight

public Straight toStraight()

Transfer this Straight3D into a representative Straight.

Returns:

a representative Straight