Package gov.nasa.worldwind.geom

Class Line

java.lang.Object

gov.nasa.worldwind.geom.Line

public final class Line
extends java.lang.Object

Constructor Summary

Constructors

Constructor	Description
Line(Vec4 origin, Vec4 direction)

Method Summary

Modifier and Type	Method	Description
static Vec4[]	clipToFrustum(Vec4 pa, Vec4 pb, Frustum frustum)	Clip a line segment to a frustum, returning the end points of the portion of the segment that is within the frustum.
double	distanceTo(Vec4 p)	Calculate the shortests distance between this line and a specified Vec4.
static double	distanceToSegment(Vec4 p0, Vec4 p1, Vec4 p)
boolean	equals(java.lang.Object o)	Performs a comparison to test whether this Object is internally identical to the other Object o.
static Line	fromSegment(Vec4 pa, Vec4 pb)	Create the line containing a line segement between two points.
Vec4	getDirection()
Vec4	getOrigin()
Vec4	getPointAt(double t)
int	hashCode()
boolean	isPointBehindLineOrigin(Vec4 point)	Determine if a point is behind the Line's origin.
Vec4	nearestIntersectionPoint(Intersection[] intersections)
static Vec4	nearestPointOnSegment(Vec4 p0, Vec4 p1, Vec4 p)	Finds the closest point to a third point of a segment defined by two points.
Vec4	nearestPointTo(Vec4 p)
double	selfDot()
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Line

public Line(Vec4 origin,
            Vec4 direction)

Parameters:

origin - the origin of the line being constructed

direction - the direction of the line being constructed

Throws:

java.lang.IllegalArgumentException - if origin is null, or direction is null or has zero length

Method Detail

fromSegment

public static Line fromSegment(Vec4 pa,
                               Vec4 pb)

Create the line containing a line segement between two points.

Parameters:

pa - the first point of the line segment.

pb - the second point of the line segment.

Returns:

The line containing the two points.

Throws:

java.lang.IllegalArgumentException - if either point is null or they are coincident.

getDirection

public final Vec4 getDirection()

getOrigin

public final Vec4 getOrigin()

getPointAt

public final Vec4 getPointAt(double t)

selfDot

public final double selfDot()

equals

public final boolean equals(java.lang.Object o)

Performs a comparison to test whether this Object is internally identical to the other Object o. This method takes into account both direction and origin, so two lines which may be equivalent may not be considered equal.

Overrides:

equals in class java.lang.Object

Parameters:

o - the object to be compared against.

Returns:

true if these two objects are equal, false otherwise

hashCode

public final int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

nearestPointTo

public final Vec4 nearestPointTo(Vec4 p)

distanceTo

public final double distanceTo(Vec4 p)

Calculate the shortests distance between this line and a specified Vec4. This method returns a positive distance.

Parameters:

p - the Vec4 whose distance from this Line will be calculated

Returns:

the distance between this Line and the specified Vec4

Throws:

java.lang.IllegalArgumentException - if p is null

nearestPointOnSegment

public static Vec4 nearestPointOnSegment(Vec4 p0,
                                         Vec4 p1,
                                         Vec4 p)

Finds the closest point to a third point of a segment defined by two points.

Parameters:

p0 - The first endpoint of the segment.

p1 - The second endpoint of the segment.

p - The point outside the segment whose closest point on the segment is desired.

Returns:

The closest point on (p0, p1) to p. Note that this will be p0 or p1 themselves whenever the closest point on the line defined by p0 and p1 is outside the segment (i.e., the results are bounded by the segment endpoints).

distanceToSegment

public static double distanceToSegment(Vec4 p0,
                                       Vec4 p1,
                                       Vec4 p)

clipToFrustum

public static Vec4[] clipToFrustum(Vec4 pa,
                                   Vec4 pb,
                                   Frustum frustum)

Clip a line segment to a frustum, returning the end points of the portion of the segment that is within the frustum.

Parameters:

pa - the first point of the segment.

pb - the second point of the segment.

frustum - the frustum.

Returns:

The two points at which the segment intersects the frustum, or null if the segment does not intersect and the frustum does not fully contain it. If the segment is coincident with a plane of the frustum, the returned segment is the portion of the original segment on that plane, clipped to the other frustum planes.

isPointBehindLineOrigin

public boolean isPointBehindLineOrigin(Vec4 point)

Determine if a point is behind the Line's origin.

Parameters:

point - The point to test.

Returns:

true if point is behind this Line's origin, false otherwise.

nearestIntersectionPoint

public Vec4 nearestIntersectionPoint(Intersection[] intersections)