NASA World Wind
gov.nasa.worldwind.geom

## Class Line

• ```public final class Line
extends Object```
• ### Constructor Summary

Constructors
Constructor and Description
```Line(Vec4 origin, Vec4 direction)```
• ### Method Summary

All Methods
Modifier and Type Method and 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(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()`
`String` `toString()`
• ### Methods inherited from class java.lang.Object

`clone, finalize, 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:
`IllegalArgumentException` - if `origin` is null, or `direction` is null or has zero length
• ### Method Detail

• #### 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.
• #### 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:
`IllegalArgumentException` - if `p` is null
• #### distanceToSegment

```public static double distanceToSegment(Vec4 p0,
Vec4 p1,
Vec4 p)```
• #### equals

`public final boolean equals(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 `Object`
Parameters:
`o` - the object to be compared against.
Returns:
true if these two objects are equal, false otherwise
• #### 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:
`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)`
• #### hashCode

`public final int hashCode()`
Overrides:
`hashCode` in class `Object`
• #### 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)`
• #### 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).
• #### nearestPointTo

`public final Vec4 nearestPointTo(Vec4 p)`
• #### selfDot

`public final double selfDot()`
• #### toString

`public String toString()`
Overrides:
`toString` in class `Object`