Class Line

java.lang.Object

cnuphys.adaptiveSwim.geometry.Line

public class Line
extends Object

3D line of the form p(t) = po + t*dp where p(t) is a point on the line, po is one point and dp = (p1-po) where p1 is another point. If this is an infinite line, the t = [-infinity, infinity]. If this is a directed segment, t = [0, 1]

Author:

heddle

Constructor Summary

Constructors

Constructor	Description
Line(double[] p1, double[] p2)	Create a line from two ponts passed as arrays
Line(Line line)	Copy constructor
Line(Point po, Point p1)	Create a line from two points on the line.
Line(Vector v)	Create a line from the origing in the direction of a vector

Method Summary

Modifier and Type	Method	Description
double	distance(double x, double y, double z)	Get the shortest distance between this line (as an infinite line) and a point
double	distance(Point p)	Get the shortest distance between this line (as an infinite line) and a point
Point	getCenter()	Get the center of the line
Vector	getDelP()	Get the p1-po "dP" segment
Point	getEndpoint(int end)	Get one of the endpoints
Point	getP(double t)	Get a point on the line
void	getP(double t, Point p)	Get a point on the line (in place)
Point	getP0()	Get the po "start" point.
Point	getP1()	Get the p1 "end" point.
static void	main(String[] arg)
boolean	pointOnLine(Point p)	Decide whether a point is on the line using the constant TINY as the max distance
boolean	pointOnLine(Point p, double maxDistance)	Decide whether a point is on the line
String	toString()	Get a String representation

Methods inherited from class java.lang.Object

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

Constructor Details

Line

public Line(Point po,
 Point p1)

Create a line from two points on the line. If this is a directed line segment, the line will go from po to p1.

Parameters:

po - one point

p1 - the other point

Line

public Line(double[] p1,
 double[] p2)

Create a line from two ponts passed as arrays

Parameters:

p1 - one point as an xyz array

p2 - another point as an xyz array

Line

public Line(Line line)

Copy constructor

Parameters:

line - the line to copy

Line

public Line(Vector v)

Create a line from the origing in the direction of a vector

Parameters:

v - the vector

Method Details

getP0

public Point getP0()

Get the po "start" point. This is just an arbitrary point on an infinite line, but the starting point if this is a directed line segment

Returns:

the "starting" point.

getDelP

public Vector getDelP()

Get the p1-po "dP" segment

Returns:

dP = p1 - po

getEndpoint

public Point getEndpoint(int end)

Get one of the endpoints

Parameters:

end - one of the Constants START or END

Returns:

the requested endpoint

getP1

public Point getP1()

Get the p1 "end" point. This is just an arbitrary point on an infinite line, but the end point if this is a directed line segment

Returns:

the "end" point.

getP

public Point getP(double t)

Get a point on the line

Parameters:

t - the t parameter. If this is a directed line segment, t should be restricted to [0, 1]

Returns:

a point on the line

getP

public void getP(double t,
 Point p)

Get a point on the line (in place)

Parameters:

t - the t parameter. If this is a directed line segment, t should be restricted to [0, 1]

p - upon return, a point on the line

distance

public double distance(Point p)

Get the shortest distance between this line (as an infinite line) and a point

Parameters:

p - a point

Returns:

the perpendicular distance

distance

public double distance(double x,
 double y,
 double z)

Get the shortest distance between this line (as an infinite line) and a point

Parameters:

x - the x coordinate

y - the y coordinate

z - the z coordinate

Returns:

the perpendicular distance

pointOnLine

public boolean pointOnLine(Point p,
 double maxDistance)

Decide whether a point is on the line

Parameters:

p - the point

maxDistance - the max distance it can be off the line and still considered on the line

Returns:

true if the point is considered on the line

pointOnLine

public boolean pointOnLine(Point p)

Decide whether a point is on the line using the constant TINY as the max distance

Parameters:

p - the point

Returns:

true if the point is considered on the line

toString

public String toString()

Get a String representation

Overrides:

toString in class Object

Returns:

a String representation of the Line

getCenter

public Point getCenter()

Get the center of the line

Returns:

the center of the line

main

public static void main(String[] arg)