org.reprap.geometry.polygons
Class RrHalfPlane

java.lang.Object
  org.reprap.geometry.polygons.RrHalfPlane

public class RrHalfPlane
extends java.lang.Object

Class to hold and manipulate linear half-planes

Field Summary

private boolean	beingDestroyed Flag to prevent cyclic graphs going round forever
private Rr2Point	normal The half-plane is normal*(x, y) + offset <= 0
private double	offset
private RrLine	p Keep the parametric equivalent to save computing it

Constructor Summary

RrHalfPlane(Rr2Point a, Rr2Point b)
Make one from two points on its edge

RrHalfPlane(RrHalfPlane a)
Deep copy

RrHalfPlane(RrLine l)
Convert a parametric line

Method Summary

RrHalfPlane	complement() Change the sense
Rr2Point	cross_point(RrHalfPlane a) The point where another line crosses
Rr2Point	cross_point(RrLine a) Point where a parametric line crosses
double	cross_t(RrLine a) Parameter value where a line crosses
void	destroy() Destroy me and all that I point to
Rr2Point	normal() Get the components
double	offset()
RrHalfPlane	offset(double d) Move
RrLine	pLine() Get the parametric equivalent
static int	same(RrHalfPlane a, RrHalfPlane b, double tolerance) Is another line the same within a tolerance?
java.lang.String	toString() Return the plane as a string
double	value(Rr2Point p) Find the potential value of a point
RrInterval	value(RrRectangle b) Find the potential interval of a box
RrInterval	wipe(RrLine a, RrInterval range) Take a range of parameter values and a line, and find the intersection of that range with the part of the line (if any) on the solid side of the half-plane.

Methods inherited from class java.lang.Object

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

Field Detail

normal

private Rr2Point normal

The half-plane is normal*(x, y) + offset <= 0

offset

private double offset

p

private RrLine p

Keep the parametric equivalent to save computing it

beingDestroyed

private boolean beingDestroyed

Flag to prevent cyclic graphs going round forever

Constructor Detail

RrHalfPlane

public RrHalfPlane(RrLine l)

Convert a parametric line

Parameters:

l -

RrHalfPlane

public RrHalfPlane(Rr2Point a,
                   Rr2Point b)

Make one from two points on its edge

Parameters:

a -

b -

RrHalfPlane

public RrHalfPlane(RrHalfPlane a)

Deep copy

Parameters:

a -

Method Detail

destroy

public void destroy()

Destroy me and all that I point to

pLine

public RrLine pLine()

Get the parametric equivalent

Returns:

parametric equivalent of a line

toString

public java.lang.String toString()

Return the plane as a string

Overrides:

toString in class java.lang.Object

Returns:

string representation

normal

public Rr2Point normal()

Get the components

Returns:

components?

offset

public double offset()

same

public static int same(RrHalfPlane a,
                       RrHalfPlane b,
                       double tolerance)

Is another line the same within a tolerance?

Parameters:

a -

b -

tolerance -

Returns:

0 if the distance between halfplane a and b is less then the tolerance, -1 if one is the complement of the other within the tolerance, otherwise 1

complement

public RrHalfPlane complement()

Change the sense

Returns:

complent of half plane

offset

public RrHalfPlane offset(double d)

Move

Parameters:

d -

Returns:

offset halfplane

value

public double value(Rr2Point p)

Find the potential value of a point

Parameters:

p -

Returns:

potential value of point p

value

public RrInterval value(RrRectangle b)

Find the potential interval of a box

Parameters:

b -

Returns:

potential interval of box b

cross_point

public Rr2Point cross_point(RrHalfPlane a)
                     throws RrParallelLineException

The point where another line crosses

Parameters:

a -

Returns:

cross point

Throws:

RrParallelLineException

cross_t

public double cross_t(RrLine a)
               throws RrParallelLineException

Parameter value where a line crosses

Parameters:

a -

Returns:

parameter value

Throws:

RrParallelLineException

cross_point

public Rr2Point cross_point(RrLine a)
                     throws RrParallelLineException

Point where a parametric line crosses

Parameters:

a -

Returns:

cross point

Throws:

RrParallelLineException

wipe

public RrInterval wipe(RrLine a,
                       RrInterval range)

Take a range of parameter values and a line, and find the intersection of that range with the part of the line (if any) on the solid side of the half-plane.

Parameters:

a -

range -

Returns:

intersection interval