jwo.landserf.structure
Class Edge

java.lang.Object
  jwo.landserf.structure.Edge

All Implemented Interfaces:

Serializable

public class Edge

extends Object

implements Serializable

Stores a 2d topological directional edge used for connecting 2d or higher dimensional features. Edge consists of 2 nodes P1 and P2 orderd P1->P2. Adapted from Zhao and Saalfeld, 1996.

Version:

2.2, 28th February, 2002.

Author:

Jo Wood

See Also:

Node, Triangle, Serialized Form

Field Summary

static int	ALIGNED Indicates location aligned with directed edge.
static int	LEFT Indicates location to the left of directed edge.
static int	RIGHT Indicates location to the right of directed edge.

Constructor Summary

Edge(Node p1, Node p2)
Creates an edge from the two given nodes.

Method Summary

void	calcEquation() Calculates the equation of the straight line that this edge forms a part of.
int	calcSide(Node node) Determines where the edge is in relation to a given node.
Edge	getInvEdge() Returns this edge's inverse (P2->P1).
float	getLength() Reports the 2d length of the edge.
Edge	getNextEdge() Returns the next anticlockwise edge in the sequence.
Edge	getNextHullEdge() Returns the next convex hull edge in the sequence.
Node	getP1() Returns the first point associated with this edge.
Node	getP2() Returns the second point associated with this edge.
Triangle	getTriang() Returns the triangle containing this edge.
float	getVersion() Reports the version of the object.
void	linkSymm(Edge edge) Creates a link to the symmetrical inverse of the supplied edge.
Edge	makeSymm() Creates a symmetrical inverse of this edge.
Edge	mostLeft() Traverses edge network and returns the left-most edge.
Edge	mostRight() Traverses edge network and returns the right-most edge.
void	p1ToEdge() Sets this edge to be the one pointed to by the first node.
void	setInvEdge(Edge edge) Sets the inverse (P2->P1) edge.
void	setNextEdge(Edge edge) Sets the next edge in the sequence.
void	setNextHullEdge(Edge edge) Sets the next convex hull edge in the sequence.
void	setTriang(Triangle triangle) Sets the triangle of which this edge forms a part.
void	setVersion(float version) Sets the version number of this object.
String	toString() Reports the coordinates of this edge.
void	update(Node p1, Node p2) Updates the topology and equation representing this edge.

Methods inherited from class java.lang.Object

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

Field Detail

RIGHT

public static final int RIGHT

Indicates location to the right of directed edge.

See Also:

Constant Field Values

ALIGNED

public static final int ALIGNED

Indicates location aligned with directed edge.

See Also:

Constant Field Values

LEFT

public static final int LEFT

Indicates location to the left of directed edge.

See Also:

Constant Field Values

Constructor Detail

Edge

public Edge(Node p1,
            Node p2)

Creates an edge from the two given nodes.

Parameters:

p1 - First node of edge.

p2 - Second node of edge.

Method Detail

update

public void update(Node p1,
                   Node p2)

Updates the topology and equation representing this edge.

Parameters:

p1 - First node of edge.

p2 - Second node of edge.

makeSymm

public Edge makeSymm()

Creates a symmetrical inverse of this edge.

Returns:

Symmetrical inverse of this edge.

linkSymm

public void linkSymm(Edge edge)

Creates a link to the symmetrical inverse of the supplied edge.

Parameters:

edge - Symmetrical inverse of this edge.

calcSide

public int calcSide(Node node)

Determines where the edge is in relation to a given node.

Parameters:

node - Node to test with respect to this edge.

Returns:

Relative position of line (LEFT, RIGHT or ALIGNED).

calcEquation

public void calcEquation()

Calculates the equation of the straight line that this edge forms a part of.

p1ToEdge

public void p1ToEdge()

Sets this edge to be the one pointed to by the first node.

mostLeft

public Edge mostLeft()

Traverses edge network and returns the left-most edge.

Returns:

Left-most edge in a connected network.

mostRight

public Edge mostRight()

Traverses edge network and returns the right-most edge.

Returns:

Right-most edge in a connected network.

toString

public String toString()

Reports the coordinates of this edge. Overrides the method in Object.

getP1

public Node getP1()

Returns the first point associated with this edge.

Returns:

First node associated with this edge.

getP2

public Node getP2()

Returns the second point associated with this edge.

Returns:

Second point associated with this edge.

getLength

public float getLength()

Reports the 2d length of the edge.

Returns:

2d length of the edge.

getNextEdge

public Edge getNextEdge()

Returns the next anticlockwise edge in the sequence.

Returns:

Next anticlockwise edge.

setNextEdge

public void setNextEdge(Edge edge)

Sets the next edge in the sequence.

Parameters:

edge - Edge to add to sequence.

getInvEdge

public Edge getInvEdge()

Returns this edge's inverse (P2->P1).

Returns:

Inverse edge.

setInvEdge

public void setInvEdge(Edge edge)

Sets the inverse (P2->P1) edge.

Parameters:

edge - Inverse of this edge.

getNextHullEdge

public Edge getNextHullEdge()

Returns the next convex hull edge in the sequence.

Returns:

Next convex hull edge.

setNextHullEdge

public void setNextHullEdge(Edge edge)

Sets the next convex hull edge in the sequence.

Parameters:

edge - Next convex hull edge.

getTriang

public Triangle getTriang()

Returns the triangle containing this edge.

Returns:

Triangle containing this edge.

setTriang

public void setTriang(Triangle triangle)

Sets the triangle of which this edge forms a part.

Parameters:

triangle - Triangle that this edge belongs to.

getVersion

public float getVersion()

Reports the version of the object. This can be useful when serialising future (changed) versions of this class.

Returns:

Version number of this object.

setVersion

public void setVersion(float version)

Sets the version number of this object.

Parameters:

version - Version number of this object.