com.vividsolutions.jcs.graph
Class DirectedEdge

java.lang.Object
  com.vividsolutions.jcs.graph.DirectedEdge

All Implemented Interfaces:

java.lang.Comparable

Direct Known Subclasses:

PolyDirectedEdge, RoadDirectedEdge

public class DirectedEdge

extends java.lang.Object

implements java.lang.Comparable

Field Summary

protected double	angle
protected static com.vividsolutions.jts.algorithm.RobustCGAlgorithms	cga
protected boolean	edgeDirection
protected Node	from
protected com.vividsolutions.jts.geom.Coordinate	p0
protected com.vividsolutions.jts.geom.Coordinate	p1
protected Edge	parentEdge
protected int	quadrant
protected DirectedEdge	sym
protected Node	to

Constructor Summary

DirectedEdge(Node from, Node to, com.vividsolutions.jts.geom.Coordinate directionPt, boolean edgeDirection)

Method Summary

int	compareDirection(DirectedEdge e) Implements the total order relation:
int	compareTo(java.lang.Object obj)
double	getAngle() Returns the starting angle of this DirectedEdge.
Edge	getEdge()
boolean	getEdgeDirection()
Node	getFromNode()
DirectedEdge	getSym()
Node	getToNode()
void	print(java.io.PrintStream out)
void	setEdge(Edge parentEdge)
void	setSym(DirectedEdge sym)
static java.util.List	toEdges(java.util.Collection dirEdges)

Methods inherited from class java.lang.Object

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

Field Detail

cga

protected static final com.vividsolutions.jts.algorithm.RobustCGAlgorithms cga

parentEdge

protected Edge parentEdge

from

protected Node from

to

protected Node to

p0

protected com.vividsolutions.jts.geom.Coordinate p0

p1

protected com.vividsolutions.jts.geom.Coordinate p1

sym

protected DirectedEdge sym

edgeDirection

protected boolean edgeDirection

quadrant

protected int quadrant

angle

protected double angle

Constructor Detail

DirectedEdge

public DirectedEdge(Node from,
                    Node to,
                    com.vividsolutions.jts.geom.Coordinate directionPt,
                    boolean edgeDirection)

Method Detail

toEdges

public static java.util.List toEdges(java.util.Collection dirEdges)

getEdge

public Edge getEdge()

setEdge

public void setEdge(Edge parentEdge)

getEdgeDirection

public boolean getEdgeDirection()

getFromNode

public Node getFromNode()

getToNode

public Node getToNode()

getAngle

public double getAngle()

Returns the starting angle of this DirectedEdge.

getSym

public DirectedEdge getSym()

setSym

public void setSym(DirectedEdge sym)

compareTo

public int compareTo(java.lang.Object obj)

Specified by:

compareTo in interface java.lang.Comparable

compareDirection

public int compareDirection(DirectedEdge e)

Implements the total order relation:

a has a greater angle with the positive x-axis than b

Using the obvious algorithm of simply computing the angle is not robust, since the angle calculation is obviously susceptible to roundoff. A robust algorithm is: - first compare the quadrant. If the quadrants are different, it it trivial to determine which vector is "greater". - if the vectors lie in the same quadrant, the computeOrientation function can be used to decide the relative orientation of the vectors.

print

public void print(java.io.PrintStream out)