DirectedEdge

java.lang.Object
- com.vividsolutions.jts.planargraph.GraphComponent
- - com.vividsolutions.jts.planargraph.DirectedEdge

All Implemented Interfaces:

Comparable

Direct Known Subclasses:

LineMergeDirectedEdge
```
public class DirectedEdge
extends GraphComponent
implements Comparable
```
Represents a directed edge in a PlanarGraph. A DirectedEdge may or may not have a reference to a parent Edge (some applications of planar graphs may not require explicit Edge objects to be created). Usually a client using a PlanarGraph will subclass DirectedEdge to add its own application-specific data and methods.

Field Summary

Fields

Modifier and Type	Field and Description
`protected double`	`angle`
`protected boolean`	`edgeDirection`
`protected Node`	`from`
`protected Coordinate`	`p0`
`protected Coordinate`	`p1`
`protected Edge`	`parentEdge`
`protected int`	`quadrant`
`protected DirectedEdge`	`sym`
`protected Node`	`to`

Fields inherited from class com.vividsolutions.jts.planargraph.GraphComponent
isMarked, isVisited

Constructor Summary

Constructors

Constructor and Description
`DirectedEdge(Node from, Node to, Coordinate directionPt, boolean edgeDirection)` Constructs a DirectedEdge connecting the `from` node to the `to` node.

Method Summary

All Methods

Static Methods

Instance Methods

Concrete Methods
Modifier and Type	Method and Description
`int`	`compareDirection(DirectedEdge e)` Returns 1 if this DirectedEdge has a greater angle with the positive x-axis than b", 0 if the DirectedEdges are collinear, and -1 otherwise.
`int`	`compareTo(Object obj)` Returns 1 if this DirectedEdge has a greater angle with the positive x-axis than b", 0 if the DirectedEdges are collinear, and -1 otherwise.
`double`	`getAngle()` Returns the angle that the start of this DirectedEdge makes with the positive x-axis, in radians.
`Coordinate`	`getCoordinate()` Returns the coordinate of the from-node.
`Coordinate`	`getDirectionPt()` Returns a point to which an imaginary line is drawn from the from-node to specify this DirectedEdge's orientation.
`Edge`	`getEdge()` Returns this DirectedEdge's parent Edge, or null if it has none.
`boolean`	`getEdgeDirection()` Returns whether the direction of the parent Edge (if any) is the same as that of this Directed Edge.
`Node`	`getFromNode()` Returns the node from which this DirectedEdge leaves.
`int`	`getQuadrant()` Returns 0, 1, 2, or 3, indicating the quadrant in which this DirectedEdge's orientation lies.
`DirectedEdge`	`getSym()` Returns the symmetric DirectedEdge -- the other DirectedEdge associated with this DirectedEdge's parent Edge.
`Node`	`getToNode()` Returns the node to which this DirectedEdge goes.
`boolean`	`isRemoved()` Tests whether this directed edge has been removed from its containing graph
`void`	`print(PrintStream out)` Prints a detailed string representation of this DirectedEdge to the given PrintStream.
`void`	`setEdge(Edge parentEdge)` Associates this DirectedEdge with an Edge (possibly null, indicating no associated Edge).
`void`	`setSym(DirectedEdge sym)` Sets this DirectedEdge's symmetric DirectedEdge, which runs in the opposite direction.
`static List`	`toEdges(Collection dirEdges)` Returns a List containing the parent Edge (possibly null) for each of the given DirectedEdges.

Methods inherited from class com.vividsolutions.jts.planargraph.GraphComponent
getComponentWithVisitedState, getContext, getData, isMarked, isVisited, setContext, setData, setMarked, setMarked, setVisited, setVisited

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - parentEdge
```
protected Edge parentEdge
```
  - from
```
protected Node from
```
  - to
```
protected Node to
```
  - p0
```
protected Coordinate p0
```
  - p1
```
protected 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,
                    Coordinate directionPt,
                    boolean edgeDirection)
```
    Constructs a DirectedEdge connecting the from node to the to node.
    
    Parameters:
    
    directionPt - specifies this DirectedEdge's direction vector (determined by the vector from the from node to directionPt)
    
    edgeDirection - whether this DirectedEdge's direction is the same as or opposite to that of the parent Edge (if any)
- Method Detail
  - toEdges
```
public static List toEdges(Collection dirEdges)
```
    Returns a List containing the parent Edge (possibly null) for each of the given DirectedEdges.
  - getEdge
```
public Edge getEdge()
```
    Returns this DirectedEdge's parent Edge, or null if it has none.
  - setEdge
```
public void setEdge(Edge parentEdge)
```
    Associates this DirectedEdge with an Edge (possibly null, indicating no associated Edge).
  - getQuadrant
```
public int getQuadrant()
```
    Returns 0, 1, 2, or 3, indicating the quadrant in which this DirectedEdge's orientation lies.
  - getDirectionPt
```
public Coordinate getDirectionPt()
```
    Returns a point to which an imaginary line is drawn from the from-node to specify this DirectedEdge's orientation.
  - getEdgeDirection
```
public boolean getEdgeDirection()
```
    Returns whether the direction of the parent Edge (if any) is the same as that of this Directed Edge.
  - getFromNode
```
public Node getFromNode()
```
    Returns the node from which this DirectedEdge leaves.
  - getToNode
```
public Node getToNode()
```
    Returns the node to which this DirectedEdge goes.
  - getCoordinate
```
public Coordinate getCoordinate()
```
    Returns the coordinate of the from-node.
  - getAngle
```
public double getAngle()
```
    Returns the angle that the start of this DirectedEdge makes with the positive x-axis, in radians.
  - getSym
```
public DirectedEdge getSym()
```
    Returns the symmetric DirectedEdge -- the other DirectedEdge associated with this DirectedEdge's parent Edge.
  - setSym
```
public void setSym(DirectedEdge sym)
```
    Sets this DirectedEdge's symmetric DirectedEdge, which runs in the opposite direction.
  - isRemoved
```
public boolean isRemoved()
```
    Tests whether this directed edge has been removed from its containing graph
    
    Specified by:
    
    isRemoved in class GraphComponent
    
    Returns:
    
    true if this directed edge is removed
  - compareTo
```
public int compareTo(Object obj)
```
    Returns 1 if this DirectedEdge has a greater angle with the positive x-axis than b", 0 if the DirectedEdges are collinear, and -1 otherwise.
    Using the obvious algorithm of simply computing the angle is not robust, since the angle calculation is susceptible to roundoff. A robust algorithm is:
    - first compare the quadrants. If the quadrants are different, it it trivial to determine which vector is "greater".
    - if the vectors lie in the same quadrant, the robust CGAlgorithms.computeOrientation(Coordinate, Coordinate, Coordinate) function can be used to decide the relative orientation of the vectors.
  - compareDirection
```
public int compareDirection(DirectedEdge e)
```
    Returns 1 if this DirectedEdge has a greater angle with the positive x-axis than b", 0 if the DirectedEdges are collinear, and -1 otherwise.
    Using the obvious algorithm of simply computing the angle is not robust, since the angle calculation is susceptible to roundoff. A robust algorithm is:
    - first compare the quadrants. If the quadrants are different, it it trivial to determine which vector is "greater".
    - if the vectors lie in the same quadrant, the robust CGAlgorithms.computeOrientation(Coordinate, Coordinate, Coordinate) function can be used to decide the relative orientation of the vectors.
  - print
```
public void print(PrintStream out)
```
    Prints a detailed string representation of this DirectedEdge to the given PrintStream.

Class DirectedEdge

Field Summary

Fields

Fields inherited from class com.vividsolutions.jts.planargraph.GraphComponent

Constructor Summary

Constructors

Method Summary

Methods inherited from class com.vividsolutions.jts.planargraph.GraphComponent

Methods inherited from class java.lang.Object

Field Detail

parentEdge

from

to

p0

p1

sym

edgeDirection

quadrant

angle

Constructor Detail

DirectedEdge

Method Detail

toEdges

getEdge

setEdge

getQuadrant

getDirectionPt

getEdgeDirection

getFromNode

getToNode

getCoordinate

getAngle

getSym

setSym

isRemoved

compareTo

compareDirection

print