openlr.map.utils
Class NodeCheck

java.lang.Object
  openlr.map.utils.NodeCheck

public final class NodeCheck
extends Object

The Class NodeCheck checks the validity of a node. A node is invalid if it is not possible to leave a path at this node (no start of a deviation possible).

OpenLR is a trade mark of TomTom International B.V.

email: software@openlr.org

Author:

TomTom International B.V.

Method Summary

static boolean	isPair(Line line1, Line line2) Checks if line1 and line2 connect only two nodes and point into two different directions.
static boolean	isValidNode(Node n) Checks if node n is valid.

Methods inherited from class java.lang.Object

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

Method Detail

isValidNode

public static boolean isValidNode(Node n)

Checks if node n is valid. The method distinguishes two cases for a node being invalid.

• the node has a degree of 2 and it is not a dead-end street
  • if a node has only one incoming and one outgoing line then it can be skipped during route search because no deviation at this point is possible
  • if the node is part of a dead-end street, then the node is still valid because otherwise at this point it is only possible to go back the line
  • if such a dead-end node is start or end of a location it needs to be valid, otherwise every extension might be useless
• the node has a degree of 4 and the incoming/outgoing lines are pairwise
  • if the incoming/outgoing lines form two pairs, then the node connects only two other nodes and no deviation is possible (u-turns are also not allowed)
  • if there are more connected lines, then the node is valid

Parameters:

n - the node

Returns:

true, if node n is valid, otherwise false

isPair

public static boolean isPair(Line line1,
                             Line line2)

Checks if line1 and line2 connect only two nodes and point into two different directions. So one line is the opposite direction of the other one.

Parameters:

line1 - the first line

line2 - the second line

Returns:

true, if the lines have start/end nodes in common and define two different directions