de.rico.engine.path
Class AStarNode

java.lang.Object
  de.rico.engine.path.AStarNode

All Implemented Interfaces:

java.lang.Comparable

Direct Known Subclasses:

GridNode

public abstract class AStarNode
extends java.lang.Object
implements java.lang.Comparable

The AStarNode class, along with the AStarSearch class, implements a generic A* search algorthim. The AStarNode class should be subclassed to provide searching capability.

Author:

David Brackeen (Book: Developing Games in Java), minor additions by Frank Bruns

Constructor Summary

AStarNode()

Method Summary

int	compareTo(java.lang.Object other)
float	getCost() Returns the cost of the node
abstract float	getCost(AStarNode node) Gets the cost between this node and the specified adjacent (aka "neighbor" or "child") node.
abstract float	getEstimatedCost(AStarNode node) Gets the estimated cost between this node and the specified node.
abstract java.util.List	getNeighbors() Gets the children (aka "neighbors" or "adjacent nodes") of this node.
int	sign(float v) Returns the sign of the number.

Methods inherited from class java.lang.Object

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

Constructor Detail

AStarNode

public AStarNode()

Method Detail

getCost

public float getCost()

Returns the cost of the node

Returns:

cost of the node

compareTo

public int compareTo(java.lang.Object other)

Specified by:

compareTo in interface java.lang.Comparable

getCost

public abstract float getCost(AStarNode node)

Gets the cost between this node and the specified adjacent (aka "neighbor" or "child") node.

getEstimatedCost

public abstract float getEstimatedCost(AStarNode node)

Gets the estimated cost between this node and the specified node. The estimated cost should never exceed the true cost. The better the estimate, the more effecient the search.

getNeighbors

public abstract java.util.List getNeighbors()

Gets the children (aka "neighbors" or "adjacent nodes") of this node.

sign

public int sign(float v)

Returns the sign of the number. Returns -1 for negative, 1 for positive, and 0 otherwise.