ManhattanHeuristic.java

package stray.pathfinding.heuristics;

import stray.pathfinding.AStarHeuristic;
import stray.pathfinding.Mover;
import stray.pathfinding.TileBasedMap;

/**
 * A heuristic that drives the search based on the Manhattan distance between
 * the current location and the target
 * 
 * @author Kevin Glass
 */
public class ManhattanHeuristic implements AStarHeuristic {

	/** The minimum movement cost from any one square to the next */
	private int minimumCost;

	/**
	 * Create a new heuristic
	 * 
	 * @param minimumCost
	 *            The minimum movement cost from any one square to the next
	 */
	public ManhattanHeuristic(int minimumCost) {
		this.minimumCost = minimumCost;
	}

	/**
	 * @see AStarHeuristic#getCost(TileBasedMap, Mover, int, int, int, int)
	 */
	public float getCost(TileBasedMap map, Mover mover, int x, int y, int tx, int ty) {
		return minimumCost * (Math.abs(x - tx) + Math.abs(y - ty));
	}

}