Merge pull request #191 from apollo-rsps/bugfix/106-fix-astar-pathfinder

Fix the A* path finding implementation

game/src/main/org/apollo/game/model/entity/path/AStarPathfindingAlgorithm.java

@@ -9,6 +9,7 @@ import java.util.PriorityQueue;
 import java.util.Queue;
 import java.util.Set;
 
+import org.apollo.game.model.Direction;
 import org.apollo.game.model.Position;
 import org.apollo.game.model.area.RegionRepository;
 
@@ -73,7 +74,8 @@ public final class AStarPathfindingAlgorithm extends PathfindingAlgorithm {
 					}
 
 					Position adjacent = new Position(nextX, nextY);
-					if (traversable(adjacent)) {
+					Direction direction = Direction.between(adjacent, position);
+					if (traversable(adjacent, direction)) {
 						Node node = nodes.computeIfAbsent(adjacent, Node::new);
 						compare(active, node, open, sorted, heuristic);
 					}

game/src/main/org/apollo/game/model/entity/path/EuclideanHeuristic.java

@@ -0,0 +1,17 @@
+package org.apollo.game.model.entity.path;
+
+import org.apollo.game.model.Position;
+
+/**
+ * A heuristic which uses <i>Euclidean</i> distance to calculate the cost for a movement.
+ */
+public final class EuclideanHeuristic extends Heuristic {
+
+	/**
+	 * @see Position#getDistance(Position)
+	 */
+	@Override
+	public int estimate(Position current, Position target) {
+		return current.getDistance(target);
+	}
+}