2 files changed, 17 insertions, 7 deletions

diff --git a/src/main/java/fr/umlv/java/wallj/board/PathFinder.java b/src/main/java/fr/umlv/java/wallj/board/PathFinder.java
index 9c509f3..8dbab2d 100644
--- a/src/main/java/fr/umlv/java/wallj/board/PathFinder.java
+++ b/src/main/java/fr/umlv/java/wallj/board/PathFinder.java
@@ -12,11 +12,6 @@ import java.util.stream.Collectors;
 public class PathFinder {
 
   private static final int LEAP_COST = 1;
-  private static final List<TileVec2> NEIGHBOR_OFFSETS = Arrays.asList(
-  TileVec2.of(0, -1),
-  TileVec2.of(-1, 0),
-  TileVec2.of(0, 1),
-  TileVec2.of(1, 0));
 
   private static class Node<T> {
     final T val;
@@ -99,8 +94,8 @@ public class PathFinder {
                                         .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
 
     for (Node<TileVec2> node : map.values())
-      NEIGHBOR_OFFSETS.stream()
-      .map(offsetVector -> map.get(node.val.add(offsetVector)))
+      node.val.neighbors().stream()
+      .map(map::get)
       .filter(Objects::nonNull)
       .forEach(neighbor -> node.neighbors.put(neighbor, LEAP_COST));
 
diff --git a/src/main/java/fr/umlv/java/wallj/board/TileVec2.java b/src/main/java/fr/umlv/java/wallj/board/TileVec2.java
index 70beed9..82200a7 100644
--- a/src/main/java/fr/umlv/java/wallj/board/TileVec2.java
+++ b/src/main/java/fr/umlv/java/wallj/board/TileVec2.java
@@ -2,7 +2,10 @@ package fr.umlv.java.wallj.board;
 
 import org.jbox2d.common.Vec2;
 
+import java.util.Arrays;
+import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 /**
  * A typed immutable tile coordinate vector containing the coordinates of a Tile in a Board.
@@ -12,6 +15,11 @@ import java.util.Objects;
 public final class TileVec2 {
 
   private static final int TILE_DIM = 20;
+  private static final List<TileVec2> NEIGHBOR_OFFSETS = Arrays.asList(
+  of(0, -1),
+  of(-1, 0),
+  of(0, 1),
+  of(1, 0));
 
   /**
    * @param col the column
@@ -62,6 +70,13 @@ public final class TileVec2 {
     return TileVec2.of(col + v.col, row + v.row);
   }
 
+  /**
+   * @return a list of the surrounding direct neighbours of this tile
+   */
+  public List<TileVec2> neighbors() {
+    return NEIGHBOR_OFFSETS.stream().map(this::add).collect(Collectors.toList());
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) return true;