X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Fcarfire;a=blobdiff_plain;f=CarFire%2FCarFire%2FCarFire%2FPathFinder.cs;h=02c645cc8f8ed4c71e20705b96951a627acd15b4;hp=91724384ab2ac4cccca98b2c830b66c0bff2c1e7;hb=188525be158d8ba27fbbedf699eec5df59c5a2ee;hpb=681f16a95c1c67bdd40ed16842a70f8e10ba31e1

diff --git a/CarFire/CarFire/CarFire/PathFinder.cs b/CarFire/CarFire/CarFire/PathFinder.cs
index 9172438..02c645c 100644
--- a/CarFire/CarFire/CarFire/PathFinder.cs
+++ b/CarFire/CarFire/CarFire/PathFinder.cs
@@ -1,4 +1,8 @@
-using System;
+
+// Uncomment this to disable diagonal movemet.
+//#define ALLOW_DIAGONAL_MOVEMENT
+
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
@@ -125,7 +129,7 @@ namespace CarFire
                     List<Point> list = new List<Point>();
 
                     cell = cell.Parent;
-                    while (cell.Point != start)
+                    while (cell != null && cell.Point != start)
                     {
                         list.Add(cell.Point);
                         cell = cell.Parent;
@@ -136,23 +140,24 @@ namespace CarFire
                 }
 
                 List<Point> neighbors = new List<Point>(8);
+                neighbors.Add(new Point(cell.Point.X, cell.Point.Y - 1));
+                neighbors.Add(new Point(cell.Point.X - 1, cell.Point.Y));
+                neighbors.Add(new Point(cell.Point.X + 1, cell.Point.Y));
+                neighbors.Add(new Point(cell.Point.X, cell.Point.Y + 1));
+#if ALLOW_DIAGONAL_MOVEMENT
                 neighbors.Add(new Point(cell.Point.X - 1, cell.Point.Y - 1));
-                neighbors.Add(new Point(cell.Point.X + 0, cell.Point.Y - 1));
                 neighbors.Add(new Point(cell.Point.X + 1, cell.Point.Y - 1));
-                neighbors.Add(new Point(cell.Point.X - 1, cell.Point.Y + 0));
-                neighbors.Add(new Point(cell.Point.X + 1, cell.Point.Y + 0));
                 neighbors.Add(new Point(cell.Point.X - 1, cell.Point.Y + 1));
-                neighbors.Add(new Point(cell.Point.X + 0, cell.Point.Y + 1));
                 neighbors.Add(new Point(cell.Point.X + 1, cell.Point.Y + 1));
+#endif
                 foreach (Point point in neighbors)
                 {
-                    Cell inQueue = mCells[point.X, point.Y];
-
                     if (0 <= point.X && point.X < mGridWidth && 0 <= point.Y && point.Y < mGridHeight &&
                         mGrid[point.X, point.Y])
                     {
                         int cost = cell.G + costFunction(cell.Point, point);
 
+                        Cell inQueue = mCells[point.X, point.Y];
                         if (inQueue == null)
                         {
                             Cell neighbor = new Cell(point, cost, heuristic(point, finish), cell);