Fixed path finder thrown exception when finding a path to the cell you are already at.

[chaz/carfire] / CarFire / CarFire / CarFire / PathFinder.cs

diff --git a/CarFire/CarFire/CarFire/PathFinder.cs b/CarFire/CarFire/CarFire/PathFinder.cs
index 91724384ab2ac4cccca98b2c830b66c0bff2c1e7..c37e51863d7ad4b4abe9b18c707de8a8126fcaf8 100644 (file)
--- a/CarFire/CarFire/CarFire/PathFinder.cs
+++ b/CarFire/CarFire/CarFire/PathFinder.cs
@@ -1,4 +1,8 @@
-using System;\r
+\r
+// Uncomment this to disable diagonal movemet.\r
+//#define ALLOW_DIAGONAL_MOVEMENT\r
+\r
+using System;\r
 using System.Collections.Generic;\r
 using System.Linq;\r
 using System.Text;\r
@@ -125,7 +129,7 @@ namespace CarFire
                     List<Point> list = new List<Point>();\r
 \r
                     cell = cell.Parent;\r
-                    while (cell.Point != start)\r
+                    while (cell != null && cell.Point != start)\r
                     {\r
                         list.Add(cell.Point);\r
                         cell = cell.Parent;\r
@@ -136,14 +140,16 @@ namespace CarFire
                 }\r
 \r
                 List<Point> neighbors = new List<Point>(8);\r
+                neighbors.Add(new Point(cell.Point.X, cell.Point.Y - 1));\r
+                neighbors.Add(new Point(cell.Point.X - 1, cell.Point.Y));\r
+                neighbors.Add(new Point(cell.Point.X + 1, cell.Point.Y));\r
+                neighbors.Add(new Point(cell.Point.X, cell.Point.Y + 1));\r
+#if ALLOW_DIAGONAL_MOVEMENT\r
                 neighbors.Add(new Point(cell.Point.X - 1, cell.Point.Y - 1));\r
-                neighbors.Add(new Point(cell.Point.X + 0, cell.Point.Y - 1));\r
                 neighbors.Add(new Point(cell.Point.X + 1, cell.Point.Y - 1));\r
-                neighbors.Add(new Point(cell.Point.X - 1, cell.Point.Y + 0));\r
-                neighbors.Add(new Point(cell.Point.X + 1, cell.Point.Y + 0));\r
                 neighbors.Add(new Point(cell.Point.X - 1, cell.Point.Y + 1));\r
-                neighbors.Add(new Point(cell.Point.X + 0, cell.Point.Y + 1));\r
                 neighbors.Add(new Point(cell.Point.X + 1, cell.Point.Y + 1));\r
+#endif\r
                 foreach (Point point in neighbors)\r
                 {\r
                     Cell inQueue = mCells[point.X, point.Y];\r