Time for action – beginning the implementation of A*

1. Add a new class called PathFinder to the Robot Rampage project.

2. Add the following using directive to the top of the class file:

   using Microsoft.Xna.Framework;

3. Modify the class declaration to make the class static:

   static class PathFinder

4. Add declarations to the PathFinder class:

   #region Declarations
   private enum NodeStatus { Open, Closed };
   
   private static Dictionary<Vector2, NodeStatus> nodeStatus = 
       new Dictionary<Vector2, NodeStatus>();
   
   private const int CostStraight = 10;
   private const int CostDiagonal = 15;
   
   private static List<PathNode> openList = new List<PathNode>();
   
   private static Dictionary<Vector2, float> nodeCosts = 
       new Dictionary<Vector2, float>();
   #endregion

5. Create a region in the PathFinder class for helper methods:

   #region Helper Methods
   #endregion

6. Add the addNodeToOpenList() method to the Helper Methods region of the PathFinder class:

   static private void addNodeToOpenList(PathNode node...