Time for action – the enemy manager

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

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

   using Microsoft.Xna.Framework;
   using Microsoft.Xna.Framework.Graphics;

3. Modify the declaration of the class to make it a static class:

   static class EnemyManager

4. Add declarations to the EnemyManager class:

   #region Declarations
   public static List<Enemy> Enemies = new List<Enemy>();
   public static Texture2D enemyTexture;
   public static Rectangle enemyInitialFrame;
   public static int MaxActiveEnemies = 30;
   #endregion

5. Add the Initialize() method to the EnemyManager class:

   #region Initialization
   public static void Initialize(
       Texture2D texture,
       Rectangle initialFrame)
   {
       enemyTexture = texture;
       enemyInitialFrame = initialFrame;
   }
   #endregion

6. Add the AddEnemy() method to the EnemyManager class:

   #region Enemy Management
   public static void AddEnemy(Vector2 squareLocation)
   {
       int startX = (int)squareLocation.X;
       int...