Time for action – creating the EnemyManager class

1. Add a new class to the AsteroidBeltAssault project called EnemyManager.

2. Add the standard using directives to the top of the file:

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

3. Add declarations to the EnemyManager class:

   private Texture2D texture;
   private Rectangle initialFrame;
   private int frameCount;
   
   public List<Enemy> Enemies = new List<Enemy>();
   
   public ShotManager EnemyShotManager;
   private PlayerManager playerManager;
   
   public int MinShipsPerWave = 5;
   public int MaxShipsPerWave = 8;
   private float nextWaveTimer = 0.0f;
   private float nextWaveMinTimer = 8.0f;
   private float shipSpawnTimer = 0.0f;
   private float shipSpawnWaitTime = 0.5f;
   
   private float shipShotChance = 0.2f;
   
   private List<List<Vector2>> pathWaypoints = 
       new List<List<Vector2>>();
   
   private Dictionary<int, int> waveSpawns = new Dictionary<int, int>();public bool Active = true;
   
   private Random rand = new...