Time for action – spawning enemies

1. Add the SpawnEnemy() method to the EnemyManager class:

   public void SpawnEnemy(int path)
   {
       Enemy thisEnemy = new Enemy(
           texture,
           pathWaypoints[path][0],
           initialFrame,
           frameCount);
       for (int x = 0; x < pathWaypoints[path].Count(); x++)
       {
           thisEnemy.AddWaypoint(pathWaypoints[path][x]);
       }
       Enemies.Add(thisEnemy);
   }

2. Add the SpawnWave() method to the EnemyManager class:

   public void SpawnWave(int waveType)
   {
       waveSpawns[waveType] +=
           rand.Next(MinShipsPerWave, MaxShipsPerWave + 1);
   }

3. Add the updateWaveSpawns() method to the EnemyManager class:

   private void updateWaveSpawns(GameTime gameTime)
   {
       shipSpawnTimer += (float)gameTime.ElapsedGameTime.TotalSeconds;
       if (shipSpawnTimer > shipSpawnWaitTime)
       {
           for (int x = waveSpawns.Count - 1; x >= 0; x--)
           {
               if (waveSpawns[x] > 0)
               {
                   waveSpawns[x]--;
                   SpawnEnemy(x);
    ...