private Enemy CreateEnemyFromDef(EnemyDef definition)
        {
            Enemy enemy = new Enemy(_textureManager, _effectsManager, _bulletManager);

            if (definition.EnemyType == "cannon_fodder")
            {
                List <Vector> _pathPoints = new List <Vector>();
                _pathPoints.Add(new Vector(1400, 0, 0));
                _pathPoints.Add(new Vector(0, 250, 0));
                _pathPoints.Add(new Vector(-1400, 0, 0));

                enemy.Path = new Path(_pathPoints, 10);
            }
            else if (definition.EnemyType == "cannon_fodder_low")
            {
                List <Vector> _pathPoints = new List <Vector>();
                _pathPoints.Add(new Vector(1400, 0, 0));
                _pathPoints.Add(new Vector(0, -250, 0));
                _pathPoints.Add(new Vector(-1400, 0, 0));

                enemy.Path = new Path(_pathPoints, 10);
            }
            else if (definition.EnemyType == "cannon_fodder_straight")
            {
                List <Vector> _pathPoints = new List <Vector>();
                _pathPoints.Add(new Vector(1400, 0, 0));
                _pathPoints.Add(new Vector(-1400, 0, 0));

                enemy.Path = new Path(_pathPoints, 14);
            }
            else if (definition.EnemyType == "up_l")
            {
                List <Vector> _pathPoints = new List <Vector>();
                _pathPoints.Add(new Vector(500, -375, 0));
                _pathPoints.Add(new Vector(500, 0, 0));
                _pathPoints.Add(new Vector(500, 0, 0));
                _pathPoints.Add(new Vector(-1400, 200, 0));

                enemy.Path = new Path(_pathPoints, 10);
            }
            else if (definition.EnemyType == "down_l")
            {
                List <Vector> _pathPoints = new List <Vector>();
                _pathPoints.Add(new Vector(500, 375, 0));
                _pathPoints.Add(new Vector(500, 0, 0));
                _pathPoints.Add(new Vector(500, 0, 0));
                _pathPoints.Add(new Vector(-1400, -200, 0));

                enemy.Path = new Path(_pathPoints, 10);
            }
            else
            {
                System.Diagnostics.Debug.Assert(false, "Unknown enemy type.");
            }

            return(enemy);
        }
        private void UpdateEnemySpawns(double gameTime)
        {
            // If no upcoming enemies then there's nothing to spawn.
            if (_upComingEnemies.Count == 0)
            {
                return;
            }

            EnemyDef lastElement = _upComingEnemies[_upComingEnemies.Count - 1];

            if (gameTime < lastElement.LaunchTime)
            {
                _upComingEnemies.RemoveAt(_upComingEnemies.Count - 1);
                _enemies.Add(CreateEnemyFromDef(lastElement));
            }
        }