Oyyou.MonoGameTutorials/MonoGame_Tutorials/Tutorial020/Sprites/Bullet.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework;

namespace Tutorial020.Sprites
{
  public class Bullet : Sprite, ICollidable
  {
    private float _timer;

    public Explosion Explosion;

    public float LifeSpan { get; set; }

    public Vector2 Velocity { get; set; }

    public Bullet(Texture2D texture)
      : base(texture)
    {

    }

    public override void Update(GameTime gameTime)
    {
      _timer += (float)gameTime.ElapsedGameTime.TotalSeconds;

      if (_timer >= LifeSpan)
        IsRemoved = true;

      Position += Velocity;
    }

    public void OnCollide(Sprite sprite)
    {
      //switch (sprite)
      //{
      //  case Bullet b:
      //    return;
      //  case Enemy e1 when e1.Parent is Enemy:

      //    if (e1.Parent is Enemy)
      //      return;

      //    if()

      //    return;
      //  case Enemy e2 when 

      //  case Player p when (p.IsDead || p.Parent is Player):
      //    return;
      //}

      // Bullets don't collide with eachother
      if (sprite is Bullet)
        return;

      // Enemies can't shoot eachother
      if (sprite is Enemy && this.Parent is Enemy)
        return;

      // Players can't shoot eachother
      if (sprite is Player && this.Parent is Player)
        return;

      // Can't hit a player if they're dead
      if (sprite is Player && ((Player)sprite).IsDead)
        return;

      if (sprite is Enemy && this.Parent is Player)
      {
        IsRemoved = true;
        AddExplosion();
      }

      if(sprite is Player && this.Parent is Enemy)
      {
        IsRemoved = true;
        AddExplosion();
      }
    }

    private void AddExplosion()
    {
      if (Explosion == null)
        return;

      var explosion = Explosion.Clone() as Explosion;
      explosion.Position = this.Position;

      Children.Add(explosion);
    }
  }
}