Implements IDamageArea

Introduction

The IDamageArea interface creates a standard way to define that an entity can deal damage to other entities. It has built-in support for teams and damage over time.

Setting Implements IDamageArea

To set an entity as a damage area, set the property on entity in the Properties tab.

A game which has entities implementing IDamageArea will also need entities which implement IDamageable.

Example - Damaging Enemies with Bullets

For this example uses two entities:

1. Bullet - an entity which implements IDamageArea and is ICollidable

2. Enemy - an entity which implements IDamageable and is ICollidable

The GameScreen also has a list for each and a collision relationship with an event.

When the bullet and enemy collide, the ShouldTakeDamage method can be used to determine if the enemy should take damage from the bullet, as shown in the following code snippet.

void OnEnemyListVsBulletListCollisionOccurred (Entities.Enemy enemy, Entities.Bullet bullet)
{
    if(enemy.ShouldTakeDamage(bullet))
    {
        enemy.TakeDamage(bullet.DamageAmount);
    }
}

The ShouldTakeDamage method is available on the Enemy since it implements the IDamageable interface, but the enemy.TakeDamage and bullet.DamageAmount are not provided automatically and must be implemented in custom code.

DamageDealer

The IDamageArea interface includes a DamageDealer property which can be used to store a reference to the damage dealer. This is typically used if the damage area is created by another entity, and that entity needs to be referenced upon collision. For example, in a multi-player game, each player may have a separate score. If an enemy is killed by a bullet, then the player who fired that bullet should be awarded points. For example, the following code could be used to assign the DamageDealer on a bullet created inside the Player class:

if(WasShootPressed)
{
  var bullet = Factories.BulletFactory.CreateNew(this.X, this.Y);
  bullet.XVelocity = 100;
  bullet.DamageDealer = this;
}