Projectile

Module for projectiles.

Currently Available Projectiles

• Fireball - Has a health component, is dealt as much damage as it deals.
• Spear - Can be picked up after use
• Grenade

Documentation

The ProjectileActionComponent is attached to any entity that is meant to be thrown when activated (mouse right-click) and that carries out an action after collision. The collision fires an HitTargetEvent which contains the following properties,

• instigator
• target
• origin
• direction
• hitPosition
• hitNormal

which is intercepted in a CollisionHandler that you can provide specifying custom behaviour on collision. The logic in the default CollisionHandler is as follows

public class ProjectileCollisionHandler extends BaseComponentSystem {
    // Set handler to low priority as it contains override-able default behaviour
    @Priority(EventPriority.PRIORITY_LOW)
    @ReceiveEvent
    public void onCollision(HitTargetEvent event, EntityRef entity, ProjectileActionComponent projectile) {
	    // inflict damage on target
        event.getTarget().send(new DoDamageEvent(projectile.damageAmount, projectile.damageType));
        //reset ProjectileActionComponent to defaults and drop item
        projectile.direction = null;
        projectile.currentVelocity = null;
        projectile.distanceTravelled = 0;
        entity.saveComponent(projectile);
        entity.send(new DropItemEvent(entity.getComponent(LocationComponent.class).getWorldPosition()));
    }
}

Projectiles are further customised by their prefabs. The various settings and defaults in ProjectileActionComponent can be found here.