PongFE/PongFE/Engines/ComputerControlEngine.cs

using Encompass;
using PongFE.Components;
using PongFE.Enums;
using PongFE.Messages;

namespace PongFE.Engines
{
    [Reads(
        typeof(ComputerControlComponent),
        typeof(PositionComponent),
        typeof(CanBeTrackedComponent)
    )]
    [Sends(typeof(PaddleMoveMessage))]
    public class ComputerControlEngine : Engine
    {
        public override void Update(double dt)
        {
            foreach (ref readonly var entity in ReadEntities<ComputerControlComponent>())
            {
                if (HasComponent<PositionComponent>(entity))
                {
                    ref readonly var trackerPositionComponent = ref GetComponent<PositionComponent>(entity);

                    if (SomeComponent<CanBeTrackedComponent>())
                    {
                        ref readonly var trackedEntity = ref ReadEntity<CanBeTrackedComponent>();

                        if (HasComponent<PositionComponent>(trackedEntity))
                        {
                            ref readonly var trackedPositionComponent = ref GetComponent<PositionComponent>(trackedEntity);

                            if (trackerPositionComponent.Position.Y - trackedPositionComponent.Position.Y > 20)
                            {
                                SendMessage(new PaddleMoveMessage(entity, PaddleMoveDirection.Up));
                            }
                            else if (trackerPositionComponent.Position.Y - trackedPositionComponent.Position.Y < -20)
                            {
                                SendMessage(new PaddleMoveMessage(entity, PaddleMoveDirection.Down));
                            }
                        }
                    }
                }
            }
        }
    }
}