KavTest/KavTest/Engines/RotationEngine.cs

using Encompass;
using KavTest.Components;
using Microsoft.Xna.Framework;

namespace KavTest.Engines
{
    [Reads(typeof(Transform3DComponent), typeof(AngularVelocityComponent))]
    [Writes(typeof(Transform3DComponent))]
    public class RotationEngine : Engine
    {
        public override void Update(double dt)
        {
            foreach (var entity in ReadEntities<AngularVelocityComponent>())
            {
                if (HasComponent<Transform3DComponent>(entity))
                {
                    ref readonly var angularVelocityComponent = ref GetComponent<AngularVelocityComponent>(entity);
                    ref readonly var transformComponent = ref GetComponent<Transform3DComponent>(entity);

                    var angularVelocity = angularVelocityComponent.AngularVelocity * (float)dt;

                    SetComponent(entity, new Transform3DComponent(transformComponent.Transform.Rotate(angularVelocity)));
                }
            }
        }
    }
}