"Adding Reflection-Based Polymorphism, First Part"

public static class ComponentExtensions {
    private static readonly Dictionary<string, Dictionary<Type, MethodInfo>> overrides = new Dictionary<string, Dictionary<Type, MethodInfo>>();
     
    private static bool HasOverride(object targetObj, [CallerMemberName] string callerName = null) {
        if (!vtable.ContainsKey(callerName)) return false;
        var overridesForMember = overrides[callerName];
        var targetType = targetObj.GetType();
        return overridesForMember.ContainsKey(targetType);
    }
    private static T InvokeOverride<T>(object targetObj, object[] parameters, [CallerMemberName] string callerName = null) {
        var overridesForMember = overrides[callerName];
        var targetType = targetObj.GetType();
        return (T) overridesForMember[targetType].Invoke(targetObj, parameters);
    }
    private static void InvokeOverride(object targetObj, object[] parameters, [CallerMemberName] string callerName = null) {
        var overridesForMember = overrides[callerName];
        var targetType = targetObj.GetType();
        overridesForMember[targetType].Invoke(targetObj, parameters);
    }
 
    // ITangibleEntity
    public static Vector3 GetPosition(this ITangibleEntity @this) {
        if (HasOverride(@this)) {
            return InvokeOverride<Vector3>(@this, new object[] { });
        }
 
        return GetAdjunctField(@this, "ITangibleEntity.Position", () => Vector3.Zero);
    }
    public static void SetPosition(this ITangibleEntity @this, Vector3 newPosition) {
        if (HasOverride(@this)) {
            InvokeOverride(@this, new object[] { newPosition });
            return;
        }
 
        SetAdjunctField(@this, "ITangibleEntity.Position", newPosition);
    }
    public static Vector3 GetVelocity(this ITangibleEntity @this) {
        if (HasOverride(@this)) {
            return InvokeOverride<Vector3>(@this, new object[] { });
        }
 
        return GetAdjunctField(@this, "ITangibleEntity.Velocity", () => Vector3.Zero);
    }
    public static void SetVelocity(this ITangibleEntity @this, Vector3 newVelocity) {
        if (HasOverride(@this)) {
            InvokeOverride(@this, new object[] { newVelocity });
            return;
        }
 
        SetAdjunctField(@this, "ITangibleEntity.Velocity", newVelocity);
    }
}