tbd-station-14/Content.Shared/GameObjects/EntitySystems/ExamineSystemShared.cs

using Content.Shared.GameObjects.Components.Mobs;
using JetBrains.Annotations;
using Robust.Shared.GameObjects.Systems;
using Robust.Shared.Interfaces.GameObjects;

namespace Content.Shared.GameObjects.EntitySystems
{
    public abstract class ExamineSystemShared : EntitySystem
    {
        public const float ExamineRange = 8f;
        public const float ExamineRangeSquared = ExamineRange * ExamineRange;

        [Pure]
        protected static bool CanExamine(IEntity examiner, IEntity examined)
        {
            if (!examiner.TryGetComponent(out ExaminerComponent examinerComponent))
            {
                return false;
            }

            if (!examinerComponent.DoRangeCheck)
            {
                return true;
            }

            if (examiner.Transform.MapID != examined.Transform.MapID)
            {
                return false;
            }

            var delta = examined.Transform.WorldPosition - examiner.Transform.WorldPosition;
            return delta.LengthSquared <= ExamineRangeSquared;
        }
    }
}