Online and offline

X-Ray keeps two related views of many objects:

• a server-side ALife object, which can exist while the object is offline;
• a client-side game object, which exists when the object is online and active on the current level.

Online/offline state is not the same as alive/dead. An offline object can still exist in simulation. An online object has a live game_object, a binder, callbacks, and client-side updates.

Offline objects

Offline objects live in the ALife simulation. They are represented by server objects and can be queried through simulator APIs. Smart terrains, squads, NPCs, monsters, items, and level changers all have server-side behavior in different ways.

Use server objects for simulation state, spawn data, story ids, smart terrain membership, and logic that must survive outside the active client bubble.

Online objects

When an object switches online, the engine creates or activates a client-side game_object and attaches an object_binder. XRF uses binders to register object state, set callbacks, emit events, and update active schemes.

Use online objects for:

• direct game object methods;
• visible object state;
• callbacks such as hit, death, use, inventory, or task updates;
• per-frame or throttled client-side updates.

Do not assume level.object_by_id(id) succeeds for an offline object. Use the simulator/server object path when the object may be offline.

Switching

The engine decides when objects switch online or offline based on ALife rules, level state, distance, and object type. Console variables such as al_switch_distance, al_objects_per_update, and related ALife settings affect this process.

XRF binders receive net_spawn(...) when an object goes online and net_destroy() when it goes offline or is destroyed. Put registration and callback setup in the online path, and cleanup in the offline path.