Spatial

Mounts

A rideable STATE on an entity: mount id + opaque look blob + speed multiplier (applied through Movement's speed seam via a Hosting bridge). Horses, hoverboards, sprint stances, transformation forms — same state machine, the game's render. Ownership/eligibility = IMountPolicy; broadcast on change + replayed on interest reveal; empty catalog = inert.

Server: services.AddCrossplayMounts();
Unity package: com.crossplay.mounts
Depends on: world

Providers you can swap 1

Infrastructure seams. Crossplay ships a working implementation of each — replacing one changes where data lives or how it moves, never a game rule.

IMountPolicy provider

The game's mount rule: may THIS player ride THIS mount now? Ownership, unlocks, indoor bans, combat locks — the game's vocabulary; the default allows every configured mount. Register yours BEFORE AddCrossplayMounts (a TryAdd seam).

bool AllowMount(ISession session, long ownerId, ushort mountId, out ushort reasonCode)
True when riding is allowed. On refusal set reasonCode (0 falls back to MountRefused).

Services you call 1

Crossplay implements these. Resolve them from DI and call them from your own systems.

IMountService

Server-side Mounts API — what the wire handler calls, and what game code calls directly (dismount on combat entry, mount from a dialog action, force-dismount in a no-ride zone).

bool Dismount(long entityId)
Force-dismounts an entity server-side (no policy — the server is authoritative). True when the entity was mounted.
event Action<long, ushort> MountChanged
Raised after a COMMITTED state change with (entity id, mount id — 0 = dismounted).
bool TryGetMount(long entityId, out ushort mountId, out MountDefinition definition)
The entity's active mount, if it rides one (the speed bridge reads this per move).
bool TrySetMount(ISession session, ushort mountId, out ushort reasonCode)
Mounts (or, with id 0, dismounts) the session's entity: catalog gate → policy → state change → broadcast. Returns false with a code on refusal.

Configuration 1

Every tunable lives in an options object — there are no magic numbers to hunt for.

MountOptions

Configurable mount parameters (defaults here; never inlined in logic).

Dictionary<ushort, MountDefinition> Mounts { get; set; }
The mount catalog, keyed by game-defined mount id. Empty (the default) leaves the piece inert: every request answers UnknownMount.

Wire messages 3

The protocol this piece speaks. Ids are allocated per piece so they can never collide.

6001 MountRequest

Client → server: "I mount X" (0 = dismount). WHAT a mount is — a horse, a hoverboard, a sprint stance, a transformation — is 100% the game's; the piece knows a number and a look blob.

6002 MountResponse

Server → actor: the verdict. The state itself replicates via EntityMountChanged; the speed change rides the ordinary movement wire.

6003 EntityMountChanged

Server → observers + actor: the visible mount state. One game swaps in a horse model, another tints a sprite, another plays a sound — the piece cannot tell the difference.

Unity services you inject 1

Crossplay binds these in the client context. Inject and call them from your own MonoBehaviours and presenters.

IMountClient

The Mounts piece, client side: mount/dismount, and observe EVERY entity's rideable state (id + opaque look blob, broadcast on change and replayed on interest reveal). One game swaps in a horse model, another tints a sprite — bind EntityMountChanged to your entity views. The speed change rides the ordinary movement wire, never this piece.

void Mount(ushort mountId)
Ride mount X (the game's policy validates ownership/eligibility server-side).
void Dismount()
Dismount.
event Action<MountResponse> ResultReceived
The server's verdict on your mount/dismount.
event Action<EntityMountChanged> EntityMountChanged
An entity's mount state changed (or was revealed): render it.