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Game.Objects.SpawnLocationConnectionSystem

Assembly:
Namespace: Game.Objects

Type: class

Base: GameSystemBase

Summary:
SpawnLocationConnectionSystem is a Unity ECS system used by Cities: Skylines 2 to maintain and update SpawnLocation components for in-game objects (buildings/objects that spawn vehicles/agents). It listens for changes in the world (updated nets, lots, spaces and SpawnLocation updates) and schedules Burst-compiled jobs that search nearby nets, areas and airways to find the best lane(s) and curve positions to connect a spawn location to the traffic network. The system uses quad-trees, parallel native collections and command buffers to perform high-performance, multi-threaded updates and mark entities that require pathfinding updates.

Fields

  • private Game.Net.SearchSystem m_NetSearchSystem
    Reference to the net search system used to query net quadtrees (roads/tracks) for lanes to connect spawn locations.

  • private Game.Net.UpdateCollectSystem m_NetUpdateCollectSystem
    Reference to the net update collector; used to check whether nets have been updated and to obtain updated net bounds.

  • private AirwaySystem m_AirwaySystem
    Reference to the airway system used for airplane/helicopter lane lookups for air-type spawn connections.

  • private Game.Areas.SearchSystem m_AreaSearchSystem
    Reference to the area search system used to find lots/spaces and area triangles relevant to spawn connection searches.

  • private Game.Areas.UpdateCollectSystem m_AreaUpdateCollectSystem
    Reference to the area update collector; used to check whether lots/spaces have been updated and to obtain updated bounds.

  • private SearchSystem m_ObjectSearchSystem
    Reference to the global object search tree used to find nearby spawn locations when nets/areas/lots change.

  • private ModificationBarrier5 m_ModificationBarrier
    Modification barrier used to obtain a parallel command buffer writer for making structural changes (adding PathfindUpdated, removing/setting components) safely from jobs.

  • private EntityQuery m_UpdatedQuery
    EntityQuery that detects SpawnLocation entities flagged with Updated or RoadConnectionUpdated events so they can be re-evaluated.

  • private TypeHandle __TypeHandle
    Internal container for ComponentLookup/TypeHandle/BufferLookup instances the system assigns once during setup to be used when scheduling jobs.

Properties

  • None (this system exposes no public properties)

Constructors

  • public SpawnLocationConnectionSystem()
    Default constructor. The system is attributed with Preserve and the real initialization occurs in OnCreate.

Methods

  • protected override void OnCreate()
    Initializes references to other world systems (net/area/airway search and update-collect systems, object search system and modification barrier). It also builds the EntityQuery used to detect spawn locations that require re-evaluation. This method wires up the TypeHandle assignment path used later by jobs.

  • protected override void OnUpdate()
    Main update loop. Checks whether any relevant updates occurred (net/lot/space updates or SpawnLocation update events). If updates exist it:

  • Allocates temporary native queues & list (per-job-safe collections) to gather updated spawn location entities.
  • Schedules FindUpdatedSpawnLocationsJob instances to query the object search tree for SpawnLocation entities within updated bounds (nets/lots/spaces).
  • Optionally schedules CheckUpdatedSpawnLocationsJob to gather spawn locations from RoadConnectionUpdated events.
  • Runs ListUpdatedSpawnLocationsJob to merge and de-duplicate those queues into a sorted NativeList.
  • Schedules FindSpawnLocationConnectionJob (Burst, parallel) over the list of updated entities to compute the best lane connections and curve positions. That job:
    • Looks up prefab spawn configuration (SpawnLocationData).
    • Handles air connections via AirwayData maps.
    • Uses net/area/attached/owner fallbacks to find best lane(s).
    • Applies connection-type checks (road/track/pedestrian/air) and respects activity masks and route connection rules.
    • Writes updates to SpawnLocation components via a parallel EntityCommandBuffer and adds PathfindUpdated when a spawn location changed.

  • Manages job dependencies and registers readers with the appropriate search/update systems; disposes temporary native containers once jobs are scheduled.

  • protected override void OnCreateForCompiler()
    Internal helper called during codegen/compilation for system initialization. Calls __AssignQueries and assigns Component/Buffer/Type handles via __TypeHandle.

  • private void __AssignQueries(ref SystemState state)
    Compiler-generated helper that sets up any EntityQueryBuilder usage and is used by OnCreateForCompiler. It is essentially a placeholder for query assignments done at compile-time.

  • (nested types and jobs) FindUpdatedSpawnLocationsJob, CheckUpdatedSpawnLocationsJob, ListUpdatedSpawnLocationsJob, FindSpawnLocationConnectionJob and several iterator/helper structs.
    These nested Burst-compiled jobs perform the heavy work:

  • FindUpdatedSpawnLocationsJob: iterates a NativeList (deferred) and queries the object search quadtree in parallel to enqueue any SpawnLocation entities intersecting expanded bounds.
  • CheckUpdatedSpawnLocationsJob: chunk-based job that inspects entities with RoadConnectionUpdated or the Updated query and enqueues relevant spawn locations.
  • ListUpdatedSpawnLocationsJob: merges up to four native queues into a single NativeList, sorts and de-duplicates the list (stable, by entity index) for parallel processing.
  • FindSpawnLocationConnectionJob: for each spawn location entity, inspects prefab data, attached/owner/building fallbacks, searches nearby net quadtrees and area quadtrees and airway maps, determines best connection lanes and curve positions, and updates SpawnLocation components (and adds PathfindUpdated) via a parallel command buffer.

Notes about the jobs: - All heavy jobs are Burst-compiled and use NativeQuadTree iteration or area triangle distance checks for accuracy and speed. - Jobs use NativeQueue/NativeList deferred arrays and are scheduled with proper dependency chaining and external readers registered in the various systems to maintain correct concurrency. - The FindSpawnLocationConnectionJob contains multiple lane-type checks and logic for pairing car lanes into opposite-direction pairs where applicable (m_ConnectedLane1/m_ConnectedLane2).

Usage Example

// Systems are created and managed by the World. You can get a reference to this system from your mod code:
var spawnConnSystem = World.DefaultGameObjectInjectionWorld.GetExistingSystemManaged<Game.Objects.SpawnLocationConnectionSystem>();

// The system runs automatically each frame. If you need to force a single update (rare), you can call:
spawnConnSystem.Update(); // not commonly needed — use carefully in mod context

// Example: inside a custom system you can query SpawnLocation components or listen for PathfindUpdated
// to react when the SpawnLocationConnectionSystem marks an entity for pathfind recalculation.

Additional tips for modders: - If you add custom spawn-related prefabs, supply a proper SpawnLocationData and RouteConnectionData so this system can find and respect the desired connection type and activity masks. - When interacting with spawn locations from jobs, be mindful that this system uses ModificationBarrier5 to make structural changes; use the same barrier or a compatible approach to avoid race conditions. - The system uses distance thresholds and clamps for curve positions; when creating custom net geometries, ensure curves and lane flags match the expected ConnectionLane/LaneFlags to be discovered correctly.