Game.Simulation.GroundPollutionSystem
Assembly: Assembly-CSharp (in-game)
Namespace: Game.Simulation
Type: class
Base: CellMapSystem
Summary:
Manages the ground pollution cell map used by the simulation. This system holds a 256×256 cell texture of GroundPollution values, updates (fades) pollution over time using a Burst-compiled IJob, provides sampling helpers (including bilinear interpolation), and ties into the SimulationSystem frame index and PollutionParameterData singleton. The system schedules a PollutionFadeJob each update tick to reduce pollution values according to configured parameters and per-frame randomness.
Fields
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public static readonly int kTextureSize = 256
Defines the pollution texture width and height (map is kTextureSize × kTextureSize = 256×256 cells). Used by sampling and for creating the cell textures. -
public static readonly int kUpdatesPerDay = 128
Number of update steps per simulated day. Used in calculations for fade amount and to compute the update interval. -
private SimulationSystem m_SimulationSystem
Reference to the SimulationSystem instance (retrieved in OnCreate) used to read the current simulation frame index (m_SimulationSystem.frameIndex) for deterministic randomness in the job scheduling. -
private EntityQuery m_PollutionParameterGroup
EntityQuery used to obtain the PollutionParameterData singleton. The system requires this query for updates (RequireForUpdate is called). -
private struct PollutionFadeJob(private nested, Burst compiled)
A private nested IJob (annotated with [BurstCompile]) that performs the per-cell pollution fade. It contains: NativeArray<GroundPollution> m_PollutionMap— the cell map to mutate.PollutionParameterData m_PollutionParameters— parameters (e.g., m_GroundFade) driving fade amount.RandomSeed m_Random— seed provider used to create a Random instance per-frame for randomized rounding.uint m_Frame— frame index used to derive deterministic Random instance. The job iterates the map and reduces each cell's m_Pollution by a randomized rounded amount: RoundToIntRandom((float)m_GroundFade / kUpdatesPerDay), clamped to zero.
Properties
public int2 TextureSize => new int2(kTextureSize, kTextureSize)
Returns the cell map texture size as an int2 (256, 256). Useful when interacting with other systems that need the map resolution.
Constructors
public GroundPollutionSystem()
Default constructor. The system relies on OnCreate to perform initialization.
Methods
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public override int GetUpdateInterval(SystemUpdatePhase phase)
Returns the update interval for the system in simulation ticks: 262144 / kUpdatesPerDay. This controls how often the system is scheduled in a full simulation tick cycle relative to its updates-per-day setting. -
public static float3 GetCellCenter(int index)
Utility to get the world-space center for a given cell index. Delegates to CellMapSystem.GetCellCenter with kTextureSize. -
public static GroundPollution GetPollution(float3 position, NativeArray<GroundPollution> pollutionMap)
Samples pollution at an arbitrary world position. Uses: - CellMapSystem
.GetCell to locate the integer cell, - CellMapSystem
.GetCellCoords to compute fractional coordinates within the cell, -
Bilinear interpolation across the four surrounding cell values to return a sampled GroundPollution with interpolated m_Pollution (rounded to nearest int). Returns a default GroundPollution (all-zero) if position maps outside the texture bounds.
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[Preserve] protected override void OnCreate()
Initialization: - Calls base.OnCreate().
- Retrieves the SimulationSystem instance (m_SimulationSystem = base.World.GetOrCreateSystemManaged
()) for frame index access. - Calls CreateTextures(kTextureSize) (inherited from CellMapSystem) to create the underlying cell textures.
-
Sets up m_PollutionParameterGroup = GetEntityQuery(ComponentType.ReadOnly
()) and calls RequireForUpdate(m_PollutionParameterGroup) so the system runs only when the PollutionParameterData singleton is present. -
[Preserve] protected override void OnUpdate()
Schedules the PollutionFadeJob: - Constructs PollutionFadeJob with the map (m_Map from base), PollutionParameterData singleton, a RandomSeed.Next() instance, and the current simulation frame index.
- Schedules the job with JobHandle.CombineDependencies(m_WriteDependencies, m_ReadDependencies, base.Dependency) and adds the resulting dependency as a writer via AddWriter(base.Dependency).
-
Combines read/write dependencies into base.Dependency for proper synchronization with other systems.
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private struct PollutionFadeJob.Execute()
The job Execute method runs on worker threads (Burst): - Creates a Unity.Mathematics.Random from m_Random and m_Frame.
- Iterates all cells in m_PollutionMap and, for each cell with m_Pollution > 0, reduces pollution by a randomized rounded amount based on m_PollutionParameters.m_GroundFade / kUpdatesPerDay, clamped to zero, then writes the new value back into the array.
Usage Example
[Preserve]
protected override void OnCreate()
{
base.OnCreate();
m_SimulationSystem = base.World.GetOrCreateSystemManaged<SimulationSystem>();
CreateTextures(kTextureSize);
m_PollutionParameterGroup = GetEntityQuery(ComponentType.ReadOnly<PollutionParameterData>());
RequireForUpdate(m_PollutionParameterGroup);
}
Additional notes for modders:
- Use GetPollution(position, pollutionMap) to sample pollution at arbitrary positions; ensure you pass the correct NativeArray