Table of Contents

Class AdjacencySystem

Namespace
Core.Systems
Assembly
Core.dll

ENGINE LAYER: Province adjacency system

Stores which provinces are adjacent (share a border) for movement validation. Populated from FastAdjacencyScanner during map initialization.

Architecture:

  • Dictionary{ushort, HashSet{ushort}}: provinceID → set of neighbor IDs
  • Bidirectional: if A is adjacent to B, then B is adjacent to A
  • Read-only after initialization

Usage:

  • Initialize with SetAdjacencies(adjacencyData)
  • Query with IsAdjacent(province1, province2)
  • Get all neighbors with GetNeighbors(provinceID)

Performance:

  • IsAdjacent: O(1) HashSet lookup
  • GetNeighbors: O(1) dictionary lookup
  • Memory: ~6 neighbors × 13,350 provinces × 2 bytes = ~160 KB
public class AdjacencySystem
Inheritance
object
AdjacencySystem

Constructors

AdjacencySystem() 

public AdjacencySystem()

Properties

IsInitialized

Check if system is initialized

public bool IsInitialized { get; }

Property Value

bool

ProvinceCount

Get total province count

public int ProvinceCount { get; }

Property Value

int

TotalAdjacencyPairs

Get total adjacency pair count

public int TotalAdjacencyPairs { get; }

Property Value

int

Methods

Dispose()

Dispose native allocations

public void Dispose()

FindBridgeProvinces(IEnumerable<ushort>, Func<ushort, bool>, List<ushort>)

Find all bridge provinces within a region. These are strategic choke points where losing control would split territory.

public void FindBridgeProvinces(IEnumerable<ushort> regionProvinces, Func<ushort, bool> regionPredicate, List<ushort> resultBuffer)

Parameters

regionProvinces IEnumerable<ushort>

Set of provinces to check

regionPredicate Func<ushort, bool>

Predicate defining what's in the region

resultBuffer List<ushort>

Pre-allocated list to fill with bridge provinces

GetConnectedRegion(ushort, Func<ushort, bool>)

Get all provinces connected to a starting province (allocating version).

public HashSet<ushort> GetConnectedRegion(ushort startProvince, Func<ushort, bool> predicate)

Parameters

startProvince ushort
predicate Func<ushort, bool>

Returns

HashSet<ushort>

GetConnectedRegion(ushort, Func<ushort, bool>, HashSet<ushort>)

Get all provinces connected to a starting province that match a predicate. Uses BFS flood fill. Returns the connected region including the start province.

Example: Get all provinces owned by a country connected to capitalProvince GetConnectedRegion(capital, id => provinceSystem.GetOwner(id) == countryId)

public void GetConnectedRegion(ushort startProvince, Func<ushort, bool> predicate, HashSet<ushort> resultBuffer)

Parameters

startProvince ushort

Starting province for flood fill

predicate Func<ushort, bool>

Filter - only provinces passing this are included and traversed

resultBuffer HashSet<ushort>

Pre-allocated set to fill (cleared before use)

GetNativeData()

Get read-only native adjacency data for Burst jobs.

public NativeAdjacencyData GetNativeData()

Returns

NativeAdjacencyData

GetNeighborCount(ushort)

Get neighbor count for a province

public int GetNeighborCount(ushort provinceId)

Parameters

provinceId ushort

Returns

int

GetNeighbors(ushort, Allocator)

Get all neighbors for a province Returns empty array if province has no neighbors or doesn't exist Caller must dispose the returned NativeArray

public NativeArray<ushort> GetNeighbors(ushort provinceId, Allocator allocator = Allocator.TempJob)

Parameters

provinceId ushort
allocator Allocator

Returns

NativeArray<ushort>

GetNeighbors(ushort, NativeList<ushort>)

Get all neighbors for a province, filling an existing NativeList (zero allocations) Clears the list before filling it with neighbors Used by PathfindingSystem for allocation-free pathfinding

public void GetNeighbors(ushort provinceId, NativeList<ushort> resultBuffer)

Parameters

provinceId ushort
resultBuffer NativeList<ushort>

GetNeighborsWhere(ushort, Func<ushort, bool>)

Get neighbors that match a predicate (allocating version). Prefer the buffer version for hot paths.

public List<ushort> GetNeighborsWhere(ushort provinceId, Func<ushort, bool> predicate)

Parameters

provinceId ushort
predicate Func<ushort, bool>

Returns

List<ushort>

GetNeighborsWhere(ushort, Func<ushort, bool>, List<ushort>)

Get neighbors that match a predicate. Example: GetNeighborsWhere(provinceId, id => provinceSystem.GetOwner(id) == enemyCountry)

public void GetNeighborsWhere(ushort provinceId, Func<ushort, bool> predicate, List<ushort> resultBuffer)

Parameters

provinceId ushort

Province to get neighbors for

predicate Func<ushort, bool>

Filter function - returns true for neighbors to include

resultBuffer List<ushort>

Pre-allocated list to fill (cleared before use)

GetSharedBorderProvinces(IEnumerable<ushort>, HashSet<ushort>)

Get provinces where two countries share a border (allocating version).

public List<ushort> GetSharedBorderProvinces(IEnumerable<ushort> ownedProvinces, HashSet<ushort> foreignProvinces)

Parameters

ownedProvinces IEnumerable<ushort>
foreignProvinces HashSet<ushort>

Returns

List<ushort>

GetSharedBorderProvinces(IEnumerable<ushort>, HashSet<ushort>, List<ushort>)

Get provinces where two countries share a border. Returns provinces from country1 that are adjacent to any province in country2.

Example: Find where France borders Germany GetSharedBorderProvinces(frenchProvinces, germanProvinces, borderBuffer)

public void GetSharedBorderProvinces(IEnumerable<ushort> ownedProvinces, HashSet<ushort> foreignProvinces, List<ushort> resultBuffer)

Parameters

ownedProvinces IEnumerable<ushort>

Provinces belonging to first country

foreignProvinces HashSet<ushort>

Provinces belonging to second country

resultBuffer List<ushort>

Pre-allocated list to fill with border provinces from ownedProvinces

GetStatistics()

Get adjacency statistics for debugging (string format). Prefer GetStats() for programmatic access.

public string GetStatistics()

Returns

string

GetStats()

Get queryable adjacency statistics.

public AdjacencyStats GetStats()

Returns

AdjacencyStats

IsAdjacent(ushort, ushort)

Check if two provinces are adjacent (share a border)

public bool IsAdjacent(ushort province1, ushort province2)

Parameters

province1 ushort
province2 ushort

Returns

bool

IsBridgeProvince(ushort, Func<ushort, bool>)

Check if a province is a "bridge" - removing it would disconnect the region.

A bridge province has the property that the region becomes disconnected if it's removed. Useful for strategic AI (critical choke points).

Algorithm: Check if any two neighbors of the province can still reach each other without going through this province.

public bool IsBridgeProvince(ushort province, Func<ushort, bool> regionPredicate)

Parameters

province ushort

Province to check

regionPredicate Func<ushort, bool>

Predicate defining the region (e.g., same owner)

Returns

bool

True if removing this province would disconnect the region

SetAdjacencies(Dictionary<int, HashSet<int>>)

Initialize adjacency data from FastAdjacencyScanner results Converts from Dictionary{int, HashSet{int}} to Dictionary{ushort, HashSet{ushort}} Also builds native MultiHashMap for Burst job compatibility

public void SetAdjacencies(Dictionary<int, HashSet<int>> scanResults)

Parameters

scanResults Dictionary<int, HashSet<int>>
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