[Fix] Flatten Terrain

Assets/Features/VoxelWorld/Runtime/VoxelWorldGenerator.Spawns.cs

@@ -0,0 +1,232 @@
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace InfiniteWorld.VoxelWorld
+{
+    public sealed partial class VoxelWorldGenerator
+    {
+        private readonly Dictionary<Vector2Int, List<SpawnedPlacementRuntime>> spawnedPlacementsByChunk = new Dictionary<Vector2Int, List<SpawnedPlacementRuntime>>();
+        private readonly Dictionary<long, SpawnedPlacementRuntime> spawnedPlacementsById = new Dictionary<long, SpawnedPlacementRuntime>();
+        private readonly HashSet<long> disabledSpawnIds = new HashSet<long>();
+
+        private Transform placementRoot;
+
+        public IReadOnlyCollection<long> DisabledSpawnIds => disabledSpawnIds;
+
+        public bool IsSpawnDisabled(long spawnId)
+        {
+            return disabledSpawnIds.Contains(spawnId);
+        }
+
+        public bool DisableSpawn(long spawnId)
+        {
+            if (!disabledSpawnIds.Add(spawnId))
+            {
+                return false;
+            }
+
+            if (spawnedPlacementsById.TryGetValue(spawnId, out SpawnedPlacementRuntime runtime))
+            {
+                RemoveSpawnedPlacement(runtime);
+            }
+
+            return true;
+        }
+
+        public bool EnableSpawn(long spawnId)
+        {
+            return disabledSpawnIds.Remove(spawnId);
+        }
+
+        public void ClearDisabledSpawns()
+        {
+            disabledSpawnIds.Clear();
+        }
+
+        private void EnsurePlacementRoot()
+        {
+            if (placementRoot != null)
+            {
+                return;
+            }
+
+            Transform existing = transform.Find("WorldPlacements");
+            if (existing != null)
+            {
+                placementRoot = existing;
+                return;
+            }
+
+            GameObject root = new GameObject("WorldPlacements");
+            root.transform.SetParent(transform, false);
+            placementRoot = root.transform;
+        }
+
+        private void TrySpawnChunkPlacements(Vector2Int chunkCoord)
+        {
+            EnsurePlacementRoot();
+            if (placementRoot == null || spawnedPlacementsByChunk.ContainsKey(chunkCoord))
+            {
+                return;
+            }
+
+            WorldChunkPlacementPlan plan = GetChunkPlacementPlan(chunkCoord);
+            IReadOnlyList<WorldSpawnPoint> spawnPoints = plan.SpawnPoints;
+            if (spawnPoints == null || spawnPoints.Count == 0)
+            {
+                return;
+            }
+
+            List<SpawnedPlacementRuntime> chunkPlacements = new List<SpawnedPlacementRuntime>(spawnPoints.Count);
+            for (int i = 0; i < spawnPoints.Count; i++)
+            {
+                WorldSpawnPoint spawnPoint = spawnPoints[i];
+                if (disabledSpawnIds.Contains(spawnPoint.SpawnId) || spawnedPlacementsById.ContainsKey(spawnPoint.SpawnId))
+                {
+                    continue;
+                }
+
+                if (!TryResolveSpawnPrefab(spawnPoint, out GameObject prefab) || prefab == null)
+                {
+                    continue;
+                }
+
+                GameObject instance = Object.Instantiate(prefab, spawnPoint.Position, spawnPoint.Rotation, placementRoot);
+                instance.name = $"{prefab.name}_{spawnPoint.ChunkCoord.x}_{spawnPoint.ChunkCoord.y}_{spawnPoint.SpawnOrdinalInChunk}";
+                SpawnedPlacementRuntime runtime = new SpawnedPlacementRuntime(spawnPoint.SpawnId, chunkCoord, spawnPoint.CollectionIndex, spawnPoint.EntryIndex, instance);
+                chunkPlacements.Add(runtime);
+                spawnedPlacementsById.Add(runtime.SpawnId, runtime);
+            }
+
+            if (chunkPlacements.Count > 0)
+            {
+                spawnedPlacementsByChunk[chunkCoord] = chunkPlacements;
+            }
+        }
+
+        private bool TryResolveSpawnPrefab(WorldSpawnPoint spawnPoint, out GameObject prefab)
+        {
+            prefab = null;
+            if (config == null || config.placementCollections == null)
+            {
+                return false;
+            }
+
+            if (spawnPoint.CollectionIndex < 0 || spawnPoint.CollectionIndex >= config.placementCollections.Count)
+            {
+                return false;
+            }
+
+            WorldPrefabCollection collection = config.placementCollections[spawnPoint.CollectionIndex];
+            if (collection == null || collection.entries == null || spawnPoint.EntryIndex < 0 || spawnPoint.EntryIndex >= collection.entries.Count)
+            {
+                return false;
+            }
+
+            WorldPrefabEntry entry = collection.entries[spawnPoint.EntryIndex];
+            if (entry == null)
+            {
+                return false;
+            }
+
+            prefab = entry.prefab;
+            return prefab != null;
+        }
+
+        private void DespawnChunkPlacements(Vector2Int chunkCoord)
+        {
+            if (!spawnedPlacementsByChunk.TryGetValue(chunkCoord, out List<SpawnedPlacementRuntime> chunkPlacements))
+            {
+                return;
+            }
+
+            for (int i = 0; i < chunkPlacements.Count; i++)
+            {
+                SpawnedPlacementRuntime runtime = chunkPlacements[i];
+                spawnedPlacementsById.Remove(runtime.SpawnId);
+                DestroyPlacementInstance(runtime.Instance);
+            }
+
+            spawnedPlacementsByChunk.Remove(chunkCoord);
+        }
+
+        private void RemoveSpawnedPlacement(SpawnedPlacementRuntime runtime)
+        {
+            spawnedPlacementsById.Remove(runtime.SpawnId);
+            if (spawnedPlacementsByChunk.TryGetValue(runtime.ChunkCoord, out List<SpawnedPlacementRuntime> chunkPlacements))
+            {
+                chunkPlacements.RemoveAll(item => item.SpawnId == runtime.SpawnId);
+                if (chunkPlacements.Count == 0)
+                {
+                    spawnedPlacementsByChunk.Remove(runtime.ChunkCoord);
+                }
+            }
+
+            DestroyPlacementInstance(runtime.Instance);
+        }
+
+        private void CleanupSpawnedPlacements()
+        {
+            foreach (KeyValuePair<Vector2Int, List<SpawnedPlacementRuntime>> pair in spawnedPlacementsByChunk)
+            {
+                List<SpawnedPlacementRuntime> chunkPlacements = pair.Value;
+                for (int i = 0; i < chunkPlacements.Count; i++)
+                {
+                    DestroyPlacementInstance(chunkPlacements[i].Instance);
+                }
+            }
+
+            spawnedPlacementsByChunk.Clear();
+            spawnedPlacementsById.Clear();
+
+            if (placementRoot != null)
+            {
+                if (Application.isPlaying)
+                {
+                    Object.Destroy(placementRoot.gameObject);
+                }
+                else
+                {
+                    Object.DestroyImmediate(placementRoot.gameObject);
+                }
+
+                placementRoot = null;
+            }
+        }
+
+        private static void DestroyPlacementInstance(GameObject instance)
+        {
+            if (instance == null)
+            {
+                return;
+            }
+
+            if (Application.isPlaying)
+            {
+                Object.Destroy(instance);
+            }
+            else
+            {
+                Object.DestroyImmediate(instance);
+            }
+        }
+
+        private sealed class SpawnedPlacementRuntime
+        {
+            public SpawnedPlacementRuntime(long spawnId, Vector2Int chunkCoord, int collectionIndex, int entryIndex, GameObject instance)
+            {
+                SpawnId = spawnId;
+                ChunkCoord = chunkCoord;
+                CollectionIndex = collectionIndex;
+                EntryIndex = entryIndex;
+                Instance = instance;
+            }
+
+            public long SpawnId { get; }
+            public Vector2Int ChunkCoord { get; }
+            public int CollectionIndex { get; }
+            public int EntryIndex { get; }
+            public GameObject Instance { get; }
+        }
+    }
+}

Assets/Features/VoxelWorld/Runtime/VoxelWorldGenerator.Spawns.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: f7d0d16ba43223c41bd21fbe9333d819

Assets/Features/VoxelWorld/Runtime/VoxelWorldGenerator.cs

@@ -75,6 +75,7 @@ namespace InfiniteWorld.VoxelWorld
             EnsureRuntimeData();
             EnsureChunkRoot();
             EnsureRegionRoot();
+            EnsurePlacementRoot();
             TryResolveStreamTarget();
         }
 
@@ -83,6 +84,7 @@ namespace InfiniteWorld.VoxelWorld
             EnsureRuntimeData();
             EnsureChunkRoot();
             EnsureRegionRoot();
+            EnsurePlacementRoot();
             if (!TryResolveStreamTarget())
             {
                 return;
@@ -121,6 +123,7 @@ namespace InfiniteWorld.VoxelWorld
             CleanupChunks();
             CleanupRegions();
             CleanupPlacementPlans();
+            CleanupSpawnedPlacements();
             atlas?.Dispose();
             atlas = null;
         }
@@ -290,6 +293,7 @@ namespace InfiniteWorld.VoxelWorld
                 {
                     chunkPlacementPlans.Remove(coord);
                 }
+                DespawnChunkPlacements(coord);
                 runtime.Dispose();
                 TryDisposeRegionIfEmpty(regionCoord);
                 QueueNeighborRefresh(coord);
@@ -804,6 +808,8 @@ namespace InfiniteWorld.VoxelWorld
                 runtime.State = ChunkState.ReadyToRender;
             }
 
+            TrySpawnChunkPlacements(result.Coord);
+
             return true;
         }
 
@@ -890,6 +896,7 @@ namespace InfiniteWorld.VoxelWorld
             }
 
             chunks.Clear();
+            CleanupSpawnedPlacements();
             dirtyChunkMeshes.Clear();
             queuedChunkMeshes.Clear();
             pendingNeighborRefreshes.Clear();