Functional cell rootSource mechanics

src/main/kotlin/ru/dbotthepony/kstarbound/server/world/ServerWorld.kt

@@ -3,6 +3,7 @@ package ru.dbotthepony.kstarbound.server.world
 import com.google.gson.JsonElement
 import com.google.gson.JsonObject
 import it.unimi.dsi.fastutil.ints.IntArraySet
+import it.unimi.dsi.fastutil.objects.ObjectArrayList
 import it.unimi.dsi.fastutil.objects.ObjectArraySet
 import kotlinx.coroutines.async
 import kotlinx.coroutines.future.asCompletableFuture
@@ -51,6 +52,7 @@ import java.util.concurrent.CopyOnWriteArrayList
 import java.util.concurrent.RejectedExecutionException
 import java.util.concurrent.TimeUnit
 import java.util.function.Supplier
+import java.util.stream.Collectors
 
 class ServerWorld private constructor(
 	val server: StarboundServer,
@@ -167,22 +169,39 @@ class ServerWorld private constructor(
 		if (damage.amount <= 0.0)
 			return TileDamageResult.NONE
 
-		val actualPositions = positions.stream()
-			.map { geometry.wrap(it) }
-			.distinct()
-			.map { it to chunkMap[geometry.chunkFromCell(it)] }
-			.toList()
+		val actualPositions = ObjectArraySet<Pair<Vector2i, ServerChunk?>>()
+
+		for (pos in positions) {
+			val wrapped = geometry.wrap(pos)
+			val chunk = chunkMap[geometry.chunkFromCell(wrapped)]
+
+			if (chunk != null) {
+				val cell = chunk.getCell(wrapped - chunk.pos.tile)
+
+				if (cell.rootSource != null) {
+					actualPositions.add(geometry.wrap(cell.rootSource!!) to chunk)
+				} else {
+					actualPositions.add(wrapped to chunk)
+				}
+			} else {
+				actualPositions.add(wrapped to chunk)
+			}
+		}
 
 		var topMost = TileDamageResult.NONE
-
 		val damagedEntities = ObjectArraySet<TileEntity>()
 
 		for ((pos, chunk) in actualPositions) {
 			var damage = damage
 			var tileEntityResult = TileDamageResult.NONE
 
-			if (chunk?.getCell(pos - chunk.pos.tile)?.dungeonId in protectedDungeonIDs)
-				damage = damage.copy(type = TileDamageType.PROTECTED)
+			val getCell = chunk?.getCell(pos - chunk.pos.tile)
+
+			if (getCell != null) {
+				if (getCell.dungeonId in protectedDungeonIDs) {
+					damage = damage.copy(type = TileDamageType.PROTECTED)
+				}
+			}
 
 			if (!isBackground) {
 				for (entity in entitiesAtTile(pos)) {

src/main/kotlin/ru/dbotthepony/kstarbound/world/api/ImmutableCell.kt

@@ -33,6 +33,6 @@ data class ImmutableCell(
 	}
 
 	override fun mutable(): MutableCell {
-		return MutableCell(foreground.mutable(), background.mutable(), liquid.mutable(), dungeonId, blockBiome, envBiome, biomeTransition)
+		return MutableCell(foreground.mutable(), background.mutable(), liquid.mutable(), dungeonId, blockBiome, envBiome, biomeTransition, rootSource)
 	}
 }

src/main/kotlin/ru/dbotthepony/kstarbound/world/api/MutableCell.kt

@@ -55,7 +55,7 @@ data class MutableCell(
 	}
 
 	override fun immutable(): ImmutableCell {
-		return POOL.intern(ImmutableCell(foreground.immutable(), background.immutable(), liquid.immutable(), dungeonId, blockBiome, envBiome, biomeTransition))
+		return POOL.intern(ImmutableCell(foreground.immutable(), background.immutable(), liquid.immutable(), dungeonId, blockBiome, envBiome, biomeTransition, rootSource))
 	}
 
 	override fun mutable(): MutableCell {

src/main/kotlin/ru/dbotthepony/kstarbound/world/entities/tile/PlantEntity.kt

@@ -654,9 +654,10 @@ class PlantEntity() : TileEntity() {
 					if (world.getCell(root).foreground.material.isEmptyTile) {
 						if (fallsWhenDead) {
 							breakAtPosition(tilePosition, position)
-						} else {
-							remove(RemovalReason.DYING)
 						}
+
+						remove(RemovalReason.DYING)
+						return
 					}
 				}
 			}
@@ -672,7 +673,7 @@ class PlantEntity() : TileEntity() {
 		this.metaBoundingBox = this.calculatedBoundingBox + this.position
 		this.occupySpaces = this.calculatedOccupySpaces.stream().map { it + tilePosition }.collect(ImmutableSet.toImmutableSet())
 		this.roots = this.calculatedRoots.stream().map { it + tilePosition }.collect(ImmutableSet.toImmutableSet())
-		markSpacesDirty()
+		markRootsDirty()
 		updateSpatialPosition()
 	}
 

src/main/kotlin/ru/dbotthepony/kstarbound/world/entities/tile/TileEntity.kt

@@ -113,12 +113,14 @@ abstract class TileEntity : AbstractEntity() {
 	protected open fun onPositionUpdated() {
 		updateSpatialPosition()
 		markSpacesDirty()
+		markRootsDirty()
 	}
 
 	override fun onJoinWorld(world: World<*, *>) {
 		super.onJoinWorld(world)
 		updateSpatialPosition()
 		markSpacesDirty()
+		markRootsDirty()
 	}
 
 	override fun onRemove(world: World<*, *>, reason: RemovalReason) {
@@ -157,6 +159,41 @@ abstract class TileEntity : AbstractEntity() {
 					}
 				}
 			}
+
+			// remove roots
+			if (!updateRoots(listOf())) {
+				// we were unable to remove all roots...
+				// create a task to try not to leave world in inconsistent state!
+				val currentRoots = currentRoots
+				val tilePosition = tilePosition
+
+				world.eventLoop.scope.launch {
+					world as ServerWorld
+					val tickets = ArrayList<ServerChunk.ITicket>()
+
+					try {
+						currentRoots.forEach { p ->
+							tickets.add(world.permanentChunkTicket(world.geometry.chunkFromCell(p.x, p.y), ChunkState.EMPTY).await() ?: return@forEach)
+						}
+
+						tickets.forEach { it.chunk.await() }
+
+						for (space in currentRoots) {
+							val cell = world.getCell(space).mutable()
+
+							if (cell.rootSource == tilePosition) {
+								cell.rootSource = null
+							}
+
+							if (!world.setCell(space, cell)) {
+								LOGGER.warn("Unable to clear root source at ${space}, world left in inconsistent state.")
+							}
+						}
+					} finally {
+						tickets.forEach { it.cancel() }
+					}
+				}
+			}
 		}
 	}
 
@@ -222,6 +259,62 @@ abstract class TileEntity : AbstractEntity() {
 		return clear
 	}
 
+	protected fun updateRoots(desired: Collection<Vector2i>): Boolean {
+		val toRemove = ArrayList<Vector2i>()
+		val toPlace = ArrayList<Vector2i>()
+
+		for (current in currentRoots) {
+			if (current !in desired) {
+				toRemove.add(current)
+			}
+		}
+
+		for (pos in desired) {
+			if (pos !in currentRoots) {
+				toPlace.add(pos)
+			}
+		}
+
+		var clear = true
+
+		for (pos in toRemove) {
+			val cell = world.getCell(pos).mutable()
+
+			if (cell.rootSource == tilePosition) {
+				cell.rootSource = null
+
+				if (world.setCell(pos, cell)) {
+					currentRoots.remove(pos)
+				} else {
+					clear = false
+				}
+			} else {
+				currentRoots.remove(pos)
+			}
+		}
+
+		for (pos in toPlace) {
+			val cell = world.getCell(pos).mutable()
+
+			if (cell.rootSource == null) {
+				cell.rootSource = tilePosition
+
+				if (world.setCell(pos, cell)) {
+					currentRoots.add(pos)
+				} else {
+					clear = false
+				}
+			} else {
+				// bugger, someone rooted onto our tile!
+				// will try again...
+				// TODO: however, shouldn't we just ignore this and move on?
+				clear = false
+			}
+		}
+
+		return clear
+	}
+
 	fun updateMaterialSpacesNow() {
 		needToUpdateSpaces = false
 
@@ -232,12 +325,26 @@ abstract class TileEntity : AbstractEntity() {
 		}
 	}
 
+	fun updateRootsNow() {
+		needToUpdateRoots = false
+
+		// only server can update entity tiles
+		// even if this tile entity is owned by client
+		if (world.isServer) {
+			needToUpdateRoots = !updateRoots(roots)
+		}
+	}
+
 	override fun tick(delta: Double) {
 		super.tick(delta)
 
 		if (world.isServer && needToUpdateSpaces) {
 			updateMaterialSpacesNow()
 		}
+
+		if (world.isServer && needToUpdateRoots) {
+			updateRootsNow()
+		}
 	}
 
 	companion object {