Give each entity an UID and make entity classes open

buildSrc/src/main/kotlin/space/uranos/mdsp/generator/EntitiesGenerator.kt

@@ -78,6 +78,7 @@ class EntitiesGenerator(
 
             val type = TypeSpec.classBuilder(name)
                 .superclass(ENTITY_TYPE)
+                .addModifiers(KModifier.OPEN)
                 .addProperty(
                     PropertySpec.builder("type", ENTITY_TYPE_TYPE, KModifier.OVERRIDE, KModifier.FINAL)
                         .initializer("Type")

gradle.properties

@@ -1,10 +1,2 @@
 # suppress inspection "UnusedProperty" for whole file
 kotlin.code.style=official
-version.kotlin=1.4.20
-version.netty=4.1.54.Final
-version.moshi=1.11.0
-version.kotlinx-coroutines=1.4.2
-version.slf4j=1.7.30
-version.junit=5.7.0
-version.strikt=0.28.0
-version.guava=30.0-jre

uranos-api/src/main/kotlin/space/uranos/entity/Entity.kt

@@ -5,13 +5,24 @@
 
 package space.uranos.entity
 
-import space.uranos.Location
+import space.uranos.Uranos
 import java.util.*
-import kotlin.reflect.KClass
 
 abstract class Entity internal constructor() {
-    val uuid: UUID = UUID.randomUUID()
+    /**
+     * An integer unique to this entity which will not be persisted, for example when the entity is serialized.
+     */
+    val uid: Int = Uranos.claimEntityID()
+
+    /**
+     * The UUID of this entity.
+     *
+     * If the entity is a player and the server uses authentication, it is the player's UUID, if it is not,
+     * it is a UUIDv3 generated from a string consisting of "OfflinePlayer:" and the player's username.
+     *
+     * Otherwise, it is usually randomly generated.
+     */
+    open val uuid: UUID = UUID.randomUUID()
 
     abstract val type: EntityType
-    val globallyUniqueNumericID: Int = 0 // TODO: Get a real value
 }

uranos-api/src/main/kotlin/space/uranos/entity/ItemEntity.kt

@@ -7,8 +7,8 @@ package space.uranos.entity
 
 import space.uranos.Position
 
-class ItemEntity(override var position: Position) : ObjectEntity() {
+open class ItemEntity(override var position: Position) : ObjectEntity() {
-  override val type: EntityType = Type
+  final override val type: EntityType = Type
 
   companion object Type : ItemEntityType()
 }

uranos-api/src/main/kotlin/space/uranos/server/Server.kt

@@ -57,6 +57,13 @@ interface Server {
     val developmentMode: Boolean
     val minimumLogLevel: Logger.Level
 
+    /**
+     * Returns an unused entity ID.
+     *
+     * **Should not be used by plugins.**
+     */
+    fun claimEntityID(): Int
+
     /**
      * Initiates shutting down the server.
      */

uranos-packet-codecs/src/main/kotlin/space/uranos/net/packet/play/ChunkDataPacketCodec.kt

@@ -67,10 +67,7 @@ object ChunkDataPacketCodec : OutgoingPacketCodec<ChunkDataPacket>(0x20, ChunkDa
         // Blocks
         val dataBuf = Unpooled.buffer() // TODO: Set an initial capacity
         for (section in data.sections.filterNotNull()) {
-            val ids = section.map {
+            val ids = section.map { it.material().codec.getStateID(it) }.toIntArray()
-                println(it)
-                it.material().codec.getStateID(it)
-            }.toIntArray()
             dataBuf.writeShort(ids.count { !(it == AirBlock.codec.id || it == CaveAirBlock.codec.id) })
             dataBuf.writeByte(numberOfBitsPerBlock)
 

uranos-packet-codecs/src/main/kotlin/space/uranos/net/packet/play/SpawnLivingEntityPacketCodec.kt

@@ -6,7 +6,6 @@
 package space.uranos.net.packet.play
 
 import io.netty.buffer.ByteBuf
-import space.uranos.Difficulty
 import space.uranos.entity.LivingEntity
 import space.uranos.net.MinecraftProtocolDataTypes.writeUUID
 import space.uranos.net.MinecraftProtocolDataTypes.writeVarInt
@@ -30,7 +29,7 @@ object SpawnLivingEntityPacketCodec : OutgoingPacketCodec<SpawnLivingEntityPacke
     }
 
     fun getPacketFromEntity(entity: LivingEntity) = SpawnLivingEntityPacket(
-        entity.globallyUniqueNumericID,
+        entity.uid,
         entity.uuid,
         entity.type,
         entity.position,

uranos-packet-codecs/src/main/kotlin/space/uranos/net/packet/play/SpawnObjectEntityPacketCodec.kt

@@ -6,13 +6,11 @@
 package space.uranos.net.packet.play
 
 import io.netty.buffer.ByteBuf
-import space.uranos.entity.Entity
 import space.uranos.entity.ItemEntity
 import space.uranos.entity.ObjectEntity
 import space.uranos.net.MinecraftProtocolDataTypes.writeUUID
 import space.uranos.net.MinecraftProtocolDataTypes.writeVarInt
 import space.uranos.net.packet.OutgoingPacketCodec
-import java.lang.IllegalArgumentException
 
 object SpawnObjectEntityPacketCodec : OutgoingPacketCodec<SpawnObjectEntityPacket>(0x00, SpawnObjectEntityPacket::class) {
     @Suppress("DuplicatedCode")
@@ -32,7 +30,7 @@ object SpawnObjectEntityPacketCodec : OutgoingPacketCodec<SpawnObjectEntityPacke
     }
 
     fun getPacketFromEntity(entity: ObjectEntity) = SpawnObjectEntityPacket(
-        entity.globallyUniqueNumericID,
+        entity.uid,
         entity.uuid,
         entity.type,
         entity.position,

uranos-packet-codecs/src/main/kotlin/space/uranos/net/packet/play/SpawnPaintingPacketCodec.kt

@@ -7,14 +7,12 @@ package space.uranos.net.packet.play
 
 import io.netty.buffer.ByteBuf
 import space.uranos.CardinalDirection
-import space.uranos.Difficulty
 import space.uranos.entity.PaintingEntity
 import space.uranos.entity.PaintingMotive
 import space.uranos.net.MinecraftProtocolDataTypes.writeUUID
 import space.uranos.net.MinecraftProtocolDataTypes.writeVarInt
 import space.uranos.net.MinecraftProtocolDataTypes.writeVoxelLocation
 import space.uranos.net.packet.OutgoingPacketCodec
-import space.uranos.world.Voxel
 import space.uranos.world.VoxelLocation
 import kotlin.math.max
 
@@ -33,7 +31,7 @@ object SpawnPaintingPacketCodec : OutgoingPacketCodec<SpawnPaintingPacket>(0x03,
     }
 
     fun getPacketFromEntity(entity: PaintingEntity) = SpawnPaintingPacket(
-        entity.globallyUniqueNumericID,
+        entity.uid,
         entity.uuid,
         entity.motive,
         getCenterLocation(entity.topLeftLocation, entity.motive),

uranos-server/src/main/kotlin/space/uranos/UranosServer.kt

@@ -28,6 +28,7 @@ import space.uranos.world.Dimension
 import java.io.File
 import java.security.KeyPair
 import java.util.concurrent.Executors
+import java.util.concurrent.atomic.AtomicInteger
 import kotlin.coroutines.CoroutineContext
 import kotlin.system.exitProcess
 
@@ -89,6 +90,15 @@ class UranosServer internal constructor() : Server {
     override val eventBus = UranosEventBus(developmentMode)
     override val eventHandlerPositions = UranosEventHandlerPositionManager()
 
+    private val nextEntityID = AtomicInteger()
+    override fun claimEntityID() = nextEntityID.incrementAndGet()
+
+    override fun shutdown() {
+        runBlocking {
+            scheduler.shutdown()
+        }
+    }
+
     private fun failInitialization(t: Throwable): Nothing {
         logger.error("Server initialization failed:", t)
         exitProcess(1)
@@ -107,12 +117,6 @@ class UranosServer internal constructor() : Server {
         scheduler.startTicking()
     }
 
-    override fun shutdown() {
-        runBlocking {
-            scheduler.shutdown()
-        }
-    }
-
     companion object {
         val VERSION = UranosServer::class.java.`package`.implementationVersion ?: "development"
         val VERSION_WITH_V = if (VERSION == "development") VERSION else "v$VERSION"

uranos-server/src/test/kotlin/space/uranos/event/EventBusTest.kt

@@ -60,14 +60,9 @@ class EventBusTest {
         )
 
         val actualOrder = (Uranos.eventHandlerPositions as UranosEventHandlerPositionManager).positions
-        println(actualOrder)
-
         Uranos.eventHandlerPositions.insertAfter(EventHandlerPosition.FIRST, Position1, Position5)
-        println(actualOrder)
         Uranos.eventHandlerPositions.insertBefore(Position1, Position2, Position4)
-        println(actualOrder)
         Uranos.eventHandlerPositions.insert(Position3, Position6)
-        println(actualOrder)
 
         actualOrder.forEachIndexed { index, position ->
             expectThat(index).isEqualTo(expectedOrder.indexOf(position))