Add basic support for persistent game worlds

src/main/java/xyz/nucleoid/plasmid/api/game/world/GameSpaceWorlds.java

@@ -1,6 +1,8 @@
 package xyz.nucleoid.plasmid.api.game.world;
 
 import net.minecraft.server.world.ServerWorld;
+import net.minecraft.util.Identifier;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import xyz.nucleoid.fantasy.RuntimeWorldConfig;
 import xyz.nucleoid.plasmid.api.game.GameSpace;
@@ -21,6 +23,20 @@ public interface GameSpaceWorlds extends Iterable<ServerWorld> {
      */
     ServerWorld add(RuntimeWorldConfig worldConfig);
 
+
+    /**
+     * Creates (or loads) and adds a persistent world to be associated with this {@link GameSpace}.
+     * When the game is closed, the world will be unloaded, with all chunks saved.
+     * If world using this id is already loaded, this method will throw an exception.
+     *
+     * @param worldConfig a config describing how the new world should be created and how it should behave
+     * @return the created world instance
+     * @see RuntimeWorldConfig
+     */
+    @ApiStatus.Experimental
+    ServerWorld addPersistent(Identifier identifier, RuntimeWorldConfig worldConfig);
+
+
     /**
      * Removes and deletes a temporary world that is associated with this {@link GameSpace}.
      * The passed world must have been created through {@link GameSpaceWorlds#add(RuntimeWorldConfig)}.

src/main/java/xyz/nucleoid/plasmid/impl/game/manager/ManagedGameSpaceWorlds.java

@@ -3,7 +3,9 @@
 import com.google.common.collect.Iterators;
 import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
 import net.minecraft.registry.RegistryKey;
+import net.minecraft.registry.RegistryKeys;
 import net.minecraft.server.world.ServerWorld;
+import net.minecraft.util.Identifier;
 import net.minecraft.world.GameRules;
 import net.minecraft.world.World;
 import org.jetbrains.annotations.NotNull;
@@ -37,13 +39,29 @@ public ServerWorld add(RuntimeWorldConfig worldConfig) {
         return worldHandle.asWorld();
     }
 
+    @Override
+    public ServerWorld addPersistent(Identifier identifier, RuntimeWorldConfig worldConfig) {
+        var world = this.space.getServer().getWorld(RegistryKey.of(RegistryKeys.WORLD, identifier));
+        if (world != null) {
+            throw new RuntimeException("World '" + identifier + "' is already loaded!");
+        }
+
+        applyDefaultsTo(worldConfig);
+
+        var worldHandle = Fantasy.get(this.space.getServer()).getOrOpenPersistentWorld(identifier, worldConfig);
+        this.worlds.put(worldHandle.asWorld().getRegistryKey(), worldHandle);
+        this.space.onAddWorld(worldHandle);
+
+        return worldHandle.asWorld();
+    }
+
     @Override
     public boolean remove(ServerWorld world) {
         var dimension = world.getRegistryKey();
         var worldHandle = this.worlds.remove(dimension);
         if (worldHandle != null) {
             this.space.onRemoveWorld(dimension);
-            worldHandle.delete();
+            worldHandle.unload();
             return true;
         } else {
             return false;
@@ -52,7 +70,7 @@ public boolean remove(ServerWorld world) {
 
     void clear() {
         for (var worldHandler : this.worlds.values()) {
-            worldHandler.delete();
+            worldHandler.unload();
         }
         this.worlds.clear();
     }

src/testmod/java/xyz/nucleoid/plasmid/test/PersistentGame.java

@@ -0,0 +1,55 @@
+package xyz.nucleoid.plasmid.test;
+
+import net.minecraft.registry.RegistryKeys;
+import net.minecraft.util.*;
+import net.minecraft.util.math.Vec3d;
+import net.minecraft.world.GameMode;
+import net.minecraft.world.GameRules;
+import net.minecraft.world.biome.BiomeKeys;
+import net.minecraft.world.gen.chunk.FlatChunkGenerator;
+import net.minecraft.world.gen.chunk.FlatChunkGeneratorConfig;
+import xyz.nucleoid.fantasy.RuntimeWorldConfig;
+import xyz.nucleoid.plasmid.api.game.*;
+import xyz.nucleoid.plasmid.api.game.event.GamePlayerEvents;
+import xyz.nucleoid.plasmid.api.game.player.JoinOffer;
+import xyz.nucleoid.plasmid.api.game.rule.GameRuleType;
+import xyz.nucleoid.stimuli.event.EventResult;
+import xyz.nucleoid.stimuli.event.player.PlayerDeathEvent;
+
+import java.util.List;
+import java.util.Optional;
+
+public final class PersistentGame {
+    public static GameOpenProcedure open(GameOpenContext<Unit> context) {
+        var biome =  context.server().getRegistryManager().getOrThrow(RegistryKeys.BIOME).getOrThrow(BiomeKeys.CHERRY_GROVE);
+
+        var worldConfig = new RuntimeWorldConfig()
+                .setGenerator(new FlatChunkGenerator(new FlatChunkGeneratorConfig(Optional.empty(), biome, List.of())))
+                .setTimeOfDay(6000)
+                .setGameRule(GameRules.KEEP_INVENTORY, true);
+
+        return context.open((activity) -> {
+            var gameSpace = activity.getGameSpace();
+            var world = gameSpace.getWorlds().addPersistent(Identifier.of("testmod", "persistent_world"), worldConfig);
+
+
+            activity.listen(GamePlayerEvents.OFFER, JoinOffer::accept);
+            activity.listen(GamePlayerEvents.ACCEPT, acceptor ->
+                    acceptor.teleport(world, new Vec3d(0.0, 65.0, 0.0))
+                            .thenRunForEach(joiningPlayer -> {
+                                joiningPlayer.changeGameMode(GameMode.CREATIVE);
+                            })
+            );
+
+
+            activity.allow(GameRuleType.PVP).allow(GameRuleType.MODIFY_ARMOR);
+            activity.deny(GameRuleType.FALL_DAMAGE).deny(GameRuleType.HUNGER);
+            activity.deny(GameRuleType.THROW_ITEMS);
+
+            activity.listen(PlayerDeathEvent.EVENT, (player, source) -> {
+                player.setPos(0.0, 65.0, 0.0);
+                return EventResult.DENY;
+            });
+        });
+    }
+}

src/testmod/java/xyz/nucleoid/plasmid/test/TestInitializer.java

@@ -1,5 +1,6 @@
 package xyz.nucleoid.plasmid.test;
 
+import com.mojang.serialization.MapCodec;
 import eu.pb4.polymer.blocks.api.BlockModelType;
 import eu.pb4.polymer.blocks.api.BlockResourceCreator;
 import eu.pb4.polymer.blocks.api.PolymerBlockModel;
@@ -15,6 +16,7 @@
 import net.minecraft.registry.RegistryKey;
 import net.minecraft.registry.RegistryKeys;
 import net.minecraft.util.Identifier;
+import net.minecraft.util.Unit;
 import xyz.nucleoid.plasmid.api.game.GameType;
 import xyz.nucleoid.plasmid.api.game.common.GameResourcePack;
 
@@ -45,6 +47,7 @@ public class TestInitializer implements ModInitializer {
     @Override
     public void onInitialize() {
         GameType.register(Identifier.of(ID, "test"), TestConfig.CODEC, TestGame::open);
+        GameType.register(Identifier.of(ID, "persistent"), MapCodec.unit(Unit.INSTANCE), PersistentGame::open);
         GameType.register(Identifier.of(ID, "no_join"), TestConfig.CODEC, PlayerlessGame::open);
         GameType.register(Identifier.of(ID, "test_rp"), TestConfig.CODEC, TestGameWithResourcePack::open);
         GameType.register(Identifier.of(ID, "jank"), TestConfig.CODEC, JankGame::open);

src/testmod/resources/data/testmod/plasmid/game/persistent.json

@@ -0,0 +1,5 @@
+{
+  "type": "testmod:persistent",
+  "icon": "dirt",
+  "description": []
+}