From cc2febcb5cc983867ac7e0d68d21a46cf6fe9f11 Mon Sep 17 00:00:00 2001
From: Acuadragon100 <8165958-acuadragon100@users.noreply.gitlab.com>
Date: Sun, 3 May 2026 17:58:13 +0200
Subject: [PATCH] Fix current level unloading on the client.

---
 .../core/world/DhClientServerWorld.java       | 20 +++++++++++++------
 .../core/world/DhClientWorld.java             |  6 ++++--
 .../core/world/DhServerWorld.java             |  6 ++++--
 .../distanthorizons/core/world/IDhWorld.java  |  2 +-
 4 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/core/src/main/java/com/seibel/distanthorizons/core/world/DhClientServerWorld.java b/core/src/main/java/com/seibel/distanthorizons/core/world/DhClientServerWorld.java
index 937ed97a2..e943e8772 100644
--- a/core/src/main/java/com/seibel/distanthorizons/core/world/DhClientServerWorld.java
+++ b/core/src/main/java/com/seibel/distanthorizons/core/world/DhClientServerWorld.java
@@ -37,7 +37,7 @@ import java.util.concurrent.CompletableFuture;
 
 public class DhClientServerWorld extends AbstractDhServerWorld<DhClientServerLevel> implements IDhClientWorld
 {
-	private final Set<DhClientServerLevel> dhLevels = Collections.synchronizedSet(new HashSet<>());
+	private final Map<DhClientServerLevel, Set<ILevelWrapper>> dhLevels = Collections.synchronizedMap(new HashMap<>());
 	
 	private final Timer clientTickTimer = TimerUtil.CreateTimer("ClientTickTimer");
 	
@@ -57,7 +57,7 @@ public class DhClientServerWorld extends AbstractDhServerWorld<DhClientServerLev
 			@Override 
 			public void run()
 			{
-				DhClientServerWorld.this.dhLevels.forEach(DhClientServerLevel::clientTick);
+				DhClientServerWorld.this.dhLevels.keySet().forEach(DhClientServerLevel::clientTick);
 			}
 		}, 0, IDhClientWorld.TICK_RATE_IN_MS);
 	}
@@ -78,7 +78,7 @@ public class DhClientServerWorld extends AbstractDhServerWorld<DhClientServerLev
 				try
 				{
 					DhClientServerLevel level = new DhClientServerLevel(this.saveStructure, (IServerLevelWrapper) levelWrapper, this.getServerPlayerStateManager());
-					this.dhLevels.add(level);
+					this.dhLevels.computeIfAbsent(level, k -> Collections.synchronizedSet(new HashSet<>()));
 					ApiEventInjector.INSTANCE.fireAllEvents(DhApiLevelLoadEvent.class, new DhApiLevelLoadEvent.EventParam(wrapper));
 					return level;
 				}
@@ -119,13 +119,14 @@ public class DhClientServerWorld extends AbstractDhServerWorld<DhClientServerLev
 				
 				level.startRenderer();
 				clientLevelWrapper.setDhLevel(level);
+				dhLevels.get(level).add(wrapper);
 				return level;
 			});
 		}
 	}
 	
 	@Override
-	public void unloadLevel(@NotNull ILevelWrapper wrapper)
+	public boolean unloadLevel(@NotNull ILevelWrapper wrapper)
 	{
 		if (this.dhLevelByLevelWrapper.containsKey(wrapper))
 		{
@@ -143,11 +144,18 @@ public class DhClientServerWorld extends AbstractDhServerWorld<DhClientServerLev
 				// If the level wrapper is a Client Level Wrapper, then that means the client side leaves the level,
 				// but note that the server side still has the level loaded. So, we don't want to unload the level,
 				// we just want to stop rendering it.
-				this.dhLevelByLevelWrapper.remove(wrapper).stopRenderer(); // Ignore resource warning. The level obj is referenced elsewhere.
+				DhClientServerLevel level = this.dhLevelByLevelWrapper.remove(wrapper); // Ignore resource warning. The level obj is referenced elsewhere.
+				Set<ILevelWrapper> wrappers = dhLevels.get(level);
+				wrappers.remove(wrapper);
+				if (wrappers.isEmpty()) {
+					level.stopRenderer();
+				}
 				wrapper.onUnload(); // We still want to unload the wrapper though.
 			}
 			ApiEventInjector.INSTANCE.fireAllEvents(DhApiLevelUnloadEvent.class, new DhApiLevelUnloadEvent.EventParam(wrapper));
+			return true;
 		}
+		return false;
 	}
 	
 	
@@ -165,7 +173,7 @@ public class DhClientServerWorld extends AbstractDhServerWorld<DhClientServerLev
 		synchronized (this.dhLevels)
 		{
 			// close each level
-			for (DhClientServerLevel level : this.dhLevels)
+			for (DhClientServerLevel level : this.dhLevels.keySet())
 			{
 				// level wrapper shouldn't be null, but just in case
 				IServerLevelWrapper serverLevelWrapper = level.getServerLevelWrapper();
diff --git a/core/src/main/java/com/seibel/distanthorizons/core/world/DhClientWorld.java b/core/src/main/java/com/seibel/distanthorizons/core/world/DhClientWorld.java
index a6836592e..260feca6d 100644
--- a/core/src/main/java/com/seibel/distanthorizons/core/world/DhClientWorld.java
+++ b/core/src/main/java/com/seibel/distanthorizons/core/world/DhClientWorld.java
@@ -132,11 +132,11 @@ public class DhClientWorld extends AbstractDhWorld implements IDhClientWorld
 	public int getLoadedLevelCount() { return this.levels.size(); }
 	
 	@Override
-	public void unloadLevel(@NotNull ILevelWrapper wrapper)
+	public boolean unloadLevel(@NotNull ILevelWrapper wrapper)
 	{
 		if (!(wrapper instanceof IClientLevelWrapper))
 		{
-			return;
+			return false;
 		}
 		
 		if (this.levels.containsKey(wrapper))
@@ -145,7 +145,9 @@ public class DhClientWorld extends AbstractDhWorld implements IDhClientWorld
 			wrapper.onUnload();
 			this.levels.remove(wrapper).close();
 			ApiEventInjector.INSTANCE.fireAllEvents(DhApiLevelUnloadEvent.class, new DhApiLevelUnloadEvent.EventParam(wrapper));
+			return true;
 		}
+		return false;
 	}
 	
 	@Override
diff --git a/core/src/main/java/com/seibel/distanthorizons/core/world/DhServerWorld.java b/core/src/main/java/com/seibel/distanthorizons/core/world/DhServerWorld.java
index f19d81381..4511b6ee7 100644
--- a/core/src/main/java/com/seibel/distanthorizons/core/world/DhServerWorld.java
+++ b/core/src/main/java/com/seibel/distanthorizons/core/world/DhServerWorld.java
@@ -85,11 +85,11 @@ public class DhServerWorld extends AbstractDhServerWorld<DhServerLevel>
 	}
 	
 	@Override
-	public void unloadLevel(@NotNull ILevelWrapper wrapper)
+	public boolean unloadLevel(@NotNull ILevelWrapper wrapper)
 	{
 		if (!(wrapper instanceof IServerLevelWrapper))
 		{
-			return;
+			return false;
 		}
 		
 		if (this.dhLevelByLevelWrapper.containsKey(wrapper))
@@ -97,7 +97,9 @@ public class DhServerWorld extends AbstractDhServerWorld<DhServerLevel>
 			wrapper.onUnload();
 			this.dhLevelByLevelWrapper.remove(wrapper).close();
 			ApiEventInjector.INSTANCE.fireAllEvents(DhApiLevelUnloadEvent.class, new DhApiLevelUnloadEvent.EventParam(wrapper));
+			return true;
 		}
+		return false;
 	}
 	
 	@Override
diff --git a/core/src/main/java/com/seibel/distanthorizons/core/world/IDhWorld.java b/core/src/main/java/com/seibel/distanthorizons/core/world/IDhWorld.java
index f99db3c2b..c981c25cb 100644
--- a/core/src/main/java/com/seibel/distanthorizons/core/world/IDhWorld.java
+++ b/core/src/main/java/com/seibel/distanthorizons/core/world/IDhWorld.java
@@ -49,6 +49,6 @@ public interface IDhWorld extends Closeable
 	Iterable<? extends IDhLevel> getAllLoadedLevels();
 	int getLoadedLevelCount();
 	
-	void unloadLevel(@NotNull ILevelWrapper levelWrapper);
+	boolean unloadLevel(@NotNull ILevelWrapper levelWrapper);
 	
 }