Improve logging and potentially fix a few substring crashes

src/main/java/com/seibel/lod/core/api/ClientApi.java

@@ -27,6 +27,7 @@ import java.util.List;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
 
+import com.seibel.lod.core.handlers.LodDimensionFileHelper;
 import org.lwjgl.glfw.GLFW;
 
 import com.seibel.lod.core.ModInfo;
@@ -100,11 +101,17 @@ public class ClientApi
 	public boolean rendererDisabledBecauseOfExceptions = false;
 	
 	
+	
+	
+	
 	private ClientApi()
 	{
 		
 	}
 	
+	
+	
+	
 	private void flushSpamLoggersState() {
 		synchronized(spamReducedLoggers) {
 			spamReducedLoggers.removeIf((logger) -> logger.get()==null);
@@ -158,9 +165,13 @@ public class ClientApi
 				return;
 			
 			IWorldWrapper world = MC.getWrappedClientWorld();
-			if (world == null) return;
+			if (world == null)
+				return;
 			LodDimension lodDim = ApiShared.lodWorld.getLodDimension(world.getDimensionType());
 			
+			// Make sure the player's data is up-to-date
+			LodDimensionFileHelper.updatePlayerData();
+			
 			// Make the LodDim if it does not exist
 			if (lodDim == null)
 			{

src/main/java/com/seibel/lod/core/api/EventApi.java

@@ -20,6 +20,7 @@
 package com.seibel.lod.core.api;
 
 import com.seibel.lod.core.api.ClientApi.LagSpikeCatcher;
+import com.seibel.lod.core.handlers.LodDimensionFileHelper;
 import com.seibel.lod.core.objects.opengl.builders.lodBuilding.LodBuilder;
 import com.seibel.lod.core.objects.opengl.builders.worldGeneration.BatchGenerator;
 import com.seibel.lod.core.enums.WorldType;
@@ -59,6 +60,9 @@ public class EventApi
 	 */
 	private boolean recalculateWidths = false;
 	
+	private boolean isCurrentlyOnSinglePlayerServer = false;
+	
+	
 	private EventApi()
 	{
 	
@@ -113,8 +117,6 @@ public class EventApi
 		ApiShared.lodWorld.saveAllDimensions(false); // Do an async save.
 	}
 	
-	private boolean isCurrentlyOnSinglePlayerServer = false;
-	
 	/** This is also called when a new dimension loads */
 	public void worldLoadEvent(IWorldWrapper world)
 	{

src/main/java/com/seibel/lod/core/handlers/LodDimensionFileHandler.java

@@ -33,6 +33,7 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantLock;
 
+import com.seibel.lod.core.ModInfo;
 import com.seibel.lod.core.api.ApiShared;
 import org.apache.commons.compress.compressors.xz.XZCompressorInputStream;
 import org.apache.commons.compress.compressors.xz.XZCompressorOutputStream;
@@ -48,6 +49,8 @@ import com.seibel.lod.core.util.LodThreadFactory;
 import com.seibel.lod.core.util.LodUtil;
 import com.seibel.lod.core.util.SpamReducedLogger;
 import com.seibel.lod.core.util.UnitBytes;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 
 /**
@@ -61,6 +64,8 @@ import com.seibel.lod.core.util.UnitBytes;
  */
 public class LodDimensionFileHandler
 {
+	public static final Logger LOGGER = LogManager.getLogger("LodDimensionFileHandler");
+	
 	public static final boolean ENABLE_SAVE_THREAD_LOGGING = true;
 	public static final boolean ENABLE_SAVE_REGION_LOGGING = false;
 	
@@ -147,26 +152,26 @@ public class LodDimensionFileHandler
 							subFile.getName().equals(DistanceGenerationMode.BIOME_ONLY.toString()) ||
 							subFile.getName().equals(DistanceGenerationMode.NONE.toString()))
 					{
-						ApiShared.LOGGER.info("Noticed old save structure files. Starting merge process...");
+						LOGGER.info("Noticed old save structure files. Starting merge process...");
 						LodDimensionOldFileStructureHandler oldFileStructHandler = new LodDimensionOldFileStructureHandler(this);
 						if (mergeOldFileLock.tryLock())
 						{
 							// I got the lock to merge file.
-							ApiShared.LOGGER.info("Updating VerticalQuality LOW...");
+							LOGGER.info("Updating VerticalQuality LOW...");
 							oldFileStructHandler.mergeOldFileStructureForVertQuality(VerticalQuality.LOW);
-							ApiShared.LOGGER.info("Updating VerticalQuality MEDIUM...");
+							LOGGER.info("Updating VerticalQuality MEDIUM...");
 							oldFileStructHandler.mergeOldFileStructureForVertQuality(VerticalQuality.MEDIUM);
-							ApiShared.LOGGER.info("Updating VerticalQuality HIGH...");
+							LOGGER.info("Updating VerticalQuality HIGH...");
 							oldFileStructHandler.mergeOldFileStructureForVertQuality(VerticalQuality.HIGH);
-							ApiShared.LOGGER.info("Update completed.");
+							LOGGER.info("Update completed.");
 						}
 						else
 						{
-							// Someone is already doing it. I just need to wait until he is done.
+							// Someone is already doing it. I just need to wait until they are done.
 							mergeOldFileLock.lock();
 							mergeOldFileLock.unlock();
 						}
-						ApiShared.LOGGER.info("Merge process completed.");
+						LOGGER.info("Merge process completed.");
 						return;
 					}
 				}
@@ -238,7 +243,7 @@ public class LodDimensionFileHandler
 					// close the reader and delete the file.
 					inputStream.close();
 					file.delete();
-					ApiShared.LOGGER.info("Outdated LOD region file for region: (" + regionX + "," + regionZ + ")"
+					LOGGER.info("Outdated LOD region file for region: (" + regionX + "," + regionZ + ")"
 							+ " version found: " + fileVersion
 							+ ", version requested: " + LOD_SAVE_FILE_VERSION
 							+ ". File has been deleted.");
@@ -251,7 +256,7 @@ public class LodDimensionFileHandler
 					// close the reader and ignore the file, we don't
 					// want to accidentally delete anything the user may want.
 					inputStream.close();
-					ApiShared.LOGGER.info("Newer LOD region file for region: (" + regionX + "," + regionZ + ")"
+					LOGGER.info("Newer LOD region file for region: (" + regionX + "," + regionZ + ")"
 							+ " version found: " + fileVersion
 							+ ", version requested: " + LOD_SAVE_FILE_VERSION
 							+ " this region will not be written to in order to protect the newer file.");
@@ -260,7 +265,7 @@ public class LodDimensionFileHandler
 				}
 				else if (fileVersion < LOD_SAVE_FILE_VERSION)
 				{
-					ApiShared.LOGGER.debug("Old LOD region file for region: (" + regionX + "," + regionZ + ")"
+					LOGGER.debug("Old LOD region file for region: (" + regionX + "," + regionZ + ")"
 							+ " version found: " + fileVersion
 							+ ", version requested: " + LOD_SAVE_FILE_VERSION
 							+ ". File will be loaded and updated to new format in next save.");
@@ -283,7 +288,7 @@ public class LodDimensionFileHandler
 			}
 			catch (IOException ioEx)
 			{
-				ApiShared.LOGGER.error("LOD file read error. Unable to read xz compressed file [" + file + "]: ", ioEx);
+				LOGGER.error("LOD file read error. Unable to read xz compressed file [" + file + "]: ", ioEx);
 				region.addLevelContainer(new VerticalLevelContainer(tempDetailLevel));
 			}
 		} // for each detail level
@@ -303,7 +308,7 @@ public class LodDimensionFileHandler
 				FILE_NAME_PREFIX + "." + posX + "." + posZ + FILE_EXTENSION);
 		if (file.exists())
 		{
-			ApiShared.LOGGER.warn("LOD file write warn. Unable to write [" + file + "] because the newer version file already exist! Skipping this position...");
+			LOGGER.warn("LOD file write warn. Unable to write [" + file + "] because the newer version file already exist! Skipping this position...");
 			return;
 		}
 		if (!file.getParentFile().exists())
@@ -314,7 +319,7 @@ public class LodDimensionFileHandler
 		}
 		catch (IOException e)
 		{
-			ApiShared.LOGGER.error("LOD file write error. Unable to create parent directory for [" + file + "]: ", e);
+			LOGGER.error("LOD file write error. Unable to create parent directory for [" + file + "]: ", e);
 			return;
 		}
 		try (FileOutputStream fileOutStream = new FileOutputStream(file))
@@ -330,7 +335,7 @@ public class LodDimensionFileHandler
 		}
 		catch (IOException e)
 		{
-			ApiShared.LOGGER.error("LOD file write error. Unable to write to temp file [" + file + "]: ", e);
+			LOGGER.error("LOD file write error. Unable to write to temp file [" + file + "]: ", e);
 		}
 	}
 	
@@ -367,7 +372,7 @@ public class LodDimensionFileHandler
 			LevelContainer[] container = r.debugGetDataContainers().clone();
 			if (container == null || container.length != LodUtil.DETAIL_OPTIONS)
 			{
-				ApiShared.LOGGER.warn("DumpRamUsage encountered an invalid region!");
+				LOGGER.warn("DumpRamUsage encountered an invalid region!");
 				continue;
 			}
 			for (int i = 0; i < LodUtil.DETAIL_OPTIONS; i++)
@@ -395,6 +400,7 @@ public class LodDimensionFileHandler
 	/** Save all dirty regions in this LodDimension to file */
 	public void saveDirtyRegionsToFile(boolean blockUntilFinished)
 	{
+		// determine the regions to save
 		for (int i = 0; i < lodDimension.getWidth(); i++)
 		{
 			for (int j = 0; j < lodDimension.getWidth(); j++)
@@ -402,28 +408,34 @@ public class LodDimensionFileHandler
 				LodRegion r = lodDimension.getRegionByArrayIndex(i, j);
 				
 				// FIXME: Note that the isWriting is a crude attempt at syncing. It won't work.
-				// It just reduce the chance of race condition
+				// It just reduces the chance of a race condition
 				if (r != null && r.needSaving)
 				{
 					regionToSave.put(r.getRegionPos(), r);
 				}
 			}
 		}
+		
+		// save the dimension data
+		LodDimensionFileHelper.saveDimensionPlayerData(this.dimensionDataSaveFolder);
 		trySaveRegionsToBeSaved();
+		
+		// wait for the saving to finish if requested
 		if (blockUntilFinished)
 		{
 			if (ENABLE_SAVE_THREAD_LOGGING)
-				ApiShared.LOGGER.info("Blocking until lod file save finishes!");
+				LOGGER.info("Blocking until lod file save finishes!");
+			
 			try
 			{
 				fileWritingThreadPool.shutdown();
 				boolean worked = fileWritingThreadPool.awaitTermination(30, TimeUnit.SECONDS);
 				if (!worked)
-					ApiShared.LOGGER.error("File writing timed out! File data may not be saved correctly and may cause corruptions!!!");
+					LOGGER.error("File writing timed out! File data may not be saved correctly and may cause corruptions!!!");
 			}
 			catch (InterruptedException e)
 			{
-				ApiShared.LOGGER.error("File writing wait is interrupted! File data may not be saved correctly and may cause corruptions!!!: ", e);
+				LOGGER.error("File writing wait is interrupted! File data may not be saved correctly and may cause corruptions!!!: ", e);
 			}
 			finally
 			{
@@ -461,7 +473,7 @@ public class LodDimensionFileHandler
 			throw new ConcurrentModificationException("WriterMain Triggered but the thead state is not started!?");
 		
 		if (ENABLE_SAVE_THREAD_LOGGING)
-			ApiShared.LOGGER.info("Lod File Writer started. To-be-written-regions: " + regionToSave.size());
+			LOGGER.info("Lod File Writer started. To-be-written-regions: " + regionToSave.size());
 		
 		Instant start = Instant.now();
 		// Note: Since regionToSave is a ConcurrentHashMap, and the .values() return one that support concurrency,
@@ -481,16 +493,16 @@ public class LodDimensionFileHandler
 					r.needSaving = false;
 					Instant i = Instant.now();
 					if (ENABLE_SAVE_REGION_LOGGING)
-						ApiShared.LOGGER.info("Lod: Saving Region " + r.getRegionPos());
+						LOGGER.info("Lod: Saving Region " + r.getRegionPos());
 					saveRegionToFile(r);
 					Instant j = Instant.now();
 					Duration d = Duration.between(i, j);
 					if (ENABLE_SAVE_REGION_LOGGING)
-						ApiShared.LOGGER.info("Lod: Region " + r.getRegionPos() + " save finish. Took " + d);
+						LOGGER.info("Lod: Region " + r.getRegionPos() + " save finish. Took " + d);
 				}
 				catch (Exception e)
 				{
-					ApiShared.LOGGER.error("Lod: UNCAUGHT exception when saving region " + r.getRegionPos() + ": ", e);
+					LOGGER.error("Lod: UNCAUGHT exception when saving region " + r.getRegionPos() + ": ", e);
 				}
 				finally
 				{
@@ -501,7 +513,7 @@ public class LodDimensionFileHandler
 		Instant end = Instant.now();
 		
 		if (ENABLE_SAVE_THREAD_LOGGING)
-			ApiShared.LOGGER.info("Lod File Writer completed. Took " + Duration.between(start, end));
+			LOGGER.info("Lod File Writer completed. Took " + Duration.between(start, end));
 		
 		// Use Memory order Release to release any memory changes on setting this boolean
 		// (Corresponding call is the this::saveRegions(...)::...compareAndExchangeAcquire(false, true);)
@@ -525,7 +537,7 @@ public class LodDimensionFileHandler
 			// Get the old file
 			File oldFile = getRegionFile(region.regionPosX, region.regionPosZ, detailLevel, region.getVerticalQuality());
 			if (ENABLE_SAVE_REGION_LOGGING)
-				ApiShared.LOGGER.debug("saving region [" + region.regionPosX + ", " + region.regionPosZ + "] detail " + detailLevel + " to file.");
+				LOGGER.debug("saving region [" + region.regionPosX + ", " + region.regionPosZ + "] detail " + detailLevel + " to file.");
 			
 			boolean isFileFullyGened = false;
 			// make sure the file and folder exists
@@ -542,7 +554,7 @@ public class LodDimensionFileHandler
 				}
 				catch (IOException e)
 				{
-					ApiShared.LOGGER.error("LOD file write error. Unable to create parent directory for [" + oldFile + "] error [" + e.getMessage() + "]: ");
+					LOGGER.error("LOD file write error. Unable to create parent directory for [" + oldFile + "] error [" + e.getMessage() + "]: ");
 					e.printStackTrace();
 					continue;
 				}
@@ -564,7 +576,7 @@ public class LodDimensionFileHandler
 				}
 				catch (IOException e)
 				{
-					ApiShared.LOGGER.warn("LOD file write warning. Unable to read existing file [" + oldFile + "] version. Treating it as latest version. [" + e.getMessage() + "]: ");
+					LOGGER.warn("LOD file write warning. Unable to read existing file [" + oldFile + "] version. Treating it as latest version. [" + e.getMessage() + "]: ");
 					e.printStackTrace();
 				}
 				
@@ -598,7 +610,7 @@ public class LodDimensionFileHandler
 					// existing file is complete while new one is only partially generate
 					// this can happen is for some reason loading failed
 					// this doesn't fix the bug, but at least protects old data
-					ApiShared.LOGGER.error("LOD file write error. Attempted to overwrite complete region with incomplete one [" + oldFile + "]");
+					LOGGER.error("LOD file write error. Attempted to overwrite complete region with incomplete one [" + oldFile + "]");
 					try
 					{
 						tempFile.delete();
@@ -612,7 +624,7 @@ public class LodDimensionFileHandler
 			}
 			catch (IOException e)
 			{
-				ApiShared.LOGGER.error("LOD file write error. Unable to write to temp file [" + tempFile + "]: ", e);
+				LOGGER.error("LOD file write error. Unable to write to temp file [" + tempFile + "]: ", e);
 				continue;
 			}
 			
@@ -623,7 +635,7 @@ public class LodDimensionFileHandler
 			}
 			catch (IOException e)
 			{
-				ApiShared.LOGGER.error("LOD file write error. Unable to update file [" + oldFile + "]: ", e);
+				LOGGER.error("LOD file write error. Unable to update file [" + oldFile + "]: ", e);
 			}
 		}
 	}
@@ -645,7 +657,7 @@ public class LodDimensionFileHandler
 		}
 		catch (IOException e)
 		{
-			ApiShared.LOGGER.warn("Unable to get the base save file path. One possible cause is that"
+			LOGGER.warn("Unable to get the base save file path. One possible cause is that"
 					+ " the process failed to read the current path location due to security configs.");
 			throw new RuntimeException("DistantHorizons Get Save File Path Failure");
 		}

src/main/java/com/seibel/lod/core/handlers/LodDimensionFileHelper.java

@@ -1,8 +1,9 @@
 package com.seibel.lod.core.handlers;
 
+import com.electronwill.nightconfig.core.file.CommentedFileConfig;
 import com.seibel.lod.core.api.ApiShared;
-import com.seibel.lod.core.builders.lodBuilding.LodBuilder;
-import com.seibel.lod.core.builders.lodBuilding.LodBuilderConfig;
+import com.seibel.lod.core.objects.opengl.builders.lodBuilding.LodBuilder;
+import com.seibel.lod.core.objects.opengl.builders.lodBuilding.LodBuilderConfig;
 import com.seibel.lod.core.enums.config.DistanceGenerationMode;
 import com.seibel.lod.core.enums.config.VerticalQuality;
 import com.seibel.lod.core.handlers.dependencyInjection.SingletonHandler;
@@ -10,6 +11,8 @@ import com.seibel.lod.core.objects.lod.LodDimension;
 import com.seibel.lod.core.objects.lod.LodRegion;
 import com.seibel.lod.core.objects.lod.RegionPos;
 import com.seibel.lod.core.util.LodUtil;
+import com.seibel.lod.core.wrapperInterfaces.IWrapperFactory;
+import com.seibel.lod.core.wrapperInterfaces.block.AbstractBlockPosWrapper;
 import com.seibel.lod.core.wrapperInterfaces.chunk.AbstractChunkPosWrapper;
 import com.seibel.lod.core.wrapperInterfaces.chunk.IChunkWrapper;
 import com.seibel.lod.core.wrapperInterfaces.config.ILodConfigWrapperSingleton;
@@ -30,9 +33,15 @@ public class LodDimensionFileHelper
 {
 	private static final IMinecraftClientWrapper MC = SingletonHandler.get(IMinecraftClientWrapper.class);
 	private static final ILodConfigWrapperSingleton CONFIG = SingletonHandler.get(ILodConfigWrapperSingleton.class);
+	private static final IWrapperFactory FACTORY = SingletonHandler.get(IWrapperFactory.class);
 	
 	/** Increasing this will increase accuracy but increase calculation time */
-	private static final VerticalQuality VERTICAL_QUALITY_TO_TEST_WITH = VerticalQuality.LOW;
+	private static final VerticalQuality VERTICAL_QUALITY_TO_TEST_WITH = VerticalQuality.MEDIUM;
+	
+	
+	private static LodDimensionFileHelper.PlayerData PLAYER_DATA = new LodDimensionFileHelper.PlayerData(MC);
+	private static LodDimensionFileHelper.PlayerData FIRST_SEEN_PLAYER_DATA = null;
+	
 	
 	
 	/**
@@ -42,13 +51,21 @@ public class LodDimensionFileHelper
 	 * @return the new or existing folder for this dimension, null if there was a problem
 	 * @throws IOException if the folder doesn't exist or can't be accessed
 	 */
-	public static File determineSaveFolder() throws IOException
+	public static File determineSubDimensionFolder() throws IOException
 	{
+		if (FIRST_SEEN_PLAYER_DATA == null)
+		{
+			FIRST_SEEN_PLAYER_DATA = PLAYER_DATA;
+			PLAYER_DATA = new LodDimensionFileHelper.PlayerData(MC);
+		}
+		
+		
 		// relevant positions
-		AbstractChunkPosWrapper playerChunkPos = MC.getPlayerChunkPos();
+		AbstractChunkPosWrapper playerChunkPos = FACTORY.createChunkPos(FIRST_SEEN_PLAYER_DATA.playerBlockPos);
 		int startingBlockPosX = playerChunkPos.getMinBlockX();
 		int startingBlockPosZ = playerChunkPos.getMinBlockZ();
-		RegionPos playerRegionPos = new RegionPos(MC.getPlayerChunkPos());
+		RegionPos playerRegionPos = new RegionPos(playerChunkPos);
+		
 		
 		// chunk from the newly loaded dimension
 		IChunkWrapper newlyLoadedChunk = MC.getWrappedClientWorld().tryGetChunk(playerChunkPos);
@@ -56,7 +73,7 @@ public class LodDimensionFileHelper
 		if (!LodDimensionFileHelper.CanDetermineDimensionFolder(newlyLoadedChunk))
 			return null;
 		
-		// create a temporary dimension to store the new LOD
+		// create a temporary dimension to store the test LOD
 		LodDimension newlyLoadedDim = new LodDimension(MC.getCurrentDimension(), null, 1);
 		newlyLoadedDim.move(playerRegionPos);
 		newlyLoadedDim.regions.set(playerRegionPos.x, playerRegionPos.z, new LodRegion(LodUtil.BLOCK_DETAIL_LEVEL, playerRegionPos, VERTICAL_QUALITY_TO_TEST_WITH));
@@ -66,6 +83,12 @@ public class LodDimensionFileHelper
 		if (!lodGenerated)
 			return null;
 		
+		
+		// log the start of this attempt
+		ApiShared.LOGGER.info("Attempting to determine sub-dimension for [" + MC.getCurrentDimension().getDimensionName() + "]");
+		ApiShared.LOGGER.info("First seen player block pos in dimension: [" + FIRST_SEEN_PLAYER_DATA.playerBlockPos.getX() + "," + FIRST_SEEN_PLAYER_DATA.playerBlockPos.getY() + "," + FIRST_SEEN_PLAYER_DATA.playerBlockPos.getZ() + "]");
+		
+		
 		// new chunk data
 		long[][][] newChunkData = new long[LodUtil.CHUNK_WIDTH][LodUtil.CHUNK_WIDTH][];
 		for (int x = 0; x < LodUtil.CHUNK_WIDTH; x++)
@@ -77,9 +100,6 @@ public class LodDimensionFileHelper
 			}
 		}
 		boolean newChunkHasData = isDataEmpty(newChunkData);
-//		String message = "new chunk data " + (newChunkHasData ? newChunkData[0][0][0] : "[NULL]");
-//		MC.sendChatMessage(message);
-//		ApiShared.LOGGER.info(message);
 		
 		// check if the chunk is actually empty
 		if (!newChunkHasData)
@@ -88,16 +108,16 @@ public class LodDimensionFileHelper
 			{
 				// the chunk isn't empty but the LOD is...
 				
-//				String message = "Error: the chunk at (" + playerChunkPos.getX() + "," + playerChunkPos.getZ() + ") has a height of [" + newlyLoadedChunk.getHeight() + "] but the LOD generated is empty!";
-//				MC.sendChatMessage(message);
-//				ApiShared.LOGGER.info(message);
+				String message = "Error: the chunk at (" + playerChunkPos.getX() + "," + playerChunkPos.getZ() + ") has a height of [" + newlyLoadedChunk.getHeight() + "] but the LOD generated is empty!";
+				MC.sendChatMessage(message);
+				ApiShared.LOGGER.error(message);
 				return null;
 			}
 			else
 			{
-//				String message = "The chunk at (" + playerChunkPos.getX() + "," + playerChunkPos.getZ() + ") is empty.";
+				String message = "Warning: The chunk at (" + playerChunkPos.getX() + "," + playerChunkPos.getZ() + ") is empty.";
 //				MC.sendChatMessage(message);
-//				ApiShared.LOGGER.info(message);
+				ApiShared.LOGGER.warn(message);
 			}
 		}
 		
@@ -114,21 +134,23 @@ public class LodDimensionFileHelper
 				// create the directory since it doesn't exist
 				dimensionFolder.mkdirs();
 			}
-			else
-			{
-				return null;
-			}
 		}
 		
+		// TODO move any old files if they exist
+		
+		
 		
 		// compare each world with the newly loaded one
 		File mostSimilarWorldFolder = null;
 		int mostEqualLines = 0;
-		boolean oneDimensionIsValid = false;
+		double highestEqualityPercent = 0.0;
 		double minimumSimilarityRequired = CONFIG.client().multiplayer().getMultiDimensionRequiredSimilarity();
 		
+		ApiShared.LOGGER.info("Known Sub Dimensions: [" + dimensionFolder.listFiles().length + "]");
 		for (File testDimFolder : dimensionFolder.listFiles())
 		{
+			ApiShared.LOGGER.info("Testing sub dimension: [" + LodUtil.shortenString(testDimFolder.getName(), 8) + "]");
+			
 			// get a LOD from this dimension folder
 			LodDimension tempLodDim = new LodDimension(null, null, 1);
 			tempLodDim.move(playerRegionPos);
@@ -145,15 +167,28 @@ public class LodDimensionFileHelper
 				}
 			}
 			
+			
+			// get the player data for this dimension folder
+			PlayerData testPlayerData = new PlayerData(testDimFolder);
+			ApiShared.LOGGER.info("Last known player pos: [" + testPlayerData.playerBlockPos.getX() + "," + testPlayerData.playerBlockPos.getY() + "," + testPlayerData.playerBlockPos.getZ() + "]");
+			
+			// check if the block positions are close
+			int distance = testPlayerData.playerBlockPos.getManhattanDistance(FIRST_SEEN_PLAYER_DATA.playerBlockPos);
+			ApiShared.LOGGER.info("Player block position distance between saved sub dimension and first seen is [" + distance + "]");
+//			if (distance <= 2) // TODO make this number a config
+//			{
+//				// TODO do something with this information
+//			}
+			
+			
 			// check if the chunk is actually empty
 			if (!isDataEmpty(newChunkData))
 			{
-//				String message = "The test chunk for dimension folder [" + testDimFolder.getName() + "] and chunk pos (" + playerChunkPos.getX() + "," + playerChunkPos.getZ() + ") is empty. Is that correct?";
+				String message = "The test chunk for dimension folder [" +  LodUtil.shortenString(testDimFolder.getName(), 8) + "] and chunk pos (" + playerChunkPos.getX() + "," + playerChunkPos.getZ() + ") is empty. Is that correct?";
 //				MC.sendChatMessage(message);
-//				ApiShared.LOGGER.info(message);
+				ApiShared.LOGGER.info(message);
 				continue;
 			}
-			oneDimensionIsValid = true;
 			
 			
 			// compare the two LODs
@@ -177,28 +212,31 @@ public class LodDimensionFileHelper
 			
 			// determine if this world is closer to the newly loaded world
 			double percentEqual = (double) equalLines / (double) totalLineCount;
-			if (equalLines > mostEqualLines && percentEqual >= minimumSimilarityRequired)
+			if (equalLines > mostEqualLines)
 			{
 				mostEqualLines = equalLines;
-				mostSimilarWorldFolder = testDimFolder;
+				highestEqualityPercent = percentEqual;
+				
+				if (percentEqual >= minimumSimilarityRequired)
+				{
+					mostSimilarWorldFolder = testDimFolder;
+				}
 			}
-//			String message = "test data [" + testDimFolder.getName().substring(0, 6) + "...] " + testChunkData[0][0][0] + " equal lines: " + equalLines + "/" + totalLineCount + " = " + percentEqual;
-//			MC.sendChatMessage(message);
-//			ApiShared.LOGGER.info(message);
+			String message = "Sub dimension [" +  LodUtil.shortenString(testDimFolder.getName(), 8) + "...] is current dimension probability: " +  LodUtil.shortenString(percentEqual + "", 5) + " (" + equalLines + "/" + totalLineCount + ")";
+			MC.sendChatMessage(message);
+			ApiShared.LOGGER.info(message);
 		}
 		
-		
-		if (!oneDimensionIsValid && dimensionFolder.listFiles().length != 0)
-			// all the world folders were empty, and there was at least one world folder that we tested
-			return null;
+		// the first seen player data is no longer needed, the sub dimension has been determined
+		FIRST_SEEN_PLAYER_DATA = null;
 		
 		
 		if (mostSimilarWorldFolder != null)
 		{
 			// we found a world folder that is similar, use it
 			
-			String message = "Dimension folder set to: [" + mostSimilarWorldFolder.getName().substring(0, 8) + "...]";
-//			MC.sendChatMessage(message);
+			String message = "Sub Dimension set to: [" +  LodUtil.shortenString(mostSimilarWorldFolder.getName(), 8) + "...] with an equality of [" + highestEqualityPercent + "]";
+			MC.sendChatMessage(message);
 			ApiShared.LOGGER.info(message);
 			return mostSimilarWorldFolder;
 		}
@@ -207,8 +245,8 @@ public class LodDimensionFileHelper
 			// no world folder was found, create a new one
 			
 			String newId = UUID.randomUUID().toString();
-			String message = "No dimension folder found. Creating a new one with ID: " + newId.substring(0, 8) + "...";
-//			MC.sendChatMessage(message);
+			String message = "No suitable sub dimension found. The highest equality was [" + highestEqualityPercent + "]. Creating a new sub dimension with ID: " + LodUtil.shortenString(newId, 8) + "...";
+			MC.sendChatMessage(message);
 			ApiShared.LOGGER.info(message);
 			return GetDimensionFolder(newlyLoadedDim.dimension, newId);
 		}
@@ -276,4 +314,144 @@ public class LodDimensionFileHelper
 		return false;
 	}
 	
+	
+	
+	
+	
+	
+	
+	private static final String playerDataFileName = "_playerData.toml";
+	
+	private static PlayerData getPlayerData(File worldFolder)
+	{
+		File file = PlayerData.getFileForDimensionFolder(worldFolder);
+		if (!file.exists())
+		{
+			return null;
+		}
+		
+		
+		CommentedFileConfig toml = CommentedFileConfig.builder(file).build();
+		toml.add("path", "test");
+		toml.save();
+		
+		return null;
+	}
+	
+	public static void updatePlayerData()
+	{
+		PLAYER_DATA.updateData(MC);
+	}
+	
+	/** saves any necessary player data to the given world folder */
+	public static void saveDimensionPlayerData(File worldFolder)
+	{
+		// get and create the file and path if they don't exist
+		File file = PlayerData.getFileForDimensionFolder(worldFolder);
+		if (!file.exists())
+		{
+			try
+			{
+				file.getParentFile().mkdirs();
+				file.createNewFile();
+			}
+			catch (IOException e)
+			{
+				ApiShared.LOGGER.error("Unable to save player dimension data for world folder [" + worldFolder.getPath() + "].", e);
+				return;
+			}
+		}
+		
+		// determine the playerData
+		IMinecraftClientWrapper mc = SingletonHandler.get(IMinecraftClientWrapper.class);
+		PlayerData playerdata = new PlayerData(mc);
+		
+		// write the data to file
+		CommentedFileConfig toml = CommentedFileConfig.builder(file).build();
+		playerdata.toTomlFile(toml);
+	}
+	
+	
+	/** Data container for any player data we can use to differentiate one dimension from another. */
+	private static class PlayerData
+	{
+		public static final  IWrapperFactory FACTORY = SingletonHandler.get(IWrapperFactory.class);
+		
+		public static final String PLAYER_BLOCK_POS_X_PATH = "playerBlockPosX";
+		public static final String PLAYER_BLOCK_POS_Y_PATH = "playerBlockPosY";
+		public static final String PLAYER_BLOCK_POS_Z_PATH = "playerBlockPosZ";
+		AbstractBlockPosWrapper playerBlockPos;
+		
+		// not implemented yet
+		public static final String WORLD_SPAWN_POS_X_PATH = "worldSpawnBlockPosX";
+		public static final String WORLD_SPAWN_POS_Y_PATH = "worldSpawnBlockPosY";
+		public static final String WORLD_SPAWN_POS_Z_PATH = "worldSpawnBlockPosZ";
+		/**
+		 * The client world has access to a spawn point, so this should be possible to fill in.
+		 * I'm not sure what this will look like for worlds that don't have a spawn point.
+		 */
+		AbstractBlockPosWrapper worldSpawnPointBlockPos;
+		
+		
+		
+		public PlayerData(IMinecraftClientWrapper mc)
+		{
+			updateData(mc);
+		}
+		
+		public PlayerData(File dimensionFolder)
+		{
+			File file = getFileForDimensionFolder(dimensionFolder);
+			CommentedFileConfig toml = CommentedFileConfig.builder(file).build();
+			
+			// player block pos
+			try
+			{
+				toml.load();
+				
+				// TODO this is crashing...
+				int x = toml.getInt(PLAYER_BLOCK_POS_X_PATH);
+				int y = toml.getInt(PLAYER_BLOCK_POS_Y_PATH);
+				int z = toml.getInt(PLAYER_BLOCK_POS_Z_PATH);
+				this.playerBlockPos = FACTORY.createBlockPos(x, y, z);
+			}
+			catch(Exception e)
+			{
+				ApiShared.LOGGER.error(e.getMessage(), e);
+			}
+		}
+		
+		
+		
+		public static File getFileForDimensionFolder(File file)
+		{
+			return new File(file.getPath() + File.separatorChar + playerDataFileName);
+		}
+		
+		
+		/**  */
+		public void updateData(IMinecraftClientWrapper mc)
+		{
+			this.playerBlockPos = mc.getPlayerBlockPos();
+		}
+		
+		/** Writes everything from this object to the file given. */
+		public void toTomlFile(CommentedFileConfig toml)
+		{
+			// player block pos
+			toml.add(PLAYER_BLOCK_POS_X_PATH, playerBlockPos.getX());
+			toml.add(PLAYER_BLOCK_POS_Y_PATH, playerBlockPos.getY());
+			toml.add(PLAYER_BLOCK_POS_Z_PATH, playerBlockPos.getZ());
+			
+			
+			toml.save();
+		}
+		
+		
+		@Override
+		public String toString()
+		{
+			return "PlayerBlockPos: [" + playerBlockPos.getX() + "," + playerBlockPos.getY() + "," + playerBlockPos.getZ() + "]";
+		}
+	}
 }

src/main/java/com/seibel/lod/core/objects/lod/LodDimension.java

@@ -131,12 +131,12 @@ public class LodDimension
 		
 		
 		// run asynchronously since this could take a while
-		new Thread(() ->
+		Thread thread =new Thread(() ->
 		{
 			try
 			{
 				// attempt to get the file handler
-				File saveDir = LodDimensionFileHelper.determineSaveFolder();
+				File saveDir = LodDimensionFileHelper.determineSubDimensionFolder();
 				if (saveDir == null)
 					return;
 				
@@ -155,7 +155,9 @@ public class LodDimension
 				// make sure we unlock this method
 				this.determiningWorldFolder = false;
 			}
-		}).start();
+		});
+		thread.setName("Sub-Dimension-Finder");
+		thread.start();
 	}
 	
 	

src/main/java/com/seibel/lod/core/util/LodUtil.java

@@ -414,4 +414,22 @@ public class LodUtil
 	public static void checkInterruptsUnchecked() {
 		if (Thread.interrupted()) throw new RuntimeException(new InterruptedException());
 	}
+	
+	
+	/**
+	 * Returns a shortened version of the given string that is no longer than maxLength. <br>
+	 * If null returns the empty string.
+	 */
+	public static String shortenString(String str, int maxLength)
+	{
+		if (str == null)
+		{
+			return "";
+		}
+		else
+		{
+			return str.substring(0, Math.min(str.length(), maxLength));
+		}
+	}
+	
 }

src/main/java/com/seibel/lod/core/wrapperInterfaces/block/AbstractBlockPosWrapper.java

@@ -45,4 +45,10 @@ public abstract class AbstractBlockPosWrapper
 	
 	/** returns itself */
 	public abstract AbstractBlockPosWrapper offset(int x, int y, int z);
+	
+	
+	public int getManhattanDistance(AbstractBlockPosWrapper otherPos)
+	{
+		return Math.abs(this.getX() - otherPos.getX()) + Math.abs(this.getY() - otherPos.getY()) + Math.abs(this.getZ() - otherPos.getZ());
+	}
 }