From 52608a9f3f737389b1ea724ed360d27c1945e8fc Mon Sep 17 00:00:00 2001
From: James Seibel <jeseibel@gondtc.com>
Date: Sun, 8 Aug 2021 22:06:45 -0500
Subject: [PATCH] Create issue #54

---
 .../lod/objects/LodQuadTreeDimension.java     |  8 +++----
 .../java/com/seibel/lod/util/LodUtil.java     | 24 +++++--------------
 2 files changed, 10 insertions(+), 22 deletions(-)

diff --git a/src/main/java/com/seibel/lod/objects/LodQuadTreeDimension.java b/src/main/java/com/seibel/lod/objects/LodQuadTreeDimension.java
index cba728b30..b07f79571 100644
--- a/src/main/java/com/seibel/lod/objects/LodQuadTreeDimension.java
+++ b/src/main/java/com/seibel/lod/objects/LodQuadTreeDimension.java
@@ -385,10 +385,10 @@ public class LodQuadTreeDimension
 		if (detailLevel > LodQuadTreeNode.REGION_LEVEL)
 			throw new IllegalArgumentException("getLodFromCoordinates given a level of \"" + detailLevel + "\" when \"" + LodQuadTreeNode.REGION_LEVEL + "\" is the max.");
 		
-		// TODO possibly put this in LodUtil
-		int regionPosX = Math.floorDiv(chunkPos.x, (int) Math.pow(2,LodQuadTreeNode.REGION_LEVEL - detailLevel));
-        int regionPosZ = Math.floorDiv(chunkPos.z, (int) Math.pow(2,LodQuadTreeNode.REGION_LEVEL - detailLevel));
-    	LodQuadTree region = getRegion(new RegionPos(regionPosX, regionPosZ));
+		// issue #54
+		// TODO this works, but only in all positive coordinates.
+		int[] relativePos = LodUtil.convertAbsolutePosToQuadTreeRelativePos(chunkPos.x, chunkPos.z, LodQuadTreeNode.CHUNK_LEVEL);
+    	LodQuadTree region = getRegion(new RegionPos(relativePos[0], relativePos[1]));
 		
 		if(region == null)
 		{
diff --git a/src/main/java/com/seibel/lod/util/LodUtil.java b/src/main/java/com/seibel/lod/util/LodUtil.java
index 49dabae19..dfabb4b4d 100644
--- a/src/main/java/com/seibel/lod/util/LodUtil.java
+++ b/src/main/java/com/seibel/lod/util/LodUtil.java
@@ -20,12 +20,11 @@ package com.seibel.lod.util;
 import java.awt.Color;
 import java.io.File;
 
-import com.seibel.lod.objects.RegionPos;
+import com.seibel.lod.objects.LodQuadTreeNode;
 
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.multiplayer.ServerData;
 import net.minecraft.server.integrated.IntegratedServer;
-import net.minecraft.util.math.ChunkPos;
 import net.minecraft.world.DimensionType;
 import net.minecraft.world.IWorld;
 import net.minecraft.world.chunk.ChunkSection;
@@ -96,25 +95,14 @@ public class LodUtil
 	}
 	
 	/**
-	 * Convert the given ChunkPos into a RegionPos.
+	 * Convert a 2D absolute position into a quad tree relative position. 
 	 */
-	public static RegionPos convertChunkPosToRegionPos(ChunkPos pos)
+	public static int[] convertAbsolutePosToQuadTreeRelativePos(int x, int z, int detailLevel)
 	{
-		RegionPos rPos = new RegionPos();
-		rPos.x = pos.x / 512;
-		rPos.z = pos.z / 512;
+		int relativePosX = Math.floorDiv(x, (int) Math.pow(2, LodQuadTreeNode.REGION_LEVEL - detailLevel));
+		int relativePosZ = Math.floorDiv(z, (int) Math.pow(2, LodQuadTreeNode.REGION_LEVEL - detailLevel));
 		
-		// prevent issues if X/Z is negative and less than 16
-		if (pos.x < 0)
-		{
-			rPos.x = (Math.abs(rPos.x) * -1) - 1; 
-		}
-		if (pos.z < 0)
-		{
-			rPos.z = (Math.abs(rPos.z) * -1) - 1; 
-		}
-		
-		return rPos;
+		return new int[] {relativePosX, relativePosZ};
 	}
 	
 	/**