From a985e1c54239283296107daff8ec41a2ecaa7a49 Mon Sep 17 00:00:00 2001
From: James Seibel <jeseibel@gondtc.com>
Date: Sat, 25 Mar 2023 07:43:55 -0500
Subject: [PATCH] Fix quadNode getChildByIndex inconsistent with DhSectionPos

---
 .../core/util/objects/quadTree/QuadNode.java  | 12 +++++------
 core/src/test/java/tests/QuadTreeTest.java    | 20 +++++++++++++++++++
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/core/src/main/java/com/seibel/lod/core/util/objects/quadTree/QuadNode.java b/core/src/main/java/com/seibel/lod/core/util/objects/quadTree/QuadNode.java
index a37287650..434340e65 100644
--- a/core/src/main/java/com/seibel/lod/core/util/objects/quadTree/QuadNode.java
+++ b/core/src/main/java/com/seibel/lod/core/util/objects/quadTree/QuadNode.java
@@ -74,10 +74,10 @@ public class QuadNode<T>
 	 * Returns the DhLodPos 1 detail level lower <br><br>
 	 *
 	 * Relative child positions returned for each index: <br>
-	 * 0 = (0,0) <br>
-	 * 1 = (1,0) <br>
-	 * 2 = (0,1) <br>
-	 * 3 = (1,1) <br>
+	 * 0 = (0,0) - North West <br>
+	 * 1 = (1,0) - South West <br>
+	 * 2 = (0,1) - North East <br>
+	 * 3 = (1,1) - South East <br>
 	 *
 	 * @param child0to3 must be an int between 0 and 3
 	 */
@@ -88,9 +88,9 @@ public class QuadNode<T>
 			case 0:
 				return nwChild;
 			case 1:
-				return neChild;
-			case 2:
 				return swChild;
+			case 2:
+				return neChild;
 			case 3:
 				return seChild;
 			
diff --git a/core/src/test/java/tests/QuadTreeTest.java b/core/src/test/java/tests/QuadTreeTest.java
index 101866228..4feff37f0 100644
--- a/core/src/test/java/tests/QuadTreeTest.java
+++ b/core/src/test/java/tests/QuadTreeTest.java
@@ -523,6 +523,26 @@ public class QuadTreeTest
 		}
 	}
 	
+	@Test
+	public void quadNodeChildPositionIndexTest()
+	{
+		QuadNode<Integer> rootNode = new QuadNode<>(new DhSectionPos((byte)10, 0, 0), (byte)0);
+		rootNode.forEachDirectChild((child, childPos) ->
+		{
+			rootNode.setValue(childPos, 1, null);
+		});
+		Assert.assertEquals("node not filled", rootNode.getChildValueCount(), 4);
+		
+		
+		for (int i = 0; i < 4; i++)
+		{
+			DhSectionPos childPos = rootNode.sectionPos.getChildByIndex(i);
+			QuadNode<Integer> childNode = rootNode.getChildByIndex(i);
+			Assert.assertEquals("child position not the same as "+DhSectionPos.class.getSimpleName()+"'s getChildByIndex()", childPos, childNode.sectionPos);
+		}
+		
+	}
+