From 74228a2851d64f3f3ad472607a570b28af48da26 Mon Sep 17 00:00:00 2001
From: Jarrod Doyle <thejarroddoyle@gmail.com>
Date: Sat, 4 Jan 2025 21:03:57 +0000
Subject: [PATCH] Fix incorrect loop back logic in recursive section

---
 KeepersCompound.Lightmapper/PotentiallyVisibleSet.cs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/KeepersCompound.Lightmapper/PotentiallyVisibleSet.cs b/KeepersCompound.Lightmapper/PotentiallyVisibleSet.cs
index 5f18eef..96b49ca 100644
--- a/KeepersCompound.Lightmapper/PotentiallyVisibleSet.cs
+++ b/KeepersCompound.Lightmapper/PotentiallyVisibleSet.cs
@@ -179,18 +179,19 @@ public class PotentiallyVisibleSet
         foreach (var edgeIndex in _portalGraph[currentCellIdx])
         {
             var edge = _edges[edgeIndex];
-            var destination = edge.Left == previousCellIdx ? edge.Right : edge.Left;
-            if (destination == previousCellIdx || previousPoly.IsCoplanar(edge.Poly))
+            var loopsBack = edge.Left == previousCellIdx || edge.Right == previousCellIdx;
+            if (loopsBack || previousPoly.IsCoplanar(edge.Poly))
             {
                 continue;
             }
-
+            
             var poly = separators.Aggregate(edge.Poly, ClipPolygonByPlane);
             if (poly.Vertices.Length == 0)
             {
                 continue;
             }
             
+            var destination = edge.Left == currentCellIdx ? edge.Right : edge.Left;
             ComputeClippedVisibility(visible, sourcePoly, poly, currentCellIdx, destination, depth + 1);
         }
     }