From c376e695184ec53f3d0a7e0966aad1bfa2eee013 Mon Sep 17 00:00:00 2001
From: Perry Fraser <perryprog@users.noreply.github.com>
Date: Fri, 1 Aug 2025 17:48:40 -0400
Subject: [PATCH] Fix tabletop grids rarely spawning on top of another (#39327)

* fix: fix off-by-one for tabletop map positions

Ulam spirals start at 1, not 0.

* fix: make the ulam spiral a ulam spiral
---
 Content.Server/Tabletop/TabletopSystem.Map.cs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Content.Server/Tabletop/TabletopSystem.Map.cs b/Content.Server/Tabletop/TabletopSystem.Map.cs
index 5e116d81ef..89563ec6bf 100644
--- a/Content.Server/Tabletop/TabletopSystem.Map.cs
+++ b/Content.Server/Tabletop/TabletopSystem.Map.cs
@@ -37,7 +37,7 @@ namespace Content.Server.Tabletop
         /// <returns></returns>
         private Vector2 GetNextTabletopPosition()
         {
-            return UlamSpiral(_tabletops++) * TabletopSeparation;
+            return UlamSpiral(++_tabletops) * TabletopSeparation;
         }
 
         /// <summary>
@@ -62,11 +62,11 @@ namespace Content.Server.Tabletop
         /// <summary>
         ///     Algorithm for mapping scalars to 2D positions in the same pattern as an Ulam Spiral.
         /// </summary>
-        /// <param name="n">Scalar to map to a 2D position.</param>
+        /// <param name="n">Scalar to map to a 2D position. Must be greater than or equal to 1.</param>
         /// <returns>The mapped 2D position for the scalar.</returns>
         private Vector2i UlamSpiral(int n)
         {
-            var k = (int)MathF.Ceiling(MathF.Sqrt(n) - 1) / 2;
+            var k = (int)MathF.Ceiling((MathF.Sqrt(n) - 1) / 2);
             var t = 2 * k + 1;
             var m = (int)MathF.Pow(t, 2);
             t--;