From 875dcbb92650c93f9d2991630a132fe41852fe8c Mon Sep 17 00:00:00 2001
From: haunter <haunter@noreply.localhost>
Date: Sun, 17 Aug 2025 20:23:14 +0000
Subject: [PATCH] Update town.js

---
 town.js | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/town.js b/town.js
index fb81c5a..a5c5982 100644
--- a/town.js
+++ b/town.js
@@ -54,9 +54,10 @@
     // Compute Sea from x,y
     // -----------------------------
     function computeSea(x, y) {
-        const seaY = Math.floor(y / 100);
-        const seaX = Math.floor(x / 100);
-        return seaY * 10 + seaX;
+        if (typeof x !== 'number' || typeof y !== 'number') return null;
+        const sx = Math.floor(x / 100); // col (0-based)
+        const sy = Math.floor(y / 100); // row (0-based)
+        return sx * 10 + sy;
     }
 
     // -----------------------------