From c0908cf14fa194a56a3db6fb1801d2053c27746e Mon Sep 17 00:00:00 2001
From: Alexander Batalov <alex.batalov@gmail.com>
Date: Wed, 21 Dec 2022 09:18:29 +0300
Subject: [PATCH] Fix visual artifacts caused by null tiles

---
 src/map.cc | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/map.cc b/src/map.cc
index 0c3ad1b..79dc317 100644
--- a/src/map.cc
+++ b/src/map.cc
@@ -1716,6 +1716,18 @@ static int _square_load(File* stream, int flags)
         }
     }
 
+    // CE: Replace null tiles with a solid black tiles. This prevents copying
+    // buffer contents of nearby tiles during scrolling and repeating hex
+    // pointer when hovering mouse over null tiles.
+    for (int elevation = 0; elevation < ELEVATION_COUNT; elevation++) {
+        for (int tileIndex = 0; tileIndex < SQUARE_GRID_SIZE; tileIndex++) {
+            int tile = _square[elevation]->field_0[tileIndex];
+            if (tile == 0x00010001) {
+                _square[elevation]->field_0[tileIndex] = 0x00010293;
+            }
+        }
+    }
+
     return 0;
 }