From cc55ebb28fe32183d675d60ace27e81f69b7a910 Mon Sep 17 00:00:00 2001
From: Ottermandias <nickroederspam+git1@gmail.com>
Date: Thu, 29 Dec 2022 21:11:38 +0100
Subject: [PATCH] Add a suffix of a stable hash of the original filename to
 texture paths.

---
 Penumbra/Mods/ItemSwap/CustomizationSwap.cs |  1 +
 Penumbra/Mods/ItemSwap/ItemSwap.cs          | 22 +++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/Penumbra/Mods/ItemSwap/CustomizationSwap.cs b/Penumbra/Mods/ItemSwap/CustomizationSwap.cs
index 46b85f00..e442ae8e 100644
--- a/Penumbra/Mods/ItemSwap/CustomizationSwap.cs
+++ b/Penumbra/Mods/ItemSwap/CustomizationSwap.cs
@@ -144,6 +144,7 @@ public static class CustomizationSwap
 
         var newPath = ReplaceAnyRace( path, race );
         newPath = ReplaceAnyBody( newPath, slot, idFrom );
+        newPath = AddSuffix( newPath, ".tex", $"_{Path.GetFileName(texture.Path).GetStableHashCode():x8}", true );
         if( newPath != path )
         {
             texture.Path   = addedDashes ? newPath.Replace( "--", string.Empty ) : newPath;
diff --git a/Penumbra/Mods/ItemSwap/ItemSwap.cs b/Penumbra/Mods/ItemSwap/ItemSwap.cs
index 2e6585c3..3771cd6d 100644
--- a/Penumbra/Mods/ItemSwap/ItemSwap.cs
+++ b/Penumbra/Mods/ItemSwap/ItemSwap.cs
@@ -109,4 +109,26 @@ public static class ItemSwap
         file = null;
         return false;
     }
+
+    public static int GetStableHashCode( this string str )
+    {
+        unchecked
+        {
+            var hash1 = 5381;
+            var hash2 = hash1;
+
+            for( var i = 0; i < str.Length && str[ i ] != '\0'; i += 2 )
+            {
+                hash1 = ( ( hash1 << 5 ) + hash1 ) ^ str[ i ];
+                if( i == str.Length - 1 || str[ i + 1 ] == '\0' )
+                {
+                    break;
+                }
+
+                hash2 = ( ( hash2 << 5 ) + hash2 ) ^ str[ i + 1 ];
+            }
+
+            return hash1 + hash2 * 1566083941;
+        }
+    }
 }
\ No newline at end of file