diff --git a/src/tarray.h b/src/tarray.h
index 524c0942e8..1c5faca437 100644
--- a/src/tarray.h
+++ b/src/tarray.h
@@ -497,6 +497,14 @@ public:
 			Array = nullptr;
 		}
 	}
+
+	void Swap(TArray<T, TT> &other)
+	{
+		std::swap(Array, other.Array);
+		std::swap(Count, other.Count);
+		std::swap(Most, other.Most);
+	}
+
 private:
 	T *Array;
 	unsigned int Count;
@@ -760,6 +768,7 @@ struct FMap
 	hash_t NumUsed;
 };
 
+
 template<class KT, class VT, class MapType> class TMapIterator;
 template<class KT, class VT, class MapType> class TMapConstIterator;
 
@@ -947,6 +956,14 @@ public:
 		DelKey(key);
 	}
 
+	void Swap(MyType &other)
+	{
+		std::swap(Nodes, other.Nodes);
+		std::swap(LastFree, other.LastFree);
+		std::swap(Size, other.Size);
+		std::swap(NumUsed, other.NumUsed);
+	}
+
 protected:
 	struct IPair	// This must be the same as Pair above, but with a
 	{				// non-const Key.
@@ -1518,4 +1535,3 @@ private:
 	T *Array;
 	unsigned int Count;
 };
-
diff --git a/src/textures/formats/multipatchtexture.h b/src/textures/formats/multipatchtexture.h
index 3d78008328..8337ffe6c1 100644
--- a/src/textures/formats/multipatchtexture.h
+++ b/src/textures/formats/multipatchtexture.h
@@ -89,8 +89,30 @@ struct BuildInfo
 	int LeftOffset[2] = {};
 	int TopOffset[2] = {};
 	FImageTexture *tex = nullptr;
+
+	void swap(BuildInfo &other)
+	{
+		Name.Swap(other.Name);
+		Parts.Swap(other.Parts);
+		Inits.Swap(other.Inits);
+		std::swap(Width, other.Width);
+		std::swap(Height, other.Height);
+		std::swap(Scale, other.Scale);
+		std::swap(bWorldPanning, other.bWorldPanning);
+		std::swap(DefinitionLump, other.DefinitionLump);
+		std::swap(bComplex, bComplex);
+		std::swap(textual, other.textual);
+		std::swap(bNoDecals, other.bNoDecals);
+		std::swap(LeftOffset[0], other.LeftOffset[0]);
+		std::swap(LeftOffset[1], other.LeftOffset[1]);
+		std::swap(TopOffset[0], other.TopOffset[0]);
+		std::swap(TopOffset[1], other.TopOffset[1]);
+		std::swap(tex, other.tex);
+	}
 };
 
+
+
 class FMultipatchTextureBuilder
 {
 	FTextureManager &TexMan;
diff --git a/src/textures/multipatchtexturebuilder.cpp b/src/textures/multipatchtexturebuilder.cpp
index 7be8a69e53..4675220f55 100644
--- a/src/textures/multipatchtexturebuilder.cpp
+++ b/src/textures/multipatchtexturebuilder.cpp
@@ -922,11 +922,21 @@ void FMultipatchTextureBuilder::ResolveAllPatches()
 	}
 	// Now try to resolve the images. We only can do this at the end when all multipatch textures are set up.
 	int i = 0;
+
+	// reverse the list so that the Delete operation in the loop below deletes at the end.
+	// For normal sized lists this is of no real concern, but Total Chaos has over 250000 textures where this becomes a performance issue.
+	for (unsigned i = 0; i < BuiltTextures.Size() / 2; i++)
+	{
+		// std::swap is VERY inefficient here...
+		BuiltTextures[i].swap(BuiltTextures[BuiltTextures.Size() - 1 - i]);
+	}
+
+
 	while (BuiltTextures.Size() > 0)
 	{
 		bool donesomething = false;
 
-		for (unsigned i = 0; i < BuiltTextures.Size(); i++)
+		for (int i = BuiltTextures.Size()-1; i>= 0; i--)
 		{
 			auto &buildinfo = BuiltTextures[i];
 			bool hasEmpty = false;
@@ -969,7 +979,6 @@ void FMultipatchTextureBuilder::ResolveAllPatches()
 				}
 
 				BuiltTextures.Delete(i);
-				i--;
 				donesomething = true;
 			}
 		}
diff --git a/src/zstring.h b/src/zstring.h
index 67fef4a181..334fbcb1f1 100644
--- a/src/zstring.h
+++ b/src/zstring.h
@@ -148,6 +148,11 @@ public:
 	char *LockBuffer();		// Obtain write access to the character buffer
 	void UnlockBuffer();	// Allow shared access to the character buffer
 
+	void Swap(FString &other)
+	{
+		std::swap(Chars, other.Chars);
+	}
+
 	operator const char *() const { return Chars; }
 
 	const char *GetChars() const { return Chars; }