diff -r 27fb1c3c9fbb -r 97b591813c8b src/ldrawalgorithm.cpp
--- a/src/ldrawalgorithm.cpp	Sun Mar 13 20:26:28 2022 +0200
+++ b/src/ldrawalgorithm.cpp	Tue Mar 15 18:52:48 2022 +0200
@@ -2,10 +2,10 @@
 #include "linetypes/quadrilateral.h"
 #include "linetypes/triangle.h"
 
-void ldraw::invert(ModelEditor& editor, ldraw::id_t id)
+void ldraw::invert(ModelEditor& editor, ldraw::id_t id, GetPolygonsContext* context)
 {
-	editor.modifyObject(id, [](ldraw::Object* object){
-		object->invert();
+	editor.modifyObject(id, [context](ldraw::Object* object){
+		object->invert(context);
 	});
 }