diff -r 27fb1c3c9fbb -r 97b591813c8b src/polygoncache.h
--- a/src/polygoncache.h	Sun Mar 13 20:26:28 2022 +0200
+++ b/src/polygoncache.h	Tue Mar 15 18:52:48 2022 +0200
@@ -7,7 +7,7 @@
 	Q_OBJECT
 public:
 	PolygonCache(Model* model);
-	std::vector<gl::Polygon> getPolygons(class DocumentManager* documents);
+	const std::vector<gl::Polygon>& getPolygons(class DocumentManager* documents);
 private:
 	void getObjectPolygons(
 		const int index,