diff -r 918b6c0f8b5b -r ed9685f44ab3 src/invert.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/invert.h	Sat Dec 14 22:36:06 2019 +0200
@@ -0,0 +1,27 @@
+/*
+ *  LDForge: LDraw parts authoring CAD
+ *  Copyright (C) 2013 - 2018 Teemu Piippo
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include "main.h"
+#include "matrix.h"
+#include "gl/common.h"
+
+bool isflat(class Model* model, Axis* axis);
+QMatrix4x4 flipmatrix(Axis dimension);
+//void invert(LDObject* obj, class DocumentManager* context);
+void invertPolygon(gl::Polygon& polygon);