diff -r 96cb15a7611f -r 502c866b8512 src/linetypes/quadrilateral.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/linetypes/quadrilateral.h	Tue Feb 14 15:21:34 2017 +0200
@@ -0,0 +1,41 @@
+/*
+ *  LDForge: LDraw parts authoring CAD
+ *  Copyright (C) 2013 - 2017 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 "modelobject.h"
+
+/*
+ * Represents a single code-4 quadrilateral.
+ */
+class LDQuadrilateral : public LDObject
+{
+public:
+	static constexpr LDObjectType SubclassType = LDObjectType::Quadrilateral;
+
+	QString asText() const override;
+	void invert() override;
+	int numVertices() const override;
+	int triangleCount() const override;
+	LDObjectType type() const override;
+	QString typeName() const override;
+
+protected:
+	friend class Model;
+	LDQuadrilateral(Model* model);
+	LDQuadrilateral(const Vertex& v1, const Vertex& v2, const Vertex& v3, const Vertex& v4, Model* model = nullptr);
+};