diff -r cef43609a374 -r 0133e565e072 src/linetypes/object.h
--- a/src/linetypes/object.h	Sat Dec 14 23:00:01 2019 +0200
+++ b/src/linetypes/object.h	Wed Jan 01 17:45:56 2020 +0200
@@ -5,16 +5,24 @@
 #include "main.h"
 #include "colors.h"
 #include "vertex.h"
+#include "gl/common.h"
 
 namespace linetypes
 {
-	struct Id { unsigned int value; };
+	struct GetPolygonsContext;
 	enum class Property;
 	class Object;
 	class ColoredObject;
 	class Empty;
 }
 
+class DocumentManager;
+
+struct linetypes::GetPolygonsContext
+{
+	::DocumentManager* documents;
+};
+
 /**
  * @brief Different properties that can be queried with getProperty
  */
@@ -28,8 +36,7 @@
 	Point4, // Fourth vertex in a quadrilateral
 	ControlPoint1, // First control point in a conditional edge line
 	ControlPoint2, // Second control point in a conditional edge line
-	Position, // Position of a subfile reference
-	Transformation, // Transformation matrix of a subfile reference
+	Transformation, // 4x4 transformation matrix of a subfile reference
 	ReferenceName, // Subfile reference name
 	IsInverted, // Whether or not the object has been inverted with BFC INVERTNEXT
 	ErrorMessage // For error lines, why parsing failed
@@ -56,6 +63,7 @@
 	virtual QBrush textRepresentationForeground() const;
 	virtual QBrush textRepresentationBackground() const;
 	virtual QFont textRepresentationFont() const;
+	virtual void getPolygons(std::vector<gl::Polygon>& polygons, GetPolygonsContext* context) const;
 };
 
 class linetypes::ColoredObject : public Object
@@ -65,7 +73,7 @@
 	bool hasColor() const override final;
 	QVariant getProperty(Property id) const override;
 	SetPropertyResult setProperty(Property id, const QVariant& value) override;
-private:
+protected:
 	Color colorIndex = colors::main;
 };