diff -r cef43609a374 -r 0133e565e072 src/model.h
--- a/src/model.h	Sat Dec 14 23:00:01 2019 +0200
+++ b/src/model.h	Wed Jan 01 17:45:56 2020 +0200
@@ -4,6 +4,7 @@
 #include "main.h"
 #include "header.h"
 #include "linetypes/object.h"
+#include "gl/common.h"
 
 enum class HeaderProperty
 {
@@ -15,7 +16,7 @@
 	Q_OBJECT
 public:
 	class EditContext;
-	Model();
+	Model(QObject* parent = nullptr);
 	Model(const Model&) = delete;
 	int size() const;
 	EditContext edit();
@@ -24,6 +25,8 @@
 	QVariant getHeaderProperty(const HeaderProperty property);
 	const QString& getName() const;
 	QVariant getObjectProperty(const int index, const linetypes::Property property) const;
+	std::vector<gl::Polygon> getPolygons(class DocumentManager* documents) const;
+	void getObjectPolygons(const int index, std::vector<gl::Polygon>& polygons_out, linetypes::GetPolygonsContext* context) const;
 signals:
 	void objectAdded(linetypes::Id id, int position);
 private:
@@ -38,6 +41,8 @@
 	LDHeader header;
 	std::vector<ModelObjectPointer> body;
 	std::map<linetypes::Id, linetypes::Object*> objectsById;
+	mutable std::vector<gl::Polygon> cachedPolygons;
+	mutable bool needRecache = true;
 };
 
 template<typename T, typename... Args>