diff -r 40e2940605a3 -r 4bec0525ef1b src/linetypes/object.h
--- a/src/linetypes/object.h	Wed Mar 18 17:11:23 2020 +0200
+++ b/src/linetypes/object.h	Thu Mar 19 21:06:06 2020 +0200
@@ -30,12 +30,12 @@
 {
 	Color, // Color of the object
 	Text, // Text contained in a comment
-	Point1, // First vertex in a polygon or edge line
-	Point2, // Second vertex in a polygon or edge line
-	Point3, // Third vertex in a polygon
-	Point4, // Fourth vertex in a quadrilateral
-	ControlPoint1, // First control point in a conditional edge line
-	ControlPoint2, // Second control point in a conditional edge line
+	Point0, // First vertex in a polygon or edge line
+	Point1, // Second vertex in a polygon or edge line
+	Point2, // Third vertex in a polygon
+	Point3, // Fourth vertex in a quadrilateral
+	ControlPoint0, // First control point in a conditional edge line
+	ControlPoint1, // Second control point in a conditional edge line
 	Transformation, // 4x4 transformation matrix of a subfile reference
 	ReferenceName, // Subfile reference name
 	IsInverted, // Whether or not the object has been inverted with BFC INVERTNEXT
@@ -57,30 +57,49 @@
 
 	template<ldraw::Property property>
 	using PropertyType_t = typename PropertyType<property>::type;
+
+	struct PropertyKeyValue
+	{
+		Property key;
+		QVariant value;
+	};
+
+	constexpr Property pointProperty(int n)
+	{
+		Q_ASSERT(n >= 0 and n < 4);
+		return static_cast<Property>(static_cast<int>(Property::Point0) + n);
+	}
 }
 
 LDFORGE_DEFINE_PROPERTY_TYPE(Color, int)
 LDFORGE_DEFINE_PROPERTY_TYPE(Text, QString)
+LDFORGE_DEFINE_PROPERTY_TYPE(Point0, glm::vec3)
 LDFORGE_DEFINE_PROPERTY_TYPE(Point1, glm::vec3)
 LDFORGE_DEFINE_PROPERTY_TYPE(Point2, glm::vec3)
 LDFORGE_DEFINE_PROPERTY_TYPE(Point3, glm::vec3)
-LDFORGE_DEFINE_PROPERTY_TYPE(Point4, glm::vec3)
+LDFORGE_DEFINE_PROPERTY_TYPE(ControlPoint0, glm::vec3)
 LDFORGE_DEFINE_PROPERTY_TYPE(ControlPoint1, glm::vec3)
-LDFORGE_DEFINE_PROPERTY_TYPE(ControlPoint2, glm::vec3)
 LDFORGE_DEFINE_PROPERTY_TYPE(Transformation, glm::mat4)
 LDFORGE_DEFINE_PROPERTY_TYPE(ReferenceName, QString)
 LDFORGE_DEFINE_PROPERTY_TYPE(IsInverted, bool)
 LDFORGE_DEFINE_PROPERTY_TYPE(ErrorMessage, QString)
 
+#define LDRAW_OBJECT_HANDLE_SET_PROPERTY(PROPERTY, HANDLER) \
+	{this->handle<ldraw::Property::PROPERTY>(result, pair, \
+		[&](const ldraw::PropertyType_t<ldraw::Property::PROPERTY>& value) HANDLER);}
+
 class ldraw::Object
 {
 public:
 	enum class SetPropertyResult
 	{
 		Success = 0,
-		PropertyNotHandled,
-		InvalidValue
+		PropertyNotHandled
 	};
+	friend bool handled(SetPropertyResult result)
+	{
+		return result == SetPropertyResult::Success;
+	}
 	class BadPointIndex : public std::exception
 	{
 	};
@@ -88,10 +107,11 @@
 	Object(const Object&) = delete;
 	virtual ~Object();
 	const id_t id;
-	//virtual void toString(QTextStream &out) = 0;
 	virtual bool hasColor() const;
 	virtual QVariant getProperty(Property id) const;
-	virtual SetPropertyResult setProperty(Property id, const QVariant& value);
+	template<ldraw::Property property>
+	SetPropertyResult setProperty(const PropertyType_t<property>& value);
+	SetPropertyResult setProperty(const PropertyKeyValue& pair);
 	virtual QString textRepresentation() const = 0;
 	virtual QBrush textRepresentationForeground() const;
 	virtual QBrush textRepresentationBackground() const;
@@ -100,16 +120,39 @@
 	virtual void invert() {}
 	virtual int numPoints() const { return 0; }
 	virtual const glm::vec3& getPoint(int index) const;
+protected:
+	template<Property property, typename Function>
+	void handle(SetPropertyResult* result, const PropertyKeyValue& pair, Function function);
+	virtual void setProperty(SetPropertyResult* result, const PropertyKeyValue& pair);
 };
 
+template<ldraw::Property property>
+ldraw::Object::SetPropertyResult ldraw::Object::setProperty(const PropertyType_t<property>& value)
+{
+	SetPropertyResult result = SetPropertyResult::PropertyNotHandled;
+	this->setProperty(&result, PropertyKeyValue{property, QVariant::fromValue(value)});
+	return result;
+}
+
+template<ldraw::Property property, typename Function>
+void ldraw::Object::handle(SetPropertyResult* result, const PropertyKeyValue& pair, Function function)
+{
+	if (pair.key == property)
+	{
+		function(pair.value.value<ldraw::PropertyType_t<property>>());
+		*result = SetPropertyResult::Success;
+	}
+}
+
 class ldraw::ColoredObject : public Object
 {
 public:
 	ColoredObject(const Color colorIndex = ldraw::mainColor);
 	bool hasColor() const override final;
 	QVariant getProperty(Property id) const override;
-	SetPropertyResult setProperty(Property id, const QVariant& value) override;
 	Color colorIndex = ldraw::mainColor;
+protected:
+	void setProperty(SetPropertyResult* result, const PropertyKeyValue& pair) override;
 };
 
 /**