diff -r 35bbfad4d0f4 -r a38a0eb007b0 src/tools/drawtool.h
--- a/src/tools/drawtool.h	Tue Mar 15 18:56:02 2022 +0200
+++ b/src/tools/drawtool.h	Tue Mar 15 19:48:07 2022 +0200
@@ -1,7 +1,30 @@
 #pragma once
 #include "basetool.h"
 
-class DrawTool : public BaseTool
+class AbstractDrawTool : public BaseTool
+{
+public:
+	AbstractDrawTool(Document* document);
+	void reset() override;
+	void overpaint(Canvas*, QPainter*) const override;
+	bool mouseMove(Document* document, Canvas* canvas, QMouseEvent* event) override;
+	bool mouseClick(Canvas* canvas, QMouseEvent* event) override;
+	bool keyReleased(Document*, Canvas* canvas, QKeyEvent* event) override;
+protected:
+	void addCurrentPoint(Canvas *canvas);
+	virtual void addPoint(const glm::vec3& pos);
+	virtual void closeShape() = 0;
+	void removeLastPoint();
+	void clearPoints();
+	bool isCloseToExistingPoints(const glm::vec3& pos) const;
+	std::vector<glm::vec3> polygon;
+	std::vector<glm::vec3> previewPolygon;
+	glm::vec3 previewPoint;
+	bool isconcave = false;
+	void updatePreviewPolygon();
+};
+
+class DrawTool : public AbstractDrawTool
 {
 	Q_OBJECT
 
@@ -10,17 +33,8 @@
 
 	QString name() const override;
 	QString toolTip() const override;
-	bool mouseClick(Document* document, Canvas* canvas, QMouseEvent* event) override;
-	bool mouseMove(Document* document, Canvas* canvas, QMouseEvent* event) override;
-	bool keyReleased(Document*, Canvas* canvas, QKeyEvent* event) override;
-	void reset() override;
-	void overpaint(Canvas*, QPainter*) const override;
 	QString iconName() const override;
-private:
-	void closeShape(Document *document);
-	std::vector<glm::vec3> polygon;
-	std::vector<glm::vec3> previewPolygon;
-	glm::vec3 previewPoint;
-	bool isconcave = false;
-	void updatePreviewPolygon();
+protected:
+	virtual void addPoint(const glm::vec3& pos) override;
+	void closeShape() override;
 };