如何使用一个形状或一组连接的形状在QPainter或QPainterPath中绘制自定义形状(像一个撕裂)

i have this simple question, i don't get to draw a shape like a tear but without using more that one shape (an ellipse and a polygon) because the QPen is draw for each shape, i want is something like join shapes for create a new one, or tell to QT that round the border across both shapes, for more information about what i want see the image, i want to create a shabe like that: i have this simple question, i don't get to dra