In opengl qt based application, I would like to create a custom 2d UI inside my viewport qopenglwidget.
I know that in qt3d and qtquick, it is triavial to add 2d UI with QML on the 3d scene.
My idea is the same by mixing qopenglwidget and qgraphicsciew as a child widget. Perhaps with qgraphicsitem, I will have total control of what will look my buttons, text etc.
So my question is, can I have a bad performance issue with such system?