I'm using QOpenGLWidget widget in a QGraphicsView/Scene, this widget should be able to display images that can be huge, in QOpenGLWidget this slows down the application immensely since the OpenGL window is at the size of the widget which is at the size of the huge image even though the visible displayed window is always small, equal or less than the size of the screen.
In other words, is there a way to make the widget rendering resolution the same size as the "physical" widget size on screen instead of always rendering at the potentially huge image size?
PS: I know I can scale the widget myself, but this will force me to change the size and location of every other widget in the QGraphicsView, I'd like to avoid this if possible. Grabbing the frambuffer to a QImage then scaling that up might be an option, but it is also somewhat slow, I'd like to avoid that too if possible.