Why does QGraphicsView::update( const QRegion& ) cause the whole widget to be updated?

I have a large, complicated graphics view that takes a lot of processing to draw, and so I only want to redraw part of it (an OpenGL video display) ea ...

Change geometry of QRegion

I implemented autohide feature using QRegion and mouseMove event. Now I have another problem. I need to change geometry of QRegion during runtime but ...

QPaintEvent - updating only a region of the screen

in my code I'm trying to draw points every time my app gets GPS coordinates. The points are moved by "i" pixels to the right and down. I would like th ...