Hi there, On my Linux computer (KUbuntu 16.10, AMD CPU), I'm having a big performance problem with a very simple scene containing a single ellipse with a drop shadow effect. When zooming in, the CPU usage goes to 100% and the view takes ages to draw. This is very simple to reproduce, no need for a complex scene: m_scene = new QGraphicsScene(this); auto item = m_graphicsScene->addEllipse(-10, -10, 20, 20); item->setGraphicsEffect(new QGraphicsDropShadowEffect()); m_view->setScene(m_scene);
If i remove the drop shadow effect, everything runs fine. I have tried this at work on a Windows computer with Intel CPU and i don't have this problem. I have run valgrind function profiler here, and it seems that my app spend most of it's time in: - QApplication::exec()/QGuiApplication::exec() - _dl_runtime_resolv_avx/_dl_runtime_resolve_avx'2 Tested on KUbuntu with Qt 5.6.1 (as shipped by the distro), Qt 5.7 (online installer), i have the same problem. Uing QtCreator i have tried to rebuild the app with a clean build environment and ran it with a clean run environment, it didn't make any difference. Tested on Windows with Qt 5.7 (online installer), i don't have any problem. Has anyone seen this sort of behaviour, any clue on how to investigate further and fix this? Thanks, Chris _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
