On Wed, 29 Aug 2018 16:43:40 +0300, Denis Shienkov wrote: > So, there are no way to improve an acceleration and to minimize the CPU > loading?
It depends on the requirements of your application, but when it comes to oscilloscope alike widgets your best choice is Qt4/X11. The X11 paint engine is hardware accelerated, it even allows painting outside of paint events - what is important for incremental painting. ( The fact, that Qt 4.8 prefers using raster with the argument of performance it is totally nonsense, when it comes to any sort of vector graphics. ) Furthermore the X11 paint engine simply has a better quality. The sort of bugs coming and going with the various Qt versions is a nightmare for any sort of graphics framework. Actually my job for today is to find a work around for this one: https://bugreports.qt.io/browse/QTBUG-70101 -- If you need to go with Qt5 I would recommend to use a platform that allows for using QOpenGlWidget - X11 again is IMHO not a bad choice. Actually one of our terminals is a iMX6, where we do this ( because we needed VNC support ). Next I recommend Qwt from SVN trunk, where you can simply assign a QwtPlotOpenGLCanvas to achieve hardware acceleration. The quality of the OpenGL paint engine is not as good as X11 or Raster, but for a oscilloscope things usually do not need to be pixel perfect. -- Finally you should not ignore algorithmic options to reduce what has to be painted. How to optimize the rendering process is often quite individual, but often QwtPlotCurve::FilterPointsAggressive ( since Qwt 6.2 ) has a significant effect in oscilloscope alike applications. In fact I have been contacted quite often with oscilloscope applications struggling with performance issues and often it could be solved on a algorithmic level. As an inspiration you could also try to run the oscilloscope demo of Qwt on your board. You will notice, that it runs with almost no CPU usage because it mostly paints incrementally. Of course this only works because the design of the user interface is made for this, but maybe you can do something similar. Uwe _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development