On Tue, 04 Sep 2018 14:38:47 +0300, Denis Shienkov wrote: > How I can do it for Qt4? Do you mean, I need to specify an appropriate > '-platform' option before starting of my application on Qt4?
https://doc.qt.io/archives/qt-4.8/qapplication.html#setGraphicsSystem You can even run opengl as backend for all widgets this way, what might be an option for non X11 platforms. I should pay more attention to this option for future Qwt releases. The vertical lines of the rubberbands are clipped away because of the 1 pixel left shift of the OpenGL paint engine, but the ticks of the axes and the grid lines of the canvas are correctly aligned - in opposite to the Qt5/QOpenGLWidget combination. But please allow me to repeat the hint about trying the QwtPlotCanvas::OpenGLBuffer option. It introduces some overhead, but at least avoids doing the rasterization of the vector data with the CPU. It works with Qt5 ( even with EGLFS ) without having to fiddle around with QOpenGLWidget. All you need to do is to add one line to your code: plot->canvas()->setPaintAttribute( QwtPlotCanvas::OpenGLBuffer ); Uwe PS: this starts to become too offtopic for this list _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development
