[Development] Does iMX6 support EGL on X11 feature?

Uwe Rathmann Uwe.Rathmann at tigertal.de
Sun Mar 24 13:15:59 CET 2019


On 3/22/19 8:28 PM, Konstantin Tokarev wrote:

> BTW, if your main concern is the performance of real-time plotting,
> it's extremely unlikely that you'll get better results on EGL/X11
> than on EGLFS or EGL/Wayland. Note that you can use QWidgets on any
> of these platforms without restrctions.

Not being able to run the X11 paint engine is the restriction. Using the
OpenGL paint engine is a replacement in terms of performance, but it
does not have the same quality.

Using the OpenGL paint engine as backend in general was possible with 
Qt4, but with Qt5 only widgets being derived from QOpenGLWidget can do 
this - what excludes all standard widgets you find in Qt.

What hurts most about the OpenGL paint engine in the context of Qwt is
that it has an offset of 1 pixel compared to what the raster paint
engine does. Also the result between X11 and Raster differs, what is a 
major pain, when you need to be pixel perfect.

It is unfortunate, that a toolkit that has "cross platform" as major
selling point has these type of incompatibilities, but this is how it is.

Uwe






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