[Development] QT_XCB_NATIVE_PAINTING makes worse that without of it

[Uwe Rathmann]

On 3/22/19 5:19 PM, Denis Shienkov wrote:

> My goal it is to accelerate my QWidget application in some way... I 
> use the QWT library to render a curves..

When setting QT_XCB_NATIVE_PAINTING ( Qt >= 5.10 ) you are usually
running into an hardware accelerated path, that is much faster, than
what you get from the raster paint engine. That's how it is on all
systems I'm running.

If this is not the case on your system I would expect, that there is
something wrong with your X11 setup.

So the first thing I would try is to do some tests on a Linux/X11
desktop system to be sure, that it is indeed an issue of the BSP on your
board.

> Is any suggestions to minimize the CPU load on iMX6 target (using 
> QWidget application)? Maybe is it possible to use an OpenGL at all 
> with X11?

OpenGL has a lower quality without being any faster, than the hardware
accelerated X11. And if your X11 setup on your board is not o.k. than
the OpenGL path is probably not better.

Uwe