Hi all,
I have an idea how to avoid flickering, but I don't know about results:
what if I will discard the Open GL support in favor to Quick2 render?
I have read this documentation: http://doc.qt.io/QtQuick2DRenderer/
which says about the "Qt Quick 2D Renderer" module.
So, my things is:
1. Download && build && install this module:
git://code.qt.io/qt/qtdeclarative-render2d.git
2. Use this env variable:
export QMLSCENE_DEVICE=softwarecontext
3. Run my app...
But, I don't understand:
1) What of engine is used to 2D rendering in case if I have EGLFS only?
2) Should I re-build Qt5 too with the "--no-opengl" option (or I can
keep the "-opengl es2" option) ?
04.08.2016 16:10, Denis Shienkov пишет:
Hi Robin,
> Repeating my last answer...
> http://lists.qt-project.org/pipermail/development/2016-July/026736.html
I'm sorry, but I did not receive (did not see) your last answer.
> I'm going to guess you're using eglfs or something like that
Yes, I use EGLFS via X11 on Linux Apalis T30 board, where are used
NVIDIA's drivers.
Seems, the flickering is when are used:
export QT_QPA_EGLFS_FORCE888=1
ENV variable... (I need this variable to smooth the Image's
gradients... even X11 started with 24-bit depth).
PS: But, I'm not sure about QT_QPA_EGLFS_FORCE888... :(
> Using an overlay to debug item positions (QSG_VISUALIZE=overdraw)
could be handy for trying to rule
this out, as if it is specific to the application,
Ok, many thanks, I will try it.
2016-08-04 14:57 GMT+03:00 Robin Burchell <robin...@viroteck.net
<mailto:robin...@viroteck.net>>:
Repeating my last answer...
http://lists.qt-project.org/pipermail/development/2016-July/026736.html
On Thu, Aug 4, 2016, at 01:50 PM, Denis Shienkov wrote:
> {quote}
>
> Hi all.
>
> I have some QML application, where just use QQuickView as QML
container.
> This application uses Qt 5.7.x and running on Linux embedded
board with
> the
> NVIDIA core (Toradex Apalis T30).
>
> But sometimes I got flickering in process of animation. A flickering
> represents in form of a "white" strips with full-screen width
and 1/5-1/6
> screen heigth. This flickers happens quickly and frequently
(every ~20-60
> seconds, randomly)...
>
> I have seen this "Avoiding graphics flicker in Qt / QML" [1]
blog where
> are
> used QML with Qt 4.x,
> where were used this trics:
>
> {code}
> int main(int argc, char **argv)
> {
> ...
> view.setAttribute(Qt::WA_OpaquePaintEvent);
> view.setAttribute(Qt::WA_NoSystemBackground);
> view.viewport()->setAttribute(Qt::WA_OpaquePaintEvent);
> view.viewport()->setAttribute(Qt::WA_NoSystemBackground);
> ...
> }
> {code}
>
> But, in my case I have use Quick v2, with QQuickView instead of
> QDeclarativeView,
> which does not allowed to setup any attributes.
>
> So, my questions is: is there are any way to setup
> Qt::WA_OpaquePaintEvent
> and/or
> Qt::WA_NoSystemBackground in Quck2? Or, maybe is it possible to use
> another
> tricks?
>
> BR,
> Denis
>
>
[1]https://blog.rburchell.com/2011/11/avoiding-graphics-flicker-in-qt-qml.html
>
> {quote}
>
> This flickering present on some HDMI displays...
>
> We currently have this flags:
>
> {code}
> ...
> view.setFlags(Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint);
> ...
> {code}
>
> Maybe is it an reasons of flikering? Has someone any ideas?
>
> BR,
> Denis
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