Hi,
I discovered that it does not behave always like that. It happens only
when painting very quickly many small QImages with transparent areas.
And I found a way to fix it, but this is just adding mystery.
Instead of
pnt->drawImage(etc);
I do
pnt.beginNativePainting();
pnt.endNativePainting();
pnt->drawImage(etc);
This seems to force a kind of flush and all is fine after that.
Should I report a bug?
Thanks
Philippe
Le 01-05-2022 13:45, maitai a écrit :
Hi,
I have some heavy rendering that I would like to speed up using openGL.
For the time being using only QPainter regular method but later some
native openGL code.
So instead of painting on a QImage, I am painting on a
QOpenGLPaintDevice. All is fine except one point: When the painter
draws a QImage containing alpha, these alpha pixels appear black.
CompositionMode is QPainter::CompositionMode_SourceOver and QImage
format for the source is QImage::Format_ARGB32_Premultiplied. Same code
painting in a QImage works fine.
I have tried to glEnable(GL_BLEND) and glEnable(GL_DEPTH_TEST) and some
others but that didn't fix the issue.
Any idea of what needs to be done ?
Many thanks in advance
Philippe Lelong
_______________________________________________
Interest mailing list
Interest@qt-project.org
https://lists.qt-project.org/listinfo/interest
_______________________________________________
Interest mailing list
Interest@qt-project.org
https://lists.qt-project.org/listinfo/interest
