QGLWidget does strange drawings
i’d like to use OpenGL in a project. So, to get a starting point, i tried the 2DPainting example, playing a litte around. One of the first things i did, was switching antialiasing on and off, getting a strange effect. As you can see on the no-antialized picture, the circle-corners are some kind of, well, false-drawn.
When i turn on antialiasing, the circles don’t have those weird corners, but aren’t as round and smooth as in native mode.
So now, i’m not sure, if i still should use opengl. Sure, i could (and probably would) turn on antialiasing, but i wonder, why the quality is worse compared to the native mode… Or did anyone have a suggestion if i forgot something. I had the idea, that maybe double-buffering could solve the problem!?
Yes i do… Updated just a week ago to the newest driver available.
But good remark, i didn’t tell my system configuration. I’m working on Win7 Prof., with an Geforce 8800GTS. Maybe it could be a problem with nvidia-cards, because i tested the program on my notebook, with Win7, equipped with a nvidia 9650M GT, and had the same problem. But i think, other people would have reported the same issue.
you can run benchmark and check how your driver/gpu card is doing with this free s/w here [ozone3d.net]
I tested it on several pcs (unfortunately all equipped with nvidia cards, so i could not compare results on ati) – all produced the same output. I reported it to the Qt bug tracker.
For those who are interested: http://bugreports.qt.nokia.com/browse/QTBUG-16043
hm, i don’t think that this occures because of bad programming. I just used the 2D painting example that comes with Qt. I just added a few buttons to enable/disable antialiasing dynamically. Antialiasing is done by calling the QPainter::setRenderHint method with the arguments QPinter::Antialiasing and QPainter::HighQualityAntialiasing.