[Interest] Poor retina support for QGraphicsView on macOS?

Jean-Michaël Celerier jeanmichael.celerier at gmail.com
Sat Oct 7 19:01:13 CEST 2017


> Don't do that and the anti-aliasing will work.

Or alternatively enable GL antialiasing for instance by using
QSurfaceFormat::setSamples (
http://doc.qt.io/qt-5/qsurfaceformat.html#setSamples) and passing the
format to your GL viewport. However this ends up being quite slow on retina
display in my experience.



-------
Jean-Michaël Celerier
http://www.jcelerier.name

On Sat, Oct 7, 2017 at 10:09 AM, Christian Gagneraud <chgans at gmail.com>
wrote:

> On 7 October 2017 at 16:11, Patrick Stinson <patrickkidd at gmail.com> wrote:
> >
> > Hello!
> >
> > I am seeing the antialiasing is still quite grainy using a QGraphicsView
> on mac. Is it possible to increase the device pixel ratio, or something
> similar?
> >
> > See attached screenshots, expanding to full rez before viewing. Note
> smoothness of retina button pixmaps at left VS jagged lines in middle.
> >
> > I am using a QOpenGLWidget for the viewport (though this doesn’t seem to
> matter):
>
> I vaguely remember that anti-aliasing doesn't work with an OpenGL view
> (that was on a Linux machine).
>
> > view.setViewport(QOpenGLWidget())
>
> Don't do that and the anti-aliasing will work.
>
> Chris
>
>
>
> >
> > I am painting QPainterPaths like this:
> >
> > def paint(self, painter, option, widget):
> >     painter.save()
> >     painter.setPen(self.pen)
> >     painter.setBrush(self.brush)
> >     painter.drawPath(self.path)
> >     painter.restore()
> >
> > with the following render hints:
> >
> > view.setRenderHints(QPainter.Antialiasing|QPainter.
> HighQualityAntialiasing|QPainter.SmoothPixmapTransform|
> QPainter.TextAntialiasing)
> >
> > and the following attribute set on the QApplication:
> >
> > app.setAttribute(Qt.AA_UseHighDpiPixmaps, True)
> >
> > Thanks!
> > -P
> >
> >
> >
> >
> >
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> > Interest at qt-project.org
> > http://lists.qt-project.org/mailman/listinfo/interest
> >
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