https://bugs.kde.org/show_bug.cgi?id=453229
--- Comment #2 from Paul McAuley <k...@paulmcauley.com> --- I should also mention that the above 2 screenshots are at 250% scaling. I was looking into this more, and guessing this is probably because in Wayland scaled rendering is done relative to a smaller 100% scaled grid (e.g. at 250% scaling with a 2840x2160 display, rendering is done relative to 1536x864), so on Wayland you probably need to use floating point values for more precise shapes on screens with scaling > 100%. You can, however, only construct a QRegion using integers (QRect and QPolygon; not QRectF and QPolygonF). In my own window decoration ( https://github.com/paulmcauley/classik/commit/fe48c052f529e889706214c9af3db200fbfdb2a8#diff-1c44374ff8b2c6b8bea9596fe31ea4878a23bea2f62d2ce01dcbdf119dc98474R1319 ) I convert from a QPainterPath (in the shape of the window) to a QPolygonF to a QPolygon and finally to a QRegion. If my assumption about the cause of this problem is correct, I would then propose extending the setBlurRegion() API in the decoration to accept a QPainterPath or a QPolygonF. A QPolygonF can then be easily converted to a QPolygon (just converts qreal to int) and then to a QRegion at the last minute after scaling and directly before the effect is applied to the actual pixels on screen. -- You are receiving this mail because: You are watching all bug changes.
