[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 --- Comment #11 from Sven Brauch --- FWIW I would provide a patch for this if I could, but I think it's not possible right now. Gwenview wants to 1:1 map image pixels to screen pixels for zoom = 100%. It cannot do that if it gets a surface from the compositor intended for some scale factor, but no correct information about what that scale factor actually is. -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 Nate Graham changed: What|Removed |Added Keywords||wayland -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 Nate Graham changed: What|Removed |Added CC||slartibar...@gmail.com --- Comment #10 from Nate Graham --- *** Bug 466738 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 Nate Graham changed: What|Removed |Added Status|REPORTED|CONFIRMED Ever confirmed|0 |1 -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 --- Comment #9 from Sven Brauch --- Hi, I tried this and I think Jorge did too, and both of us get "2.0" from QApplication::devicePixelRatio() with 125% scaling configured in systemsettings. I also tried in Qt6, and I *still* get "2.0". Gwenview as a whole scales fine, but the QGraphicsView code calculating the image size for 100% zoom does not. It ends up with a result that doesn't fill the screen, even though the image has as many pixels as the screen has, because devicePixelRatio() is wrong (or is the "2" correct? I think not). Launching with "-platform xcb" (on Wayland) makes QApplication::devicePixelRatio() return 1.25 as expected, and also makes Gwenview's image scaling work correctly again. I'm running plasmashell 5.26.5 on Manjaro. -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 --- Comment #8 from Nate Graham --- Wayland does support fractional scaling, it's just that the result is a bit blurry in Qt 5. In 6, this is better. That shouldn't affect Gwenview though and using devicePixelRatioF() is sane. Feel free to submit a patch! -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 --- Comment #7 from Sven Brauch --- To clarify again, I think there is no problem in Gwenview, its code already accounts for display scaling in abstractimageview.cpp. It just gets the wrong scale from Qt. -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 Sven Brauch changed: What|Removed |Added CC||n...@kde.org -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 --- Comment #6 from Sven Brauch --- Ok, the situation here seems to be that Wayland only supports integer scaling at the moment. My 125% scaling is rounded up to 2, which is what is used by Gwenview to scale the image, which makes it 2 / 1.25 = 1.6 times = 160% too small. Apparently Nate knows about this situation? I will add him to the CC list of this bug. :) But as I understood, there is nothing that can be done right now until either Qt6 or until support for fractional scaling on Wayland (which does exist) is backported to Qt5. -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 --- Comment #5 from Sven Brauch --- You need devicePixelRatioF for sure, devicePixelRatio is only for integer scaling. -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 --- Comment #4 from Jorge --- Using "devicePixelRatio" methods returns "2" in my case, which may be due to using KF5/Qt5 under Wayland. I've tried building with Qt6 but with no luck :-/ -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 --- Comment #3 from Sven Brauch --- By the way, on my screen on Wayland, 125% wouldn't fit either. I need to set ~160%, which I can't make sense of. The only calculation I can come up with which gives 1.6 would be 1.2 * 1/0.75, but it requires some pretty mixed up maths to get to that starting from "125% scaling". It's plausible though if somebody thought subtracting 1 from the devicePixelRatio and then doing some multiplications was the thing to do. -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 --- Comment #2 from Sven Brauch --- Hi, QWidget has a devicePixelRatioF which contains this 1.25 IIRC: https://doc.qt.io/qt-6/qpaintdevice.html#devicePixelRatioF -- I think that's what you need? -- You are receiving this mail because: You are watching all bug changes.
[gwenview] [Bug 465688] "Fit" on scaled wayland display doesn't fit
https://bugs.kde.org/show_bug.cgi?id=465688 Jorge changed: What|Removed |Added CC||jorge_barroso...@hotmail.co ||m --- Comment #1 from Jorge --- I have been able to reproduce this when using a display scale different from 100% and a screenshot (ensuring the same size as the display) The problem seems to come from DocumentView::toggleZoomToFit and DocumentView::toggleZoomToFill calling "d->setZoom(1., d->cursorPosition());" with "1." zoom, which should probably be a different value (i.e. 1.25 for 125% scale), but I'm unsure as to what's the best way to get the current display scale and apply it to the zoom level instead of a hardcoded "1." -- You are receiving this mail because: You are watching all bug changes.
