Wayland Protocol Finally Ready For Fractional Scaling

[darkbasic]

By the way color calibration protocol just got promoted to staging!

[mario995]

Good, but GTK itself doesn't support fractional scaling. And they have been clear on that - they won't support it.

So there's no chance Gnome will have the correct fractional scaling support without blur effect for exmaple in Nautilus or other Gnome-apps? Even on Wayland?
Gnome is my favourite DE, but I have small 15'6 laptop and without fractional scaling everything is too small for me. Making font size bigger looks ugly.

[billyswong]

My current experience with HDR outside Linux is this: 4K TV and Google Chromecast 4 both say they support HDR, Streaming apps also promise they're good at it, toggles are switched on where needed, yet most of The Rings of Power scenes is happening in too-black-to-understand brightness ranges while Elven whiteglow faces loose their noses.

If that's what the HDR megaproductions have to offer I'll keep disabling HDR and tweaking brightness, alpha and etc to be able to actually enjoy the full views.

I'm sure a better HDR exists somewhere, but it's definitely not in "HDR" IPS TV screens sold in 3rd-world, which so far have failed to live up to a plain non-HDR IPS PC monitor contrast.

Well, the "99% P3" I mentioned are already top-grade monitors. For most "HDR" monitors, they are "HDR" in name. Their only capacity is reading HDR video signal then render it on their SDR quality 8-bit LCD hardware, maybe combined with a brighter backlight and that's it.

Even for those who gain fancy badges such as "HDR 600", it is often still the same hot garbage but this time the backlight is "zoned" into a number of partitions so bright regions of the scenery may shine brighter by the backlight. It is easy to foresee the result is always less than ideal - the bright region size and shape isn't going to fit the backlight partitioning.

And one can forget colour accuracy in those kind of fancy monitors.

[regs]

Yeah, but isn't fractional scaling UI stuff?

As said above, scaling is done by the app itself or by widgetset. Win32, for example, does not scale itself. It only have a compatibility option to raster scale windows in case if they can't scale themselves. It's something similar to XWayland, but Windows allows you to choose it per application. So if you need native output or your app can scale itself you can let it do that. Wayland doesn't offer that option.

Now on the scaling. Scaling is a function that returns dimensions adjusted to active screen PPI. So it passes all physical dimensions (like width, height, top, left positions, border size and all other sizes) before rendering them. qt has it built in and can do fractional scaling by 1.25, 1.5, 1.75, 2.5 etc. Win32 doesn't, so all application using Win32 widgetset actually have own scaling functionality. GTK can only do integer scaling. But the main problem is GDK. It does not offer you any way to know whatever you can scale yourself or can't, and even if you do, it won't offer you any way to know how much you should apply, as there is no any active PPI. It always returns around 96, even if it's 144 or 192. You might rely on monitor physical dimensions given in millimeters, but it's often wrong. And all other dimensions GDK already return adjusted by own wrong way. So GDK3 is flawed by design. It neither scale itself, neither let apps scale themselves.

[Quackdoc]

Yeah, but isn't fractional scaling UI stuff?

the fractional scaling protocol is how you tell the app to scale, so mutter needs to tell gtk, qt etc. "Hey, I want you to scale by 120% (1.2x)" then the app can give the scaled surface or in the case of gtk, not give you the fractional scaled surface

[MetalGearDaner]

mutter is merely for handling applications, while GTK is for making UI stuff

Yeah, but isn't fractional scaling UI stuff?

[Quackdoc]

Awesome, thank you! Apparently GNOME Mutter is already working on implementing the new protocol. I'm confused about what are the different roles of the compositor (Mutter) and the toolkit (GTK) regarding fractional scaling.

mutter is merely for handling applications, while GTK is for making UI stuff

[MetalGearDaner]

https://gitlab.gnome.org/GNOME/gtk/-/issues/4345

Awesome, thank you! Apparently GNOME Mutter is already working on implementing the new protocol. I'm confused about what are the different roles of the compositor (Mutter) and the toolkit (GTK) regarding fractional scaling.

[Quackdoc]

Would you mind sharing where is that stated? Any idea what's the rationale behind that decision? It would be nice for GTK to reconsider now that Wayland incorporates this new protocol.

https://gitlab.gnome.org/GNOME/gtk/-/issues/4345

[MetalGearDaner]

Good, but GTK itself doesn't support fractional scaling. And they have been clear on that - they won't support it.

Would you mind sharing where is that stated? Any idea what's the rationale behind that decision? It would be nice for GTK to reconsider now that Wayland incorporates this new protocol.