1959058 - [HDR] Seams in text when using widget.wayland.fractional-scale.enabled

Status: NEW

(Core :: Widget: Gtk, defect)

Description

[Vlad Zahorodnii [:zzag]]

Attachment: Screencast_20250408_121105.webm

Comment 1

[Vlad Zahorodnii [:zzag]]

When using fractional scaling (125%) + gfx.webrender.compositor.force-enabled, some text has seams sometimes. See the attached screencast. I've enabled gfx.webrender.compositor.force-enabled and widget.wayland.fractional-scale.enabled in about:config. I use Inter font face.

Desktop environment: Plasma Wayland
Firefox: 137.0

Comment 2

[Vlad Zahorodnii [:zzag]]

Attachment: Screenshot_20250408_121012.png

Comment 3

[Vlad Zahorodnii [:zzag]]

The link of the web page in the screencast is https://invent.kde.org/plasma/kwin/-/merge_requests/7438

Comment 4

[Martin Stránský [:stransky] (ni? me)]

Is that latest nighty?

Comment 5

[Martin Stránský [:stransky] (ni? me)]

Which screen resolution/scale do you use?

Comment 6

[Martin Stránský [:stransky] (ni? me)]

Also have you set widget.wayland.fractional-scale.enabled ?

Comment 7

[Vlad Zahorodnii [:zzag]]

(In reply to Martin Stránský [:stransky] (ni? me) from comment #6)

Also have you set widget.wayland.fractional-scale.enabled ?

No, I don't have it enabled.

Edit: sorry, no, I had it enabled

Comment 8

[Vlad Zahorodnii [:zzag]]

(In reply to Martin Stránský [:stransky] (ni? me) from comment #5)

Which screen resolution/scale do you use?

3840x2160 with a scale factor of 125%

Comment 9

[Martin Stránský [:stransky] (ni? me)]

widget.wayland.fractional-scale.enabled is not supposed to work on HDR mode at all. Even integer scale factor doesn't work correctly due to WebRender limitations (Bug 1731895).