Bug 285320 – [GTK] bad font rendering in 2.46

• Component: WebKitGTK
• Status: NEW

Created attachment 473752 [details]
Comparison screenshots

I recently upgraded from 2.44 to 2.46 and I immediately noticed degraded font rendering. To give some context, I'm using Evolution 3.52.4 with WebKitGTK 2.46.5; the sans-serif font is "Inter Variable Regular" at 10.5 and the monospace one is "JetBrains Mono NL SemiBold" at 10.

The main problems I noticed are the following:

  - Fonts are too thin on light theme, too thick on dark theme. On the light variant in particular, the sans font is really tiring to read.
  - Font features, such as alternative symbols, are not considered.

Please take a look at the attached picture to see the difference.

Downgrading to 2.44 fixes those problems.

[Michael Catanzaro]

Notably 2.44 uses cairo and 2.46 uses skia, so they're not expected to look similar.

(No comment on whether the changes are desirable or not.)

[Jim Mason]

(In reply to shibotto from comment #0)
>   - Fonts are too thin on light theme, too thick on dark theme. On the light
> variant in particular, the sans font is really tiring to read.

I am seeing this as well.  I've attached three screeshots, showing a sample page in WebKitGTK cairo, WebKitGTK skia, and Firefox 128 esr.  Note the fonts in WebKitGTK cairo and Firefox are consistent, whilst the font rendering with WebKitGTK skia is dodgy.

I may be mistaken, but I believe Firefox also uses skia for rendering; if so, somehow they have the font rendering working in a good way.

[Jim Mason]

Created attachment 473893 [details]
WebKitGTK skia

[Jim Mason]

Created attachment 473894 [details]
WebKitGTK cairo

[Jim Mason]

Created attachment 473895 [details]
Firefox 128 esr

[Jim Mason]

Created attachment 473896 [details]
WebKitGTK skia

Thanks, I've now seen the "what's new in ..." blog post. It says that Cairo is supposed to be removed eventually, but that it is still present for architectures not supported by Skia yet. Until this gets figured out, is it possible to manually select it on architectures where Skia is the default too?

[Michael Catanzaro]

Sure, there is a USE_CAIRO build flag. Certainly not recommended though.

I agree, it's not a long term solution and I'd very much prefer not having to do it, even just for the build time. I'm not capable of helping improve Skia by contributing code, but if there is anything you'd like feedbacks on, such as patches and the likes, I'm at your disposal (just mind that it takes 6h+ to build WebKitGTK with Skia on my system, so please be patient).
Regarding the build flag, USE_CAIRO didn't seem to make a difference, digging in that direction however I found USE_SKIA and that did the trick.