Hi, after upgrading libreoffice on my SLED 15 SP6 from 24.2.1.2 to 24.8.1.2 we realized that font rendering has changed and fonts get rendered more fuzzy/blurry than before. The same 24.8.1.2 worked fine on SLED 15 SP5 and it turned out that was due the libcairo version. After some debugging the situation is as follows: - libreoffice up to 24.2.7.2 works fine with libcairo2-1.16.0 (as shipped with SP5) and with libcairo2-1.18.0 (and the latest 1.18.2) as shipped with SP6. - libreoffice starting with 24.8.0.1 and up to the latest release, all taken from the libreoffice download page, work fine with libcairo2-1.16.0 but show blurry/fuzzy fonts with libcairo2-1.18.0/2. What I mean by "fine" vs. "blurry" can be seen in the screenshots. The lines "1.16" show how it looks like with libcairo2-1.16.0 and all libreoffice versions, but also for libreoffice 24.2.x and libcairo2-1.18.x. The lines marked with "1.18" are for libcairo2-1.18.x and libreoffice 24.8.x. Note: "LD_PRELOAD=/tmp/libcairo.so.2.11600.0" is enough to revert the behaviour for libreoffice 24.8.x. to the previous, fine rendering. lo1.png shows Arial/Liberation Sans without any special environment variables. You can see that libreoffice 24.2 as well as libcairo2 1.16 make every H rendered the same way, while LO 24.8 + libcairo2 1.18 render the same letter in different ways every 1-2 letters (depending on the font size). lo2.png shows the situation with "export SAL_ALLOW_DEFAULT_HINTING=true" and "Xft.hintstyle: hintfull" in ~/.Xresources, i.e. activating the patch that I wrote with Caolán McNamaras help back in 2023. This causes crisp-clear rendering for LO 24.2 or libcairo2 1.16.10 but blurry letters with 24.x and 1.18.x due to that changing rendering. That causes texts to appear a little more fuzzy and makes them harder to read (lo4.png), especially for very small sizes (lo3.png). It's not much difference in lo4.png, but that's how we detected it when our users complained it was harder to read their texts. So there must be some change in LO 24.8.x that only changes font rendering with libcairo2 1.18, but not with libcairo2 1.16. It does not depend on the graphics card, we tested with nvidia anad Ati with differents drivers, and even with NX and a framebuffer device. Is this change intended? To me it doesn't seem reasonable to render the same letter in different ways, does it? Has anyone an idea what patch could have caused this change, so I get an idea where I can start looking to debug this in the libreoffice code? Thanks a lot! Frank -- Dipl.-Inform. Frank Steiner Web: http://www.bio.ifi.lmu.de/~steiner/ Lehrstuhl f. Bioinformatik Mail: http://www.bio.ifi.lmu.de/~steiner/m/ LMU, Amalienstr. 17 Phone: +49 89 2180-4049 80333 Muenchen, Germany Fax: +49 89 2180-99-4049 * Rekursion kann man erst verstehen, wenn man Rekursion verstanden hat. *
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