[isabelle-dev] Isabelle DejaVu against old Isabelle Text font
makarius at sketis.net
Tue Feb 5 20:19:13 CET 2019
On 05.02.19 11:43, Peter Lammich wrote:
> I just updated my Isabelle devel version (now on d21789843f01), and
> immediately noticed that the displayed fonts are significantly blurry.
> Find attached a side-by-side comparison of Isabelle-d21789843f01 (left)
> and Isabelle-2018 (right). At least on my monitor, the font display on
> the left side is significantly worse (blurred). Both use font size 18
> with standard anti-aliasing method.
> Is this worsening due to another Java version, due to the new Isabelle
> font, or has it some other reasons? How to find out?
From a distance, I would say that this is a matter of the Java 11
font-renderer, which is provided by https://adoptopenjdk.net. The one by
Oracle is much worse -- OpenJdk not the non-free Java. (Note that the
license change of non-free Oracle Java no longer allows to bundle it.)
You can find out yourself by trying the IsabelleText font that is
distributed with Isabelle2018: the ttf files need to go into ~/.fonts on
Ubuntu; or elsewhere on other systems. It is important to remove the
fonts after the experiment!
Generally, the new fonts should be slightly better than before: the
quality should be that of the original Deja Vu fonts without any
censorship. I merely trim it to a well-defined collection of glyphs and
add our Isabelle math symbols from the TeX family -- see "isabelle
build_fonts" (e.g. in Isabelle/2c3e5e58d93f).
> How to fix it?
You know already that "fix" and "bug" is not in my vocabulary -- I don't
use such street language.
On up-to-date UHD displays the quality should of the new Java 11 + new
fonts should be higher than ever before, so you can improve your overall
situation by getting a new display. My huge UHD display at home was
actually quite cheap: approx. 350 EUR.
I do see the slight blurring on my ancient HD Sony Vaio from 2013, but I
am not using that very often. Buying a new laptop is certainly more
expensive than just a display -- nonetheless I am surprised how many 100
EUR displays are still standing on desks and stared at every day.
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