[isabelle-dev] Isabelle DejaVu against old Isabelle Text font

Peter Lammich lammich at in.tum.de
Sun Feb 10 20:08:04 CET 2019


No luck on my machine. The font rendering still looks slightly
blurred. 

However, I'm using an old Linux (Ubuntu 16.04) ... may that be the
reason?

--
  Peter


On So, 2019-02-10 at 20:01 +0100, Christian Sternagel wrote:
> This is just to confirm that the result looks really great on my
> linux
> (Fedora 29 with i3) setup. Thanks!
> 
> chris
> 
> On 2/10/19 7:47 PM, Makarius wrote:
> > 
> > On 08/02/2019 10:03, Christian Sternagel wrote:
> > > 
> > > 
> > > I am glad to hear that others have the same experience, I thought
> > > my
> > > eyes were going bad ;)
> > > 
> > > But seriously, "buy a new screen" is not always possible. For
> > > example,
> > > in the upcoming summer term I am teaching an Isabelle class at
> > > the
> > > University of Innsbruck. In my experience (and I just reconfirmed
> > > this
> > > for the room I will be teaching in), the projectors we have here
> > > a
> > > typically rather old (and have low resolution, but that is a
> > > different
> > > story).
> > > 
> > > At the moment there is a palpable difference (font rendering
> > > crispness
> > > wise) between using Isabelle2018 with projector (which I will do
> > > anyway
> > > for my class) and some recent development version (sorry I didn't
> > > note
> > > down what changeset I used for testing my setup).
> > Classic JDK 8 from Oracle and OpenJDK 11 (e.g. from AdoptOpenJDK)
> > are
> > different in many ways, and it is definitely required to get used
> > to the
> > new look of font rendering. (For me Isabelle2018 already looks very
> > strange.)
> > 
> > With proper parameters -- in software and hardware -- fonts should
> > come
> > out better than before.
> > 
> > 
> > First of all, sub-pixel rendering should be enabled, see this NEWS
> > entry
> > from Isabelle/f714114b0571 (25-Oct-2018):
> > 
> >   *** Isabelle/jEdit Prover IDE ***
> > 
> >   * Improved sub-pixel font rendering (especially on Linux), thanks
> > to
> > OpenJDK 11.
> > 
> > (In Java 8, sub-pixel rendering made things worse.)
> > 
> > Since that that NEWS entry is a bit too implicit, I have now
> > changed the
> > default to enable "Subpixel HRGB" always on all platforms
> > (Isabelle/f610115ca3d0). I have checked my usual test machines for
> > Windows and macOS, to see that it all looks fine.
> > 
> > 
> > Secondly, I have done some more research on FreeType, the renderer
> > used
> > for OpenJDK on Linux. It appears that the DejaVu family gets some
> > special treatment if it shows up under its original name, but not
> > if it
> > is a renamed copy. So I have fine-tuned the Isabelle DejaVu fonts
> > in
> > Isabelle/4791988fcbc4 to impose the FreeType auto-hinting
> > beforehand to
> > the TrueType file: this leads to isabelle_fonts-20190210 in
> > Isabelle/7e5a7a11d5d1.
> > 
> > 
> > In summary:
> > 
> >   * Isabelle font rendering should be once again slightly better on
> > Linux.
> > 
> >   * There is a small risk that it has slightly degraded on Windows
> > and
> > macOS.
> > 
> > In other words: early adopters should look closely if it is all
> > fine. We
> > are (very slowly) moving towards the Isabelle2019 release
> > (presumably
> > June 2019), and everything needs to be beyond doubt when released.
> > 
> > 
> > 	Makarius
> > 
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