Re: [ft] Regression in rendering quality with subpixel antialiasing

[Bernd Schubert]

Hello David,

On Thursday 21 September 2006 07:02, David Turner wrote:
> > Psst, if Steve reads this it really might happen. Then, after the update
> > to Etch about 40 group members will complain about blurry fonts and in
> > end I have to regularily recompile another package... (though probably I
> > won't be in this group anymore that time).
>
> Most other distributions have *not* enabled the bytecode interpreter, and I
> don't see many people screaming about it. For the difficult ones, simply
> explain them that it has been disabled exactly for the same reason why MP3
> playback oe DVD decoding are not available by default and need tweaks.

Um, I have to admit that I simple added the marillat archive into our 
sources.list, so there's everything available. Anyway, if Christian Marillat 
wouldn't do his really great work, I wouldn't care much about the multimedia 
stuff on our institut systems, its just not required for our work. However, 
we are looking all the day on the screen and are programming, writing 
articles, etc., so good fonts are really neccessary.

Anyway, I will discuss this with Steve, maybe we can create two libfreetype6 
packages - one in the main archive without bytecode and one in non-free with 
bytecode..

>
> > [...]
> > However, I already wrote in my first mail, that full subpixel hinting
> > doesn't
> > entirely help e.g. with OpenOffice. I have uploaded two new shots.
> >
> > http://www.pci.uni-heidelberg.de/tc/usr/bernd/downloads/freetype-snapshot
> >s/3-old_full_sub.png
> > http://www.pci.uni-heidelberg.de/tc/usr/bernd/downloads/freetype-snapshot
> >s/3-new_full_sub.png
> >
> > I think you can see that 3-old_full_sub.png looks better than
> > 3-new_full_sub.png. Do you have an idea whats going on?
>
> Obviously, the "old" one is using bytecode interpretation, while the "new"
> one is the result of auto-hinting. I don't know much about OpenOffice
> though

Ah, for me this is absolutely not so abvious, I only see two different font 
graphs and one is a bit more blurry than the other ;)

May I ask you for some basic help with libXft, libfreetype and libfontconfig? 
So far I don't even know about there relations to each other. I guess a 
program does a function call to libxft and libxft does a function call to 
libfreetype to finally render the font, doesn't it? But who of them is 
calling libfontconfig, libxft or libfreetype?
Hmm, a 'ldd soffice.bin' shows me that it is not linked to libXft. So either 
my guess to the function call order is wrong or OpenOffice really calls 
freetype functions without libXft.
Is there a typical function call to libfreetype? I would just like to compare 
what openoffice does differently.

Thanks,
Bernd


-- 
Bernd Schubert
PCI / Theoretische Chemie
Universität Heidelberg
INF 229
69120 Heidelberg