[Okular-devel] [PATCH] Fix rendering of DVI documents

[Elvis Stansvik]

2009/10/2 Albert Astals Cid <aacid at kde.org>:
> A Divendres, 2 d'octubre de 2009, Benoit Jacob va escriure:
>> Hi List,
>>
>> I noticed that the rendering of DVI documents was broken exactly in
>> the same way as what I observed with PDF documents, namely, it used
>> auto-hinting which looks especially bad with TeX fonts.
>>
>> Attached is a 1-line patch that changes it. I need your permission to
>>  commit.
>>
>> Screenshots:
>> * original :
>>  http://picasaweb.google.ca/lh/photo/fry54ANy23UesNpFhbWanA?feat=directlink
>>  * fixed :
>>  http://picasaweb.google.ca/lh/photo/OjQIZ7Of6wP74k7fKUwXTw?feat=directlink
>>
>> Here are some comments before one objects that disabling hinting is
>> just a matter of taste, etc.
>>
>> First, it's obvious that the "original" screenshot linked above is
>> horrible and that the "fixed" is the one that looks good.
>>
>> Second, it is a consensus on the Poppler/PDF side that one should use
>> no hinting, and then, there's no reason why DVI should be any
>> different. To summarize the situation on the PDF side:
>> * poppler/cairo (hence Evince) 's code completely disables hinting
>> * poppler/splash (hence Okular) 's code _meant_ to completely disable
>> hinting (actually only auto-hinting, but in the context of DVI that's
>> really the same because almost all DVI files use Type 1 fonts, and
>> bytecode only exists in TrueType fonts). It was a clear bug in the
>> code, where it was clear that the code didn't do what it intended,
>> that resulted in hinted fonts being used.
>>
>> Third, the old KDVI used to not do any hinting, I'm completely sure of
>> that because I've spent hundreds of hours looking at documents in it.
>> I remember distinctly the (imho beautiful) slightly fuzzy look of the
>> TeX fonts in it, that is characteristic of non-hinted text, although
>> at that time I didn't know about hinting. That said, I used "svn
>> annotate" to see who enabled hinting in the C++ code, and it turns out
>> to be Stefan Kebekus himself in an old revision (240000-something). I
>> am puzzled about that, but I still maintain that KDVI didn't use
>> hinting on all the Linux systems that I tried. My best guess is that
>> Stefan Kebekus _thought_ that he had enabled hinting but for some
>> reason it wasn't used. I haven't investigated further as this is quite
>> intricate, and of course I only have Okular's code at hand, I haven't
>> looked at the actual KDVI code.
>>
>> OK to commit?
>
> No, actually what it is clear that *you* don't like hinting, and you have a
> certain amount of followers, the problem is that typically people that is
> happy with a setting is not much active defending it because they are happy in
> their sofas.
>
> My suggestion is adding a configuration option that lets the user choose
> between "No Hinting", "Hinting" and "Hinting as set in KDE settings". For KDE
> 4.3.x we can add it, it set in "Hinting" and the only configuration option
> will be thought non GUI as we can't add translatable texts. For KDE 4.4.x we
> can default to "No Hinting" if others here (basically Pino, Brad, Tokoe)
> agree.

I'm not one of those three, but I'll just chime in anyway and say that
I agree with Benoit that, at least in the example he gave, it's very
obvious that the non-hinted version looks much better. I'm not trying
to troll here, but come on, in some places the hinted one is hardly
readable, the characters are all jumpy; e.g. the 'T' in the very first
word. I don't know if this is a bug in the hinting or just the way
it's supposed to look.

Anyway, this doesn't make me a "follower" of Benoit; I'm just calling
it like I see it ;)

Cheers,
Elvis

>
> Comments?
>
> Albert
>
>>
>> Benoit
>>
>
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