[Mageia-dev] why not disable bytecode interpreter in freetype2 ?

[Buchan Milne]

On Friday, 13 May 2011 17:28:24 Zé wrote:
> 2011/5/13 Buchan Milne <bgmilne at staff.telkomsa.net>:
> > On Friday, 13 May 2011 11:12:41 Zé wrote:
> >> 2011/5/13 Zé <mmodem00 at gmail.com>:
> >> > 2011/5/13 Dimitrios Glentadakis <dglent at gmail.com>:
> >> >> Στις Παρασκευή 13 Μάιος 2011 00:39:55 Zé γράψατε:
> >> >>> 2011/5/12 Dick Gevers <dvgevers at xs4all.nl>:
> >> >>> > On Thu, 12 May 2011 13:20:39 +0200, Dimitrios Glentadakis wrote
> >> >>> > about
> >> >>> 
> >> >>> perl -pi -e 's|#define TT_CONFIG_OPTION_BYTECODE_INTERPRETER|/\*
> >> >>> #define TT_CONFIG_OPTION_BYTECODE_INTERPRETER  \*/|'
> >> >>> include/freetype/config/ftoption.h
> >> >>> 
> >> >>> 
> >> >>> dont forget to also increase Release to avoid conflicts with
> >> >>> existant freetype2, and then build the package.
> >> >> 
> >> >> Why do all these things when you can simply add an entry in the
> >> >> font.conf file ?
> >> > 
> >> > Thats a fact, but hat should happen is that freetype2 should have
> >> > bytecode interpreter disabled by default, since so far users prefer
> >> > it.
> >> 
> >> Seams Fedora choosed to finally fix it, it reverted freetype2 with a
> >> patch to disable bytecode interpreter. ->
> >> https://bugzilla.redhat.com/show_bug.cgi?id=547532
> > 
> > No, this is not what is covered in this bug report.
> 
> Yes, correct i miss understood what as the bug report about.
> 
> > Firstly, here are the non-problems:
> > 1)The bytecode interpreter *can* make fonts look better, *if* they have
> > hinting in the fonts. Not all ttf fonts have hinting, but AFAIK all the
> > MS fonts *do* have hinting.
> > 
> > So, historically, the recommended approach was to use the PLF freetype
> > *if* you had imported MS fonts (e.g. from a dual-boot Windows
> > installation).
> 
> Well i always avoid using PLF freetype and for what i have read in
> ML's all the users that answered to it said that also avoid PLF
> freetype.
> 
> So far for hat i have seen, all users prefered like fonts were
> rendered wen patents were still valid...

Were *all* these users using *hinted* fonts? I think they weren't using hinted 
fonts at all.

> > 2)The Freetype autohinter was implemented later, and improves things for
> > unhinted fonts, but hinted fonts still looked better with the bytecode
> > interpreter.
> > 
> > 
> > This is the problem:
> > 3)If the bytecode interpreter was enabled, auto-hinting was disabled (or,
> > could be, for 'medium' and 'heavy' hinting settings) for unhinted fonts.
> > 
> > The Fedora bug isn't about disabling the bytecode interpreter, but by
> > still allowing auto-hinting for unhinted fonts if the bytecode
> > interpreter.
> > 
> > *This* is the right fix. Your insistence to *disable* the bytecode
> > interpreter (leaving users with *no* options, in case they need hinted
> > fonts) is the wrong fix.
> 
> Well this way users cant also set to have autohint, seams theres
> always some app failing.

?

We need to apply the patch that enables the autohinter for unhinted fonts, 
even if the bytecode interpreter is enabled, that is available from the bug 
report for which you provided the link.

> Why not having it disabled by default?

So, you haven't read what I wrote in (3)?

> users will always be able to
> set their preferences about using or not autohint, but that way
> ensures that all fonts are better rended.

No, you ignore the case where some hinted fonts are almost unusable without 
the bytecode interpreter, and others where they are rendered better.

> All this came up after patents end in wich showed users how fonts
> appear poor rended, until that point i didnt saw any complains about
> fonts, and this is what should be fixed.

You contradict yourself ... and you can't make blanket statements of "how 
fonts appear poor rended", as it depends on the font (and whether it is hinted 
or not).

Regards,
Buchan