[PATCH 0/4] Fix and improve Freetype/Fontconfig support

[Andrew Hughes]

----- Original Message -----
> Hello Andrew...
> 
> On 29/12/16 06:22, Andrew Hughes wrote:
> 
> > I'll open a bug for getting these into 3.3.0.
> 
> Great. Is there currently an estimate for when 3.3.0 will released or at
> least be prepared? (rcs, ...)
> 

I recalled there was a bug about this... turned out it was yours :P

http://icedtea.classpath.org/bugzilla/show_bug.cgi?id=3271

We were going to do 3.3.0 for u112, but with the OpenJDK 6 security update taking
so long, we'll do it for u121 over the next week.

> > Can you elaborate on what kind of option you would expect the new version
> > to use and what tests would be required to ensure it will build and run
> > correctly against the installed FreeType?
> > 
> > Currently, we detect if TT_CONFIG_OPTION_SUBPIXEL_HINTING is set to
> > anything
> > other than zero. This can mean infinality support is installed, or just
> > the new stripped-down 2.7 version.
> 
> The infinality patches for OpenJDK never used any special Freetype nor
> Fontconfig functionality and thus doesn't depend on it. It just seemed
> that way when people started reporting problems against vanilla versions
> due to the reasons explained in my patches.
> 
> So, basically, there are no special requirements for either Freetype nor
> Fontconfig. Both have to be installed -- that's it.

Oh ok. That's not the impression I'd been given. It makes things a lot simpler.

> 
> With regards to version requirements, I would have to check closely if
> there is any cut-off where the current implementation relies on details
> that have been introduced to either Freetype or Fontconfig from a
> specific version upwards. But judging from the age of the patches, I
> don't think that is relevant anymore.
> 
> On my part, I tested with Freetype 2.6.3 and 2.7 and Fontconfig 2.12.1.
> Judging from the Changelog of Fontconfig, v2.11.95 would be a good
> starting point for support since it introduced the hint style templates.

I guess we wait and see if anyone hits problems with an old version that's
still around. That's likely to happen more if we also backport this to 7,
which it sounds like we should.

> 
> With Freetype itself, it should be the same version requirements that
> OpenJDK currently has. It really uses no fancy new stuff. I simply gets
> appropriate font configuration through Fontconfig and sets them through
> Freetype.
> 
> Last but not least, I would suggest a simple --with-fontconfig option
> for configure and the corresponding HAVE_FONTCONFIG or alike as a
> symbol. That follows the established semantics, afaik.
> 

Well, every setup should really have fontconfig, even without these changes.
What we need is an option to turn on this enhancement, such as --enable-x.
What would be an appropriate description for it? --enable-improved-font-rendering?

The --with-x syntax is meant to take an argument, so --enable/--disable
seems more appropriate here.

> > Are you open to maintaining this going forward?
> 
> Sure. Do you have anything special in mind?

No, just someone to fix any bugs that come up and generally avoid it bit-rotting.

> 
> > I think it should have some time to soak before we> consider enabling it
> > by default again.
> 
> That's fine with me... as long as at least a few people test it and find
> problems that I have actually missed along the way. ;-)

Yeah, I'm thinking put it in now, but enable by default for 3.4.0 in April.

> 
> By the way, a few of those patches do also apply to OpenJDK and are not
> specific to the fontconfig support. Is there any chance of getting those
> upstream? Or will this always imply having to sign a OCA?

Yes, you'd have to sign an OCA. It's also probably going to have to wait
until they release 9 and start on 10, as I believe only regression fixes are
being accepted at the moment.

Hopefully, a jdk10 set of repos will be forthcoming soon.

> 
> Thanks,
> Matthias
> 
> --
> Dipl.-Inf. (FH) Matthias Dahl | Software Engineer | binary-island.eu
>  Hire me for contract work: Open Source, Proprietary, Web/Mobile/Desktop
> 

-- 
Andrew :)

Senior Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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