[Fontconfig] any possible trouble by adding lang to the pattern by default

[Akira TAGOH]

Is there any more comments and concerns on this? if not, I'll commit
the changes into master though.

On Tue, May 22, 2012 at 2:34 PM, Akira TAGOH <akira at tagoh.org> wrote:
> For the reference of what I want to address:
> http://cgit.freedesktop.org/~tagoh/fontconfig/commit/?h=add-lang-to-pattern
>
> $ LANG=ja ./fc-match/fc-match
> VL-PGothic-Regular.ttf: "VL Pゴシック" "regular"
> $ LANG=zh_CN ./fc-match/fc-match
> wqy-zenhei.ttc: "文泉驿正黑" "Regular"
> $ LANG=en_US ./fc-match/fc-match
> DejaVuSans.ttf: "DejaVu Sans" "Book"
> $ FC_DEBUG=4 FC_LANG=ja:zh-cn LANG=en_US ./fc-match/fc-match
> ...
> FcConfigSubstitute Pattern has 1 elts (size 16)
>        lang: "ja"(w) "zh-cn"(w)
> ...
> VL-PGothic-Regular.ttf: "VL Pゴシック" "regular"
> $ FC_DEBUG=4 FC_LANG=ja:zh-cn LANG=en_US ./fc-match/fc-match :lang=en
> ...
> FcConfigSubstitute Pattern has 1 elts (size 16)
>        lang: en(s) "ja"(w) "zh-cn"(w)
> ...
> DejaVuSans.ttf: "DejaVu Sans" "Book"
>
> On Tue, May 22, 2012 at 1:54 PM, Akira TAGOH <akira at tagoh.org> wrote:
>> On Tue, May 22, 2012 at 12:14 PM, Keith Packard <keithp at keithp.com> wrote:
>>> Are you trying to make fontconfig select an appropriate font without any
>>> language hints at all, based solely on the codepoints within the text?
>>
>> No, not really. that way takes too much cost to estimate. my
>> suggestion is simple. the complaint what I've ever seen about this was
>> it from the users who prefer to see only strings in English. i.e. set
>> $LANG to any English locale and $LC_CTYPE to the native one say.
>>
>> So it could be used to guess from it or anything else what languages
>> they prefer/are expecting to use the font for when any codepoints
>> conflicts to other languages, and they might obtain the better font by
>> applying it to the pattern in fontconfig side.
>>
>>> If so, then what I do myself is to configure a *set* of languages
>>> instead of a single one in my fontconfig setup. This effectively creates
>>> a multi-lingual "locale" for the purposes of font selection, guiding
>>> fontconfig to prefer fonts for my favored languages.
>>
>> Yes, the concept of the FC_LANG environment variable that I wrote as a
>> reference from bugzilla in the previous mail is the same with it. and
>> applying it to the pattern prior to do something with
>> FcConfigSubstitute() may be a bit aggressive here.
>>
>> --
>> Akira TAGOH
>
>
>
> --
> Akira TAGOH



-- 
Akira TAGOH