[Fontconfig] Why does family under `Best score` differ from that under the preceding `Match Pattern`?

[Kynn Jones]

On Mon, Mar 7, 2016 at 6:27 PM, Raimund Steger <rs at mytum.de> wrote:
> On Sun, 6 Mar 2016 21:22:09 -0500
> Kynn Jones <kynnjo at gmail.com> wrote:
>> [...]
>> TeX Gyre Chorus 0 0 0    1 0 0 1001 0 1 1002 0 0 0 0 1      1 1 1 0 0
>>   1 2.14735e+12
>>        Terminus 0 0 0 1001 0 0    1 0 1 1002 0 0 1 0 1 100001 1 1 0 0
>> 1001 2.14748e+12
>>
>> Supposedly the score for `TeX Gyre Chorus` is the better one, but I
>> cannot tell why.  Nor can I tell what the various components
>> correspond to.  I have not been able to find any documentation about
>> any of this.
>
> It's not guaranteed to remain stable, i.e. not part of the public API.
>
>>
>> Both score vectors ave have 22 components, AFAICT `_FcMatcherPriority`
>> has 25 components:
>
> PRI_END is just a marker for the last enum element. Also, it depends on fontconfig version. Recent fontconfig's should print a 24-element vector. fontconfig-2.11 (which seems to be the version you're using) has three properties before 'scalable' because it still has FC_HASH. Also, it doesn't have 'color' nor 'symbol' or 'size', all of which were later commits. Hence 22.
>
> 0 in a vector element means that the property couldn't be matched (wasn't in the pattern). 1 means good match, everything higher is worse.

Thanks for the information.  It's very helpful.

kj