[Fontconfig] Another proposal for saving custom fonts in fontconfig

[Akira TAGOH]

On Wed, Jun 26, 2019 at 8:49 PM Nicolas Mailhot
<nicolas.mailhot at laposte.net> wrote:
>
> Le 2019-06-26 12:16, Akira TAGOH a écrit :
>
> > Indeed, it looks like feasible like what you said. but if I understand
> > correctly, it isn't a custom family name for varfonts but style name.
> > Though I doubt how one can effectively name it less than actual
> > parameters of fontvariations.
>
> Then I'd expect something like:

Right. the sort of. and that is what I wrote in my first mail. but
those confugration things aren't applied to FcFontList() otherwise no
advantages in it at all.
Anyway, we need more detailed use cases and requirements on this
proposal to discuss on it furthermore. let's wait on it.

>
>    <match target="scan">
>      <test name="fullname">
>        <string>original starting point</string>
>      </test>
>      <edit name="family">
>        <string>clean family name</string> (if necessary; quite often,
> will be ne necessary)
>      </edit>
>      <edit name="style">
>        <string>clean original style, with default axis values</string>
> (if original style needs changing; alternatively, some way to hide the
> default style)
>      </edit>
>      <add name="style">
>        <string>synthetic style1</string>
>        <axis>
>          <string>axis name</string>
>          <double>axis value</double> (if double is the correct thing
> here)
>        </axis>
>      </add>
>      <add name="style">
>        <string>synthetic style2</string>
>        <axis>
>          <string>axis name</string>
>          <double>axis value</double>
>        </axis>
>      </add>
>      <edit name="fullname" value="auto"/>
>    </match>
>
> The main fontconfig syntax change to do such things reliably is
>    <edit name="fullname" value="auto"/> ← compute the correct fullname,
> using WWS rules, for family + style
>
> which should probably have
>    <edit name="family" value="auto"/>  ← derive the correct family from
> fullname, using WWS rules
>    <edit name="style" value="auto"/>   ← derive the correct style  from
> fullname, using WWS rules
>
> Because what makes such operations fail is practice, is the way family
> and style need to be defined both in fullname and family and style, and
> people + software keep making mistakes doing just one of them, or
> specifying inconsistent values at both layers.
>
> *if* fontconfig was smart enough, and upstream naming was clean, it
> could be simplified into
>
>    <match target="scan">
>      <test name="family">
>        <string>family to operate on</string>
>      </edit>
>      <unset name="style"/>
>      <add name="style">
>        <string>synthetic style1</string>
>        <axis>
>          <string>axis name</string>
>          <double>axis value</double>
>        </axis>
>      </add>
>      <add name="style">
>        <string>synthetic style2</string>
>        <axis>
>          <string>axis name</string>
>          <double>axis value</double>
>        </axis>
>      </add>
>      <edit name="fullname" value="auto"/>
>    </match>
>
> (if fontconfig is able to autoselect, the original style most closely
> matching the synthetic to add, without needing a fullname help)
>
> --
> Nicolas Mailhot



-- 
Akira TAGOH