[devel] XLFD font naming convention

[Lucien Gentis]

Le 04/03/2019 à 16:20, Ilya Anfimov a écrit :
> On Fri, Mar 01, 2019 at 06:09:02PM +0100, Lucien Gentis wrote:
>> Hi,
>>
>> When in an X application, we call (with 14 fields) :
>>
>> XListFonts(serveur, "-*-*-*-*-*-*-0-0-*-*-*-0-*-*", 10000, &nbFonts);
>>
>> we get scalable fonts with fields 7,8,12 at "0" like :
>>
>> -bitstream-charter-medium-i-normal--0-0-75-75-p-0-iso8859-1
>> -dec-terminal-medium-r-normal--0-0-75-75-c-0-dec-dectech
>>
>> but if we call :
>>
>> XListFonts(serveur, "-*-*-*-*-*-*-0-*-*-*-*-*-*-*", 10000, &nbFonts);
>>
>> we also get fonts with only field 7 at "0" like :
>>
>> -bitstream-charter-bold-r-normal--0-120-100-100-p-0-iso8859-1
>> -adobe-new century schoolbook-bold-r-normal--0-120-100-100-p-0-iso10646-1
>>
>> what about these fonts ?
>   Well, X Logical Font Description Conventions
>                  Version 1.5
> 		says (section 5):
>
>    "For a scalable font source, a scalable font name for each
>    character set is included in the list.  In addition to
>    the scalable font name, specific derived instance names
>    may also be included in the list."
>    ...
>    "Because some existing applications rely on seeing a collection
>    of point and pixel sizes, server vendors are strongly
>    encouraged in the near term to provide a mechanism for
>    including, for each scalable font name, a set of specific
>    derived instance names. For font sources that contain a set of
>    specific derived instance names."
>
>   So  it  is OK to have that in font list. It must be --0-0-  base
> name for every such font, and if it is not -- there is  an  error
> somewhere in your X server or font server, and probably should be
> fixed. If there are base entries -- then you  don't need them.
But how to determine if a font is scalable or not when its fields 7, 8 
and 12 are not at "0" ?
>
>> It's told in doc that scalable fonts must have their fields 7, 8 and 12 at
>> "0"
>>
>> _______________________________________________
>> xorg at lists.x.org: X.Org support
>> Archives: http://lists.freedesktop.org/archives/xorg
>> Info: https://lists.x.org/mailman/listinfo/xorg
>> Your subscription address: %(user_address)s
> _______________________________________________
> xorg at lists.x.org: X.Org support
> Archives: http://lists.freedesktop.org/archives/xorg
> Info: https://lists.x.org/mailman/listinfo/xorg
> Your subscription address: %(user_address)s