Re: Problem with "fontdata.cache" being set to "no" in font-def.lua

[Hans Hagen <pragma@wxs.nl>]

Yanrui Li wrote:

>> the cache option mentioned there is not meant for using, just for debugging
>> (i.e. for myself)

> I have printed the the shared descriptions with the following code fragment:
> 
> function f4zhcn.pre_linebreak_filter (head, groupcode)
>    for t in node.traverse(head) do
>       if is_cjk_ideo (t) then
>      texio.write_nl ('*** CJK Ideo ***')
>       elseif is_cjk_puncts (t) then
>      texio.write_nl ('*** CJK Punct ***')
>      for k in pairs(font.fonts[t.font]) do
>         texio.write_nl (k)
>      end
>       end
>    end
>    return true
> end
> 
> With "fontdata.cache = 'no'", I just got:

as we cache fonts at the lua end we don't want interference at the tex 
end (not duplicate table creation); the no tells luatex not to manage a 
cache at the tex end (i.e. no free not creation)

the "no" tells luatex not to keep a reference to the table it gets 
passed and when you then use font.fonts it will recreate a table from 
the data at the tex end and descriptions (and of course all other extra 
that i create and manage at the lua end is not available)

at the lua end you can use fonts.ids[id] instead and then you will get a 
descriptions (and leave the fontdata.cache key untouched unless you want 
to waste memory and runtime)

Hans

ps. i will look into this bbox based compensation once we have a proper 
set of guaranteed correct standard cjk fonts in tex live and i've 
figured out a robust way to deal with it; i had code for it but threw it 
away out when i ran into conflicts with opentype features that do 
similar things and fonts that were inconsistent

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                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
      tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
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