Re: fonts in embedded tex in embedded metapost in context

[Hans Hagen <pragma@wxs.nl>]

At 10:34 PM 12/8/00 +0100, Denis B. Roegel wrote:

>\starttext
>\startMPenvironment 
>\ss
>\enableencoding [il1]
>\stopMPenvironment 
>\startuseMPgraphic{test}
>label(btex élève etex,origin);
>\stopuseMPgraphic
>\useMPgraphic{test}
>\stoptext
>
>and it doesn't display ``é'' and ``è''.
>
>When I look at the mpx file, I see
>
>begingroup save _p,_r,_s,_n; picture _p; _p=nullpicture;
>string _n[];
>vardef _s(expr _t,_f,_m,_x,_y)=
>  addto _p also _t infont _f scaled _m shifted (_x,_y); enddef;
>_n0="cmss12";
>_s("lve",_n0,1.00000,0.0000,0.0000);
>setbounds _p to (0,0.0000)--(13.3110,0.0000)--
> (13.3110,8.3022)--(0,8.3022)--cycle;
>_p endgroup
>mpxbreak
>
>so presumably, the problem is cmss12.
>
>Can you explain how ``é'' is handled? In LaTeX, 
>é becomes \'e (with the input encoding latin1) and
>this is translated into some position in the font,
>or some combination of characters. With cmss12, LaTeX
>would map \'e to some \accent combination.
>
>What is the context position on this matter?

\'e is mapped onto a glyph when present, or composed, like in cmr when not

the same goes for é but here it can either be a direct mapping on a glyph
or an active character expanding into \'e and thereby mapped onto a glyph
or composed char

so anything can be the case: 

\command char => accented glyph
\command char => accent + glyph
char          => accented glyph [with same code]
active char   => accented glyph
active char   => accent + glyph

the 

\command char mapping is called an encoding
direct mapping is just direct mapping
active char mapping is called a regime 

[there is also unicode mapping with intermediate remapping as well as pdf
remapping at the output level] 

So, when you need for cmr, since there are no direct glyphs, is either \'e
or a regime that makes the il1 chars into active chars and maps them. 

You may try: 

\enableregime[win] 
\enableregime[ibm] 

or whatever matches il1, else we need to make one. [see enco-win for an
example]

A regime is enabled in the document and an encoding is either enables in
the document or assiciated with a font file name. 

Ah, and there are also special character sequences [grep for
languagespecifics] which map for instance "e onto \"e onto
glyph/accent+char. This is for instance used in germany.   

So, the machinery [and in many cases the fuel too] is there.  

Hans
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