Re: fonts in embedded tex in embedded metapost in context

["Denis B. Roegel" <Denis.Roegel@loria.fr>]

`Hans Hagen' wrote

>   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]
>   

None of these two lines works on

\starttext
\startMPenvironment 
\ss
\enableencoding [il1]
\enableregime[win] 
%\enableregime[ibm] 
\stopMPenvironment 
\startuseMPgraphic{test}
label(btex élève etex,origin);
\stopuseMPgraphic
\useMPgraphic{test}
\stoptext

Presumably, the regime is similar to a mapping function
(I checked the enco* files).
What I would like to know is what regime I am supposed to use
in the following cases:

  - input in il1 and cmr10 font
  - input in il1 and ecrm1000 font
  - normal 7 bit input (such as \'e) and cmr10 font
  - normal 7 bit input (such as \'e) and ecrm1000 font

Also, \enableencoding [il1] is not clear to me. What does it do?
Does it merely make a bunch of characters active?

Denis