Hi,
I try to understand how this macro by testing a simple example. Why pdf file
is empty ?
This question follows my question Cover page (Metafun)
http://www.ntg.nl/pipermail/ntg-context/2015/083078.html
Thank you.

\setuppagenumbering[location=]

\setupcolors
  [state=start]

\setMPtext{text}{MATHEMATIQUES}


\starttext
\startuseMPgraphic{test}
picture pic ;
pic := image(graphictext \MPstring{text}
withdrawcolor red
withpen pencircle scaled 1pt ; ) ;
addto currentpicture also pic ;
\stopuseMPgraphic
\stoptext