[NTG-context] on the fly TeX typesetting

Hi all, I'm just wondering how TeX labels in metapost pictures are generated when using mplib: if the set of pictures are all build through the library which saves loading time and hd read/writes, it would be strange to launch another TeX compiler. At the same time, if it were possible to have a set of defines (some macros, like for instance a set up of fonts) for TeX and be able to typeset, say, a vbox on the fly (that is, without having to deal with pages and so on), it would allow several application to take advantage of the typesetting capabilities of TeX. Any plan for a texlib? Olivier