[Xy-pic] Writing a backend

[lfourquaux at alussinan.org]

Hello!

Is there somewhere a documentation on how to write a backend for Xy-pic? If
there isn't any beyond the comments in the source files, is there someone on
this list who could give me a few hints on how to start? I tried to
understand how existing drivers are designed, but I was unable to get a
clear view of what is required.

The problem I'd like to look into¹ is writing a PDF backend. I've whished I
had one since I discovered Xy-pic, and I just discovered that Context uses a
clever idea to translate TPIC specials to PDF: it just calls METAPOST to do
the work. Something like that could probably be adapted to Xy-pic.

So, can you help me to understand what is required, and how it works?

Thanks in advance!

-- Lionel Fourquaux



(1) Unfortunately, I'll probably not do anything beyond looking into this,
since I do not have the time to develop a full-fledged backend, and I'm not
sure I have the required expertise. However, I'd be interested in trying to
start it.