[pdftex] pdftex line-drawing specials

[Avery Andrews]

Hello,

I've presently got some postscript specials (for dvips) for drawing
lines and arrows for linguistics diagrams (originally by Emma Pease, with some
enhancements by me), and from what little I've learned about the pdf
format it seems like it might not be too difficult to produce a pdf
version of these for use with pdftex; it would be very helpful if
somebody could point me gently in the right direction for how to do
this, at least two things I think I need to know being:

 a) how to put a pdf special into a latex document, similarly to a
    postscript special

 b) a manual of pdf commands.

I've guessed that replacing \special{ps: with \special{pdf: would be
the answer to (a), and that seems to work but then the actual specials
crash because acrobat doesn't like the `@beginspec' commands that these
specials start with.

It's been a long time since I've seriously messed with this kind of
thing, so I've likely forgotten important stuff.

 Thanks
  Avery.Andrews at anu.edu.au