[pdftex] pdfpages & font factorization

[Jean-Christophe Dubacq]

On Sat, Jun 26, 2004 at 02:31:53PM +0700, The Thanh Han wrote:
> if you have the corresponding entries for the fonts used in those
> pictures in your map files (pdftex.map) and the fonts themselves, then
> pdftex will embed them only once (and subsettted).

Since the figures were generated by a completely different system, how
does it recognize the fonts? The font used is a postscript (type1) with
more than 256 chars (and about 20 reencoding vectors) in the figures.
I presume pdftex could sort of find the same signature in all the "font
programs" (adobe vocabulary), but how can it find a correspondance with
an existing one it its map files? Using fontids?