Hi,
I just put up an abstraction for polyphonic scheduling of breakpoint envelopes here:
http://icem-www.folkwang-hochschule.de/~finnendahl/pd.html
Bare with me if this already exists, I haven't followed the list lately (I'd like to hear if something like that already exists, maybe in a better form). Bug reports are welcome.
From the download page:
"env-gen is a pd abstraction that schedules the breakpoints of envelopes triggered by events (lists) containing functiontable, timescale and overall amplitude sent to its inlet. Envelopes are stored as arbitrary length breakpoint lists (similar to ftables in csound for example). The scheduler assigns voices to these "breakpoint envelope generators" and the object sends out lists containing voicenumber, target value and deltatime at the appropriate times. In order to get the interpolation done between these breakpoints you can use line or line~ objects. An example patch is included. The "maphash" object, "glue" and "niagara" of the zexy library are needed for the abstraction to work."
-- Orm