I tried to use the function~ object as an adsr~ object to both add curves and to have a visual representation of the envelope. And it’s done!
But I have a "little" problem :
How to have the retrigger function of the adsr~ object on the function~ object?
How to restart the envelope when a second note is played before the end of the first?
To be clear, here a part of the help file of the adsr~ object :
"adsr~’s retrigger function ensures click-free operation when another note-on arrives before adsr~ is ready. When this happens, adsr~ quickly ramps to 0, allowing sound parameters to be changed, then it triggers the new envelope."