Hi all, Yann, thanks for giving some thought to this. Indeed, your notes are pretty incomprehensible to me, though I do like how you write the date :)
I don't have anything to add to Till's explanation of demand ugens in SuperCollider, except to note that updating/requesting a new value from a process with a trigger seems easier to implement in faust than resetting its internal state (which seems quite non-functional). I have been working on this and I have come up with some faust code which I think implements correctly a couple of demand rate functions in existing faust semantics (using ~, not control). It's quite hacky but it does seem to work. I'm a bit busy at the moment so not sure when I'll get a chance to finish it and write it up to the list - possibly some time this week, possibly next. Hope that helps, James On 8/5/20, Till Bovermann <lf...@lfsaw.de> wrote: > Dear Yann, > > > I can try... > > In SC, a demand-rate UGen graph is encapsuled into one of (currently) three > different UGens: > > Demand.ar/kr > Duty.ar/kr > TDuty.ar/kr > > Their functionality vary marginally (triggered execution/execution every > `dur` secs, etc.). > > Each of them has three slots: > > 1. update input — either a trigger (Demand) or a Demand-rate UGen / scalar > (duration, Duty/TDuty) > 2. reset input — if value passes from neg to pos, reset the value stream to > initial conditions > 3. value stream — a Demand-rate UGen graph > > > Demand-rate UGens are UGens that calculate their values every time they are > triggered to do so from the outside, read more elaborate descriptions on > this here: > > http://doc.sccode.org/Classes/Demand.html > and > http://doc.sccode.org/Classes/Duty.html > > > internally, the wrapper-UGens (Demand et al) implement the following > behavior: > > ``` > if reset: > call `next(nan)` on Demand-UGen in demand chain, this makes it reset. > else if call for next value: > calculate how many values are needed for the current block (N) > ask for N values from demand chain by providing > else: > keep last value (Demand/Duty), or 0 (TDemand) > ``` > > > A demand-rate UGen with parameters in its param-slots does this if its next > function is called: > > ``` > if numSamples == nan: > for each UGen in param-slots: > call `next(nan)`, this makes it reset. > reset myself > else: > for each UGen in param-slots: > call next(numSamples) and collect values in array > compute numSample output based on parameters > ``` > > All relevant source code for the implementation is here: > > https://github.com/supercollider/supercollider/blob/develop/server/plugins/DemandUGens.cpp > > > hope this helps and I did not make too many errors... > Till > > -- > Till Bovermann > > https://tai-studio.org | http://lfsaw.de | > https://www.instagram.com/_lfsaw/ _______________________________________________ Faudiostream-users mailing list Faudiostream-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/faudiostream-users
