hiya, first post
am just gonna dump the readme for a ugen i made in here cos that’s basically my question
is there a better solution than this? it is fucking gnarly tho
I’ve been using it for 4+ years now, works alright. i occaisonally have to offset for supernova when i rebuild sc
(sorry about the formatting)
begin readme
Scenario:
a bunch of synths that have been made by a sequencer - ie. with latency - are sitting in the server command queue waiting to happen
some change happens to the synthdef that means the arglists in the s_new commands for the synths in the queue are now completely invalid,
and/or buffers those synths were using have been freed,
so we really should NOT be creating those synths.
Proposal:
‘cancel’ all pending synths, that are in the command queue ie. dispatched with latency
so that the synth will start, but NO UGENS in it will be ran - not even the constructors.
To do this we do something pretty hairy.
also stop all live synths within one block (same as usual free)
use a scheme of comparing value on bus, to value passed to Synth Control
this way we don't need to keep track of synths, in order to be able be able to immediately hard-stop all of them
Approach:
scsynth
unit->mParent ( a Graph)
mCalcUnits
mNumCalcUnits
supernova needs different approach
the pointer to units list in mParent is not used - supernova attaches the stuff that it uses on top of these structs, and leaves them uninitialised
use fixed offsets into this extra attached stuff
we replace the unitdef for all units in the synth, with our own unitdef
so that all other ctors will run our ctor function
we test to see if all the unitdefs have already been replaced, to know when we are running in the context of another UGen
assumptions:
for supernova: location of units and calc_units_count
that the unitdef struct for each unit is NOT THEN USED for anything other than running the dtor
because each unit will be constructed with one unitdef (the usual one),
then destructed with another (the replacment one, from our UGen)
I think: it should be OK to have this as not the very first UGen - as long as none of the ones before require dtor functions
Should only be a good reason for it.
With intended usage, In.kr will be the only UGen before SynthStopper.
What would be alternative, more standard approach?
To cancel pending synths, the only thing I can think of is deleting the synthdef from the server
(which is synchronous, so should work)
(but will produce ‘synthdef not found’ messages, and also require a version number appended to the synthdef name,
AND also - most cumbersomely - require resending the synthdef with a new version number -
so either rebuilding it, or keeping it hanging around.)
then also employing what we do here (compare bus value with value in synth args, and free self if they don’t match)
in order to stop already-running synths.
Further:
Possibly try to work out why scsynth ignores NodeEnd() done in ctor - it differs from supernova, here.
LATER if at all: run for certain number of blocks, to allow pending parameter sets to be done, before ending.
end readme