On Thu, Jan 16, 2020 at 1:03 PM Christof Ressi <[email protected]> wrote: > > it's certainly not a good idea to (possibly) modify the DSP graph while it's > being built.
Or a *great* idea >As I said, the external should use a clock to schedule the message for the >next tick. Here's what seems possible: The canvas "dsp" method gets called on toplevel canvases. It adds all the objects in the canvas with "dsp" methods to an unsorted list. Then, in ugen_done_graph, the main work of setting up the dspcontext struct from block~/switch~ happens. It allocates all the signals, and ugen_doit puts each chain of objects in a queue to have their "dsp" methods run. Then it finally reaches a sub-patch (a canvas object), and its "dsp" method gets called. The outcome depends on which runs first--the blocksize~ "dsp" method or the sub-patch canvas "dsp" method. Sub-patch blocksizes could still be set, during graph generation, because the block~ parameters aren't even relevant until the sub-patch "dsp" method. With no signal inlets and no outlets, there's nothing there to force it to come before/after the sub-patch "dsp" method. If blocksize~ had a signal inlet, you could connect it to a subpatch output and be guaranteed that the sub-patch "dsp" method will be called before the blocksize~ "dsp" And vice versa (the interesting case): if blocksize~ has a signal outlet connected to some sub-patch inlet, then it's possible to set the sub-patch block~/switch~ parameters during the graph generation, right before they are to be used. But.... I still have questions. Will the block~ "set" method trigger the dsp graph to be rebuilt, at some point when it's already trying to build the graph? What would happen if it did? > > Gesendet: Donnerstag, 16. Januar 2020 um 19:07 Uhr > > Von: "Charles Z Henry" <[email protected]> > > An: Pd-List <[email protected]> > > Betreff: Re: [PD] Any problems else/blocksize changing subpatch blocking > > during dsp? > > > > On Thu, Jan 16, 2020 at 10:03 AM Christof Ressi <[email protected]> > > wrote: > > > > > > I also think that messaging an outlet in the "dsp" method is not a good > > > idea and it's better to use a clock with delay 0. The user might take the > > > output of [blocksize~] and accidentally do something which interferes > > > with DSP graph generation, e.g. by resizing an array, creating/deleting > > > objects, etc. > > > > > > Christof > > > > Yes it *could*, but I'm unclear on the timing. I've read and > > consulted the d_ugen.c code recently but . The block parameters are > > derived from block/switch and coded into the dspcontext struct which > > gets generated for each canvas. The parameters have to be known > > before "dsp" gets called in the current canvas (which would trigger > > the "blocksize~" output), but is the sub-patch dspcontext already > > built? I'll try to follow up later today and try to answer it > > > > That ambiguity could be resolved by looking at the "bang~" code. I > > just think it's an interesting question what is possible to happen as > > it is currently written > > > > bang~ sends properly timed messages by using: > > t_clock *x_clock; //in the data structure > > > > x->x_clock = clock_new(x, (t_method)bang_tilde_tick); // in the "new" method > > > > static void bang_tilde_tick(t_bang *x) // added "tick" method > > { outlet_bang(x->x_obj.ob_outlet); } > > > > and > > clock_delay(x->x_clock, 0); // in the "perform" routine > > > > Chuck > > > > > > > > _______________________________________________ > > [email protected] mailing list > > UNSUBSCRIBE and account-management -> > > https://lists.puredata.info/listinfo/pd-list > > _______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
