[PD] howto gain finer resolutions of message/audio interaction?

Miller Puckette mpuckett at man104-1.ucsd.edu
Sun Aug 17 07:19:38 CEST 2003

On Sat, Aug 16, 2003 at 10:55:50PM +0200, errorsmith wrote:
> Hello,
> thank you for the quick and helpful replies.
> Maybe I am wrong but I think something is wrong with vline~.
> The triangle wave in C04.control.to.signal.pd sounds and looks corrupted.
> (see attached pd file).

Wow, you're right, except that the bug turned out to be in the Pd scheduler!
Thanks for flagging this; it was subtle and potentially ugly.  
To fix, m_sched.c, lines 358-359 should read:

    sys_time = next_sys_time;

(i.e., reverse the order of the two lines).  Then just ./configure and make
and vline~ should be as good as new... or just wait till Monday when I can
get the compiled Mac version out.  I'll probably try to get in one more
"improvement" too, to reduce audio latency a bit further.

> But I think I get the idea of the time tagged messages.
> Would vline~ also take more than 1 message per audio block? I mean would it
> be possible to generate an message stream with a periode smaller than 64
> samples and vline~ generates ramps between them? I tried it and it seems
> only one message per block is taken, I guess the latest one, but maybe
> vline~ is buggy.
You can update at periods less than a single sample, if you really want to...
the thing will (OK, _should_) be able to queue any number of updates you


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