[PD] [OT] Sequencing design

[bstine at telus.net]

hey Kyle!  I'm definitely interesting in patch state saving, but what i'm
looking for is theory for the sequencing mechanism.  It's because I'm trying to
write a simple sequencer...pretty much just a piano roll.

I figure the "sequencer" is either a callback that's called every X milliseconds
or some kind of event queue with timestamps thats checked by a thread.  I tried
making a callback mechanism in java and it was awful, skipped beats all the
time.  The event queue seems to work better but I was wondering what other
people have done.  The [metro] object in PD has perfect timing, if anyone could
explain how it works I'd much appreciate it.

thanks

-brendan


Quoting Kyle Klipowicz <kyleklip at gmail.com>:

> This is a good question!  Hopefully Frank's RRadical project, in
> particular the Memento class of state saving abstractions, will make
> this easier to deal with.  Also the new [list] class of objects should
> help out with this stuff.
> 
> Unfortunately,  if you are a newbie, it can be a bit of a pain in the
> ass to install Memento/RRadical and have it work.  This will change,
> I'm guessing, once Frank updates it to Pd 0.39 standards of graph on
> parent and list.
> 
> In the meantime, you can use things like [textfile] and [qlist] to
> keep track of notes, velcities, times, and other controller messages.
> 
> Anyone with more experience want to offer some expertise?
> 
> ~Kyle
> 
> On 12/2/05, bstine at telus.net <bstine at telus.net> wrote:
> >
> >
> > Hi all
> >
> > I know this is a little off topic, but this seems like the best place to
> ask.  I
> > was wondering what the best way to implement a sequencer is.  I know that's
> a
> > big question, but I mean in the most abstract way.  I've been experimenting
> with
> > java and have tried keeping the MIDI notes in a sorted list and have a
> thread
> > that, after its started, checks the elapsed time (in 1/64th ticks) compared
> to
> > the first MIDI note's timestamp.  If the timestamp matches the current tick
> then
> > it does something with that note.  I've been sending messages to Pure Data
> and
> > tested the accuracy of the clock with the [timer] object, but sometimes
> there
> > are audible differences in the timing when trying to output notes at
> regular
> > intervals.
> >
> > I hope that paragraph was coherent...my question is what is a good way to
> > implement a sequencer (if anyone has an abstract explanation)?  I'd like to
> be
> > able to record notes on the fly, if possible.
> >
> > thanks
> >
> > -brendan
> >
> >
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