[PD] Array that scrolls from right to left

Frank Barknecht fbar at footils.org
Mon Feb 23 23:02:26 CET 2009


Hallo,
Sebastien Lelong hat gesagt: // Sebastien Lelong wrote:

> Thanks for your help. I'm getting things that "kind of" scroll... building
> an horrible patch :) Some values are random, I guess I have a problem when
> access extremities of the array. I'm sure there's something simpler,
> probably using trigger, but I can't figure out how I could use a trigger
> here. Could you give one last hint ? I guess I need to learn how to "think"
> pure data...

Indeed: Understanding triggering and execution order brings you much
closer to "thinking in Pd". There are only two things to remember: The
left inlet of (most) objects is hot, the right is cold and lets you
use an object as a storage container.

OTOH the right outlet of (most) objects fires before the left one.
This holds especially true for the [trigger] object whose main purpose
is to control the order in that your patch cords get activated. 

Both facts are nicely combined in the scrolling table solution in the
attached patch. The top [trigger] object shows how sometimes in Pd you
have to think far ahead: Its right outlet stores a number in a float
object below that gets used much later. 

The lower trigger object (abbreviated as [t ...]) shows another common
idiom: It's followed by crossed patch cords. You will often see this
when something is stored for a moment and the previously stored value
is used instead. 

Anyway the attachement shouldn't be to hard to folllow with its
comments, but feel free to ask any questions. "Getting it" is
important here. :)

Ciao
-- 
 Frank Barknecht            Do You RjDj.me?          _ ______footils.org__
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