[PD-dev] much better scrolling algorithm (pd-extended 0.42.5)

Ivica Ico Bukvic ico at vt.edu
Fri Dec 4 13:56:14 CET 2009

> > please see attached patch. it applies cleanly against 0.41.4
> > extended as
> > well as 0.42.5 extended.
> >
> > ico
> > <patch>
> It works for me Pd-extended 0.42.5-20091112, thanks for that.  Sorry
> for the delay, its been a busy week.  Two things I tried:
> - like the current Pd-extended scroll logic, scrolling with the wheel
> moves the patch when there are no scrollbars, except it'll scroll the
> patch contents out of the visible area and not add scrollbars.

I've not touched this part. This is simply how 0.42.5 does scrolling in
respect to the mouse wheel so I would say this part has nothing to do with
my patch...

> - resizing the window doesn't seem to track comments, I tried
> 3.audio.examples/A02.amplitude.pd, the scrollbars don't kick in until
> I cover the objects.  the comments don't seem to affect the scrollbars.

I realized this earlier last week as well. This is because I am omitting
text in manually calculating bbox to avoid redundant scrollbars which are
apparent in all other versions, particularly when using number boxes with
larger fonts. I think it would be a good idea to report your experience on
this one: namely whether you are getting the same results in this respect so
that we have this also covered as part of the algorithm's assessment. 

That said, I thought a bit about this and I think text can be added in two
different ways:

1) by creating an invisible box around them (not sure if canvas supports
this) or if there is already one identifying it in the manual bbox

2) trying to figure out what is the font scaling discrepancy and applying
that number to text (once again inside manual bbox calculation since that is
the only place you could do so on an individual basis such as this one).

Best wishes,


More information about the Pd-dev mailing list