[PD] why units per pixel: -1 by default on subpatches?

Alexandre Torres Porres porres at gmail.com
Sat Apr 2 04:11:26 CEST 2022


Em sex., 1 de abr. de 2022 às 13:46, Miller Puckette <msp at ucsd.edu>
escreveu:

> Because when just making a patch the origin is conventionally top left,
> not bottom left.  So pixels count downward, and if you want "y" to increase
> as you go up, that's the opposite dorection.
>

Sure, but let me see if I get things straight. This is just meaningful for
Data Structures, right? Cause if I change this in a "regular" canvas, I
don't see any difference. But maybe I'm missing something.

Now, I can see the difference is where to consider the origin (0/0
coordinate), but I don't know what's the benefit besides maybe having a
more intuitive expectation when resizing the window, right? Perhaps one
could argue it also makes easier to know where to append objects on the
canvas, but I'm not sure about that.

Anyway, I really think it makes it very confusing for setting and
retrieving field values that represent the horizontal axis. In the Data
Structures tutorial examples, like 02.getting.data, the height of the
triangle is a negative number. This is particularly troublesome for arrays,
cause we really expect that the higher the element is, the higher its value
should be.


> Just install a mirror on your desktop and look at your screen downward
> through it, and you'll see 'y' increase upward when 'scale' is set to 1 :)
>

Not sure if that fixes everything and this can be easily fixed by setting
the "Y units per pixel" value to a positive number, like in the
07.sequencer examples, which, by the way, makes much more sense to follow
the score.

I'm now revising the Data Structures tutorial in my documentation updates
and would like to bring this discussion into attention. I have changed all
the patches so the "Y" unit is set to positive values and have better
documented how this works. But anyway, I really think it makes more sense
for a default value that we have Y units set to "1".

cheers





>
> M
>
> On Mon, Mar 28, 2022 at 10:34:37PM -0300, Alexandre Torres Porres wrote:
> > Hi, I believe this must have been discussed before... it's surely known.
> I
> > wonder why when you add a subpatch the 'scale' section has an inverted
> "-1"
> > scale for the vertical axis. This is particularly bad for display data
> > structures and needs to be corrected by hand.
> >
> > Should I open a request to change this default parameter?
> >
> > cheers
>
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