I would like to make a Knob GUI in GEM.

in order to do so, I want to draw arc of a donut shape.

Any suggestions?

Sorry, I don't really understand. Arc of a donut shape?

You're able to control the width of shapes in GEM using a message box and number atom going into the hot inlet, like so:

[3\
|
[width $1(
|
[circle]

Unfortunately, because of how the circle is drawn in PD, you tend to end up with corners on the outer edge of your ring. Push it hard enough on a small circle, you get a plus sign, which is a neat "Feature." I'm sure there's a way around this, which will most likely be clunky as Hell, possibly using [curve].

OK, I think I get what you mean, now. Basically, you want a ring with a thickness of whatever. You click and can rotate the object like you would [knob] or something.

Here's a really sketchy and buggy thing to maybe get you started. The [gemmouse] uses input from your mouse. [spigot] kind of turns the object on when you left click, then you move your mouse up or down to rotate one element. This is mostly an illusion of a knob GUI control, and definitely needs A LOT of work to make it functional.

http://www.pdpatchrepo.info/hurleur/crapGUI.pd

Hello What?,

I think he means something like on the picture.

That would be really cool if that would work in GEM without texture-layers.

greetings from Kandy

http://www.pdpatchrepo.info/hurleur/knob.scala.png

Hi, kandy!
Your image looks like exactly what I meant.
I don't care if it requires texture-layers to do it.
Just let me know how to draw arc of a ring shape.

This is only created with photoshop