Hey there, this is an old project of mine. I implemented the Xiaolin Wu circle algorithm to get somewhat nice circles out of data structures. Only somewhat, because the color resolution of data structures is very limited, it has only eight values for every RGB color. So when the foreground and the background are very far away color-wise, like black and white, the algorithm gets a somewhat good result. Not perfect as in the original algorithm, as the color values still have to be rounded to the nearest data structure color. But it is alright. If background and foreground are very close, there is not very much room for interpolation and the result gets worse. Anyhow, this is the patch: circle20.pd

I am not sure if this is already finished, as the patch is almost two years old. I remember having a hard time calculating the number of actual dots to draw the circle. I hope that the amount is accurate in this version

So the whole project was actually to create nice vanilla knobs. So here is the next step in the project: circle2.zip

This time, not only one circle is created, but two circles overlapping each other. And instead of drawing only the dots, a data structure line is created to fill the space in between. This is already optimized in many ways. So for example, the algorithm only runs for one quarter and the other three quarters are mirrored (If i recall correctly, this is a long time and i haven't reviewed the code again, just posting the patches). Anyhow it is already beginning to get heavy, as you can see when redrawing the circle. So a project with such knobs would also get heavy very quickly, but this depends on the number and size of the knobs.

This version already includes a version of xy, but i am not sure what version

The whole project came to a hold when i realized that it is not possible to get rid of the border with the current version of xy, as xy uses graphical arrays that hide at the top and bottom border line. To get rid of the borders, i invented colarray, where the arrays of xy could just have the color of the background or even better yet, could have line width zero, which makes them actually invisible. But i ran into some TCL errors that couldn't be resolved, when i just tried to include colarray into xy. So the next step would have been to incorporate the colarray code into xy and make a new version of xy that would have no borders and could therefor be completely invisible. But then i ran out of steem as the project went quite complex. Anyhow, this is the project so far, have fun

@ingox amazing, I'm very impressed.
Thank you!