I came across this shape/logo in another forum.
I thought it was a fun challenge, hopefully people come up with more challenges to share in this thread.
Here's the shape,

Now try to reproduce it in GIMP... I hope you have fun.
The idea is try to reproduce it so it has the same look and feel, different size is okay.

nice offnuts.
After a while once other people have a shot at it, you should share how you did yours to get the circles so smooth and perfect.
I used circle selection and turned it to path and i guess it has artifacts.

I downloaded the xcf...and still don't know what you did to get it hehe I got lots to learn

Rather easy:

1) position two guides to check the centering
2) along the vertical guide, make a vertical path with one anchor at the center, and one anchor in the middle of each arc ("Unnamed")
3) use my path-to-shape script to get the corresponding circle paths (the other path)
4) add 3 horizontal guides, positioned on the center of the circular end of each arc
5) with the path editor, cut the circles (add two points on the guide, and remove the arc in between)
6) measure the arc widths (20px) and sample the foreground color
7) Edit>Stroke path, Line mode, 20px, round caps.

Looks like a quarter, half, and 3/4 circle. As to calculating the starting points, I wouldn't approach it that way. I would create 3 concentric circles and cut off each as needed

Not missing much to become a Wifi Icon:

OK; harder then I thought. The rounded ends is what makes my original ideal tough. Instead of that, I created 3 circular paths (Shape Path>Circle Script-fu) and then used ofnut's unclose to start things off. The big circle and small circle were easy; big circle was done; small circle just needed to delete two path points. The middle circle, I added two points (eyeballed; can be done more accurately if I would have used a guide) and then deleted two points.

I thought that shape looked familiar to me, but I just couldn't place it.
I used basically the same method as did you Ofnuts. I added a second black layer, 1 pixel larger beneath my purple layer.

this was a good opportunity to use edit paths (which i didn't know that you can add points to an existing path, and delete parts of paths before, that makes it much more powerful).
and i downloaded the path to shape plug in (great).
and guides, never used guides before this.

had to practice guides and paths.

original image:


I just noticed that it's got different widths for each arc, so I used the original as a reference just enlarged it and did this


it's weird a circular selection turned into a path still produces some artifacts.

Back to my original idea this time. After stroking all 3 circles and clipping them. I flattened, blurred and then level adjusted to get the ends right.

This also used the original as reference but I used offnuts circles (it creates perfect circles paths and doesn't produce artifacts like if you selected a circle and then changed it to a path)

The rounded ends i thought was easy before using pure paths, i created 3 circles (by selecting circles then turned them into paths) cut off what didn't want and then set the brush to be same size as stroke (round brush) and just dotted the ends (the brush draws a circle of as you hover so it's easy to aim at the end points.

I just thought of a better way using my original idea tran. Just use the selecition mask and a paint brush to create the end nobs. Done.

Well; not so good. lol

you can just go in and dot the end points with a proper sized brush now



but as you can see my dots aren't perfect, it'd be easier to perfect the dotting if the end were cut so that they were pendicular to the tangent at the point.

with the below i cut of the ends to have a cut perpendicular to the tangent of each end point then dotted it.

Your result's definitely better then my lazy guy's attempt Tran. lol

I wonder why you are going into so much trouble for the end points since the round caps in "Stroke path" are doing the job?

Just easier to create circles then curved lines where you need to precisely define beginning and end points ofnuts.