A while ago, I was inspired by Chrisir's post here.
I have created my own shape generator, "Vertexator", on OpenProcessing.

In addition to Chrisir's implementation, it allows you to select and modify vertices, and to copy the necessary code to the clipboard upon pressing the spacebar.
The clipboard functionality is only available with a signed jar, so you may have to give permission for it to run...

I'd like to know what you think.