I can feel your anger. When I started scripting(I didn’t have any knowledge of any language) I tried P, but the rhinoscriptsyntax and rc thing confused me even more. That’s basically why I started with c#
By the way, it’s an honor for me, I found something you consider worth using a scripting component:)
Here is how it could be in C#, also I thought a plane input could be useful.
I really tried to hide it but yes, I am beyond frustrated. Happens almost every time I mess with Rhino API methods. Despite being a professional programmer (retired) with extensive experience in a vast list of programming languages, the Rhino APIs have always blocked me.
More comments in the new thread but your updated C# is the only thing that works so far! (though it always returns a CCW curve instead of both CW and CCW)
Some “pro tips” to improve it:
Internalize a World XY plane on the ‘P’ input as a default.