> I need no optimization help. But you ask exactly for this -- for help optimizing the C -- Nim interface.
You know C well, and in the Nim cache directory there is all the C code visible, so you could invest it. I don't think that even the brightest Nim devs can just guess the problem. Investigating your code is impossible as long you do not provide it, and even when you provide it, investigation is some boring task. For your pass by ref vs pass by value, Nim generally passes larger objects by ref, I think objects smaller than the size of 3 floats is passed by value. But of course there can be a hidden bug. treeform told you already that generally you can not pass Nim ref objects, as that are owned by Nim GC.
