The stackoverflow?

[chris-english]

I think, but am not certain, that you would like to take a look at RTriangle, based on Jonathan Shewcut's C implementation Triangle. Further, as you're a reader, pretty much anything Shewcut or his protoges wrote Shewcut - Berkeley including, I would add, his C code for the comments. I'm not a C programmer, only R to a point, but if I was trying to learn elegant C, I'd read his. And, of course, I could be completely wrong as to your needs.