Just simple CPU calculations. I'm basically just mapping my points from 3D space to my 2D screen and drawing lines between them. Not sure if rendering engine is actually the correct term for what I am doing. The word engine kind of implies a larger scope than I am going for.

Of course, I had to massively complicate this for myself by setting out to use this for displaying basic wireframe graphics on embedded systems... Basically I currently need to figure out how to reduce my triangle based objects to ones that only have the silhouette lines or that only show triangles which are actually visible, except my line drawing setup does not allow for partially obscured faces as is.