Sleeving is more expensive than boring an engine block, but especially for aluminum blocks, sleeves may be better able to ...
gives formula to show if a point is inside a cylinder. It is based on finding a rotation that maps the cylinder axis onto a cartesian axis, and then calculate the distance from the axis.
I've started working a personal program to design shapes with tubing (and produce G-code for a CNC tubing cutter I'm going to build). It's been roughly 20 years since I was last in a vector geometry ...