My abandoned project on boolean operations on meshes. Code is a mess, performance is even worse. Use at own risk.
26/02/2017 Milestone update - I finally added handling convex polygons with one hole. Soon I'll write a code for more general case and also other boolean operations. Example image for boolean sum of cube and sphere (files in repository) below.
Great thanks to Jukka Jylänki, the author of MathGeoLib. I wouldn't be able to create this library if not the simplicity of his code.
Code also uses Boost Library (http://www.boost.org) and TinyObjLoader (http://github.com/syoyo/tinyobjloader/).