sshirokov/csgtool — pull request #10 by sshirokov (2013-06-03 20:15:41+00:00)
Title: bsp_invert()

This is work to implement `bsp_invert()` in preparation, and based on the foundation of `poly_invert()` from #9

### A play in several acts

* [x] Poly invert #9
* [x] Test for bsp_invert()
* [ ] Invert current node
* [ ] Invert front/back trees
* [ ] Flip `node.front` <=> `node.back`