This project demonstrates how to use the Clipper library to compute the "outer shell" of a polygon using the union operation once or repeatedly. See http://stackoverflow.com/q/23578760/77567 for the motivation.
The contents of the Clipper subdirectory are licensed under the Boost license, which is reproduced in the file Clipper/License.txt.
I dedicate the remainder of this project to the public domain, as described by the Creative Commons CC0 1.0 Universal Public Domain Dedication.