Computational Geometry
Books
This is an incomplete list. If you use any of these books to help you solve homework problems, don't forget to cite them, just like you would any other source. Authors labeled 
were faculty at Illinois when their books were published.
- Jean-Daniel Boissonnat and Mariette Yvinec,
Algorithmic Geometry, Cambridge Univ. Press, 1998.
Translated from French by Hervé Brönnimann.
- Satyan L. Devadoss and Joseph O'Rourke,
Discrete and Computational Geometry, Princeton Univ. Press, 2011.
- Herbert Edelsbrunner,
Algorithms in Combinatorial Geometry, Springer, 1987.
PDF version available through
the university's library proxy.
- Jacob E. Goodman, Joseph O'Rourke, and Csaba D. Tóth (editors),
Handbook of Discrete and Computational Geometry,
3rd edition, CRC Press, 2017. Individual chapters available as PDF files.
- Sariel Har-Peled,
Geometric Approximation Algorithms,
AMS Press, 2011.
Early draft and additional material available as PDF files.
- Jiří Matoušek,
Lectures on Discrete Geometry, Springer, 2002.
PDF version available through
the university's library proxy.
- Joseph O'Rourke,
Computational Geometry in C,
Second Edition, Cambridge Univ. Press, 1998.
- Franco P. Preparata and Michael Ian Shamos,
Computational Geometry: An Introduction, Springer, 1985.
PDF version available through
the university's library proxy.
Online resources
Again, this is an incomplete list. I'm deliberately omitting lots of useful Java applets, because Java applets are dead. I'm also deliberately omitting thousands of other github repositories, because I just don't have time to review/filter them all. I'll add more resources as I discover them.