Although the PDF documentation at this website describes some of the
algorithms in the source code at this site, the following books serve as a
better source of description. The Geometric Tools book is published by
Elsevier. The remaining books are published now by
CRC Press (Taylor & Francis Group).
Amazon says the Robust and Error-Free Geometric Computing book
should be in stock July 2, 2020. The delay is COVID-19 related.
In the book I mentioned that the Geometric Tools Library (GTL) would be
available. The pandemic has affected my schedule, so the full GTL is not
yet ready. However, I back-ported all the relevant book-related code to
the current GTEngine 4.7 (and later) distribution, and that code has been
fully unit tested. All source code references in the book to GTL apply as
well to GTEngine 4.7 (and later).