---

Indirect Predicates for Geometric Constructions

by Marco Attene

Consiglio Nazionale delle Ricerche
Istituto di Matematica Applicata e Tecnologie Informatiche
Sezione di Genova
IMATI-GE / CNR

This software implements fast and guaranteed floating point geometric predicates, including novel indirect predicates as described in the following article:

M. Attene. Indirect Predicates for Geometric Constructions. In Elsevier Computer-Aided Design (2020, https://doi.org/10.1016/j.cad.2020.102856).

---

Citation policy

You are free to use this software according to the licensing terms specified at the end of this document. If you use it for research purposes and produce publications, please cite the following paper that describes the underlying theory:

M. Attene. Indirect Predicates for Geometric Constructions. In Elsevier Computer-Aided Design (2020).

---

System Requirements

The software has been tested on 64 bit PCs running:

• Microsoft Windows OS with MSVC
• Linux with standard gcc/g++ development environment
• Mac OSX with CLANG.

---

Compile a test

1. Open a command prompt
2. Enter the directory containing this README file
3. cmake -S . -B build/ -D CMAKE_BUILD_TYPE=Release
4. cmake --build build/ --config Release

You may want to set the target architecture to make the compiler optimize the code for your hardware. To do that, edit the CMakeLists.txt file accordingly before running the commands hereabove. By default, CMakeLists is configured for x86-64 architectures with AVX2 support.

---

Generic usage

The repository provides a header-only C++ library. To use in your code:

1. Add the "Indirect_Predicates-master/include" path to the list of paths where your compiler searches header files
2. Include "implicit_point.h" in your code
3. ALWAYS tell your compiler to use the following directives: MSVC: /fp:strict /Oi /D _CRT_SECURE_NO_WARNINGS GCC/G++/CLANG: -frounding-math -O2
4. Tell your compiler whether your CPU supports SSE2/AVX2/ARMNEON instructions MSVC: /arch:SSE2 or /arch:AVX2 or /arch:ARMV8.0 GCC/G++/CLANG: -msse2 or (-mavx2 and -mfma) or -march=armv8-a+simd

On ARM CPUs supporting NEON instructions you may need to download SIMDE from: https://github.com/simd-everywhere/simde/archive/refs/heads/master.zip

As an example, check the CMakeLists.txt provided to compile the test.cpp code. CMake automatically downloads SIMDE if necessary.

---

Copyright and license

Indirect_Predicates Authors: Marco Attene

Copyright(C) 2019: IMATI-GE / CNR

IMATI-GE / CNR is Consiglio Nazionale delle Ricerche
Istituto di Matematica Applicata e Tecnologie Informatiche
Genova (Italy)

Indirect_Predicates is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

Indirect_Predicates is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with the Indirect_Predicates. If not, see http://www.gnu.org/licenses/.