Edge Addition Planarity Suite

The primary purpose of this repository is to provide implementations of the edge addition planar graph embedding algorithm and related algorithms, including a planar graph drawing method, an isolator for a minimal subgraph obstructing planarity in non-planar graphs, outerplanar graph embedder and obstruction isolator algorithms, and tester/isolator algorithms for subgraphs homeomorphic to K_2,3, K₄, and K_3,3. The C implementations in this repository are the reference implementations of algorithms appearing in the following papers:

As secondary purpose of this repository is to provide a generalized graph API that enables implementation of a very wide range of in-memory graph algorithms including basic methods for reading, writing, depth first search, and lowpoint as well as advanced methods for solving planarity, outerplanarity, drawing, and selected subgraph homeomorphism problems. An extension mechanism is also provided to enable implementation of planarity-related algorithms by overriding and augmenting data structures and methods of the core planarity algorithm.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes.

Pre-compiled Executable Releases for Non-Developers

On several (Debian-based) distributions of Linux, you may be able to get the planarity executable with sudo apt install planarity, or you may already have it if you have Matlab. For non-developer Windows users, there is also a pre-compiled executable version of the algorithm implementations: download and decompress the planarity-N.N.N.N.WindowsExe.zip file.

If you run the planarity executable program, it will offer an interactive, menu-driven mode that lets a user manually select algorithms to run and, where appropriate, files containing graphs on which to run the algorithms.

The planarity executable program also supports an extensive list of command-line parameters that make it possible to automate the execution of any of the algorithms included in the application. Run planarity with the -h command-line parameter to get more information about the command line options, and use -h -menu for more extensive information about command-line mode. Essentially, all functionality available in the interactive, menu-driven mode is also available via the command-line parameters.

Setting up a Development Environment

Please refer to the 2. Dev Setup wiki page for instructions on how to install development dependencies on various supported platforms, as well as how to get started working with the project in Visual Studio Code.

Making the Distribution

Once one has set up the development environment and is able to work with the code in the development environment, it is possible to make the distribution with the following additional steps:

Ensure that the autotools, configure, and make are available on the command-line (e.g. add C:\MinGW\msys\1.0\bin to the system PATH before Windows Program Files to ensure that the find program is the one from MSYS rather than the one from Windows (e.g. adjust the PATH variable as needed)).
Navigate to the root of the edge-addition-planarity-suite repository (i.e. the directory containing configure.ac and the c subdirectory)
Get into bash (e.g., type bash in the Windows command-line), then enter the following commands:
1. ./autogen.sh
2. ./configure
3. make dist
4. make distcheck

The result is a validated planarity-N.N.N.N.tar.gz distribution, where N.N.N.N is the version number expressed in the configure.ac file.

Making and Running the Software from the Distribution

If you have done the steps to set up the development environment and work with the code, then you can make and run the software using the development environment, so you don't necessarily need to make or run the software using the process below.

You also don't necessarily need to make and make install the planarity software on Linux if you are able to get it using sudo apt planarity (i.e. using a Debian-based Linux distribution, which uses apt for package management)

However, you may have only downloaded the distribution (i.e., planarity-N.N.N.N.tar.gz) from a Release tag of this project. Once you have decompressed the distribution into a directory, you can make it by getting into bash (e.g. type bash in the Windows command-line) and then entering the following commands:

./configure
make

At this point, the planarity executable can be run from within the distribution directory. For example, on Windows, go to the .libs/ subdirectory containing the planarity executuable and the libplanarity DLL and run planarity -test ../c/samples on the command-line.

On Linux, the planarity program can also be installed by entering sudo make install on the command-line. Note that the libplanarity shared object and symlinks will be installed to /usr/local/lib so it will be necessary to set LD_LIBRARY_PATH accordingly. For one session, this can be done with export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib. To make it more permanent, you could use:

Create a new file /etc/ld.so.conf.d/planarity.conf containing /usr/local/lib
Run sudo ldconfig

Versioning

The APIs for the graph library and the planarity algorithm implementations are versioned using the method documented in configure.ac.

The planarity.exe application, which provides command-line and menu-driven interfaces for the graph library and planarity algorithms, is versioned according to the Major.Minor.Maintenance.Tweak numbering system documented in the comments in planarity.c.

License

This project is licensed under a 3-clause BSD License appearing in LICENSE.TXT.

graph-algorithms/edge-addition-planarity-suite