This is a package for manipulating geometric shapes. Unlike many geometry libraries, S2 is primarily designed to work with spherical geometry, i.e., shapes drawn on a sphere rather than on a planar 2D map. This makes it especially suitable for working with geographic data.
If you want to learn more about the library, start by reading the overview and quick start document, then read the introduction to the basic types.
S2 documentation can be found on s2geometry.io.
- CMake
- A C++ compiler with C++17 support, such as g++ 7
- Abseil (standard library extensions)
- OpenSSL (for its bignum library)
- gflags command line flags, optional
- glog logging module, optional
- googletest testing framework (to build tests and example programs, optional)
On Ubuntu, all of these other than abseil can be installed via apt-get:
sudo apt-get install cmake libgflags-dev libgoogle-glog-dev libgtest-dev libssl-dev
Otherwise, you may need to install some from source.
Currently, Abseil must always be installed from source. See the use of
-DCMAKE_PREFIX_PATH in the build instructions below.
This is likely to change.
On macOS, use MacPorts or Homebrew. For MacPorts:
sudo port install cmake gflags google-glog openssl
Do not install gtest from MacPorts; instead download release
1.8.0, unpack,
and substitute
cmake -DGTEST_ROOT=/...absolute path to.../googletest-release-1.8.0/googletest ..
in the build instructions below.
Thorough testing has only been done on Ubuntu 14.04.3 and macOS 10.12.
You may either download the source as a ZIP archive, or clone the git repository.
Download ZIP file
cd [parent of directory where you want to put S2]
unzip [path to ZIP file]/s2geometry-master.zip
cd s2geometry-master
cd [parent of directory where you want to put S2]
git clone https://github.com/google/s2geometry.git
cd s2geometry
First, install Abseil.
It must be configured with -DCMAKE_POSITION_INDEPENDENT_CODE=ON.
From the appropriate directory depending on how you got the source:
mkdir build
cd build
# You can omit -DGTEST_ROOT to skip tests; see above for macOS.
cmake -DGTEST_ROOT=/usr/src/gtest -DCMAKE_PREFIX_PATH=/path/to/absl/install ..
make -j $(nproc)
make test ARGS="-j$(nproc)" # If GTEST_ROOT specified above.
sudo make install
On macOS, sysctl -n hw.logicalcpu is the equivalent of nproc.
Enable gflags and glog with cmake -DWITH_GFLAGS=ON -DWITH_GLOG=ON ....
Disable building of shared libraries with -DBUILD_SHARED_LIBS=OFF.
Enable the python interface with -DWITH_PYTHON=ON.
From build subdirectory:
make install
Prefix it with sudo if needed:
sudo make install
NOTE: There is not uninstall target but install_manifest.txt may be helpfull.
All files will be installed at location specified in CMAKE_INSTALL_PREFIX variable.
Several suffix variables used for some file groups:
| Variable | Default | Description |
|---|---|---|
CMAKE_INSTALL_INCLUDEDIR |
include |
For header files |
CMAKE_INSTALL_BINDIR |
bin |
For executables and *.dll files on DLL-based platforms |
CMAKE_INSTALL_LIBDIR |
lib |
For library files (*.so, *.a, *.lib etc) |
If needed set this variables on command line as cmake arguments with -D prefix or edit from build subdirectory:
make edit_cache
For more info read: The CMake Cache.
If you want the Python interface, you need to run cmake using
-DWITH_PYTHON=ON. You will also need to install the following dependencies:
- SWIG 4 (for Python support, optional)
- python3-dev (for Python support, optional)
which can be installed via
sudo apt-get install swig python3-dev
or on macOS:
sudo port install swig
Version 4.0 is required, but it should be easy to make it work 3.0 or probably even 2.0.
Python 3 is required.
- Go (Approximately 40% complete.)
- Java (Some newer C++ features are missing; last updated in 2021.)
- Kotlin (Complete except binary serialization)
This is not an official Google product.