123 строки
4.7 KiB
Markdown
123 строки
4.7 KiB
Markdown
|
GEOS -- Geometry Engine, Open Source
|
||
|
|
====================================
|
||
|
|
|
||
|
|
GEOS is a C++11 library for performing operations on two-dimensional vector
|
||
|
|
geometries. It is primarily a port of the [JTS Topology
|
||
|
|
Suite](https://github.com/locationtech/jts) Java library. It provides many of
|
||
|
|
the algorithms used by [PostGIS](http://www.postgis.net/), the
|
||
|
|
[Shapely](https://pypi.org/project/Shapely/) package for Python, the
|
||
|
|
[sf](https://github.com/r-spatial/sf) package for R, and others.
|
||
|
|
|
||
|
|
More information is available the [project homepage](https://trac.osgeo.org/geos).
|
||
|
|
|
||
|
|
## Build status
|
||
|
|
|
||
|
|
| Branch | Debbie | Winnie | Dronie | Travis CI | GitLab CI | AppVeyor |
|
||
|
|
|:--- |:--- |:--- |:--- |:--- |:--- |:--- |
|
||
|
|
| 3.8 | [](https://debbie.postgis.net/view/GEOS/job/GEOS_Branch_3.8/) | [](https://winnie.postgis.net:444/view/GEOS/job/GEOS_Branch_3.8/) | [](https://dronie.osgeo.org/geos/geos?branch=3.8) | [](https://travis-ci.com/libgeos/geos?branch=3.8) | [](https://gitlab.com/geos/libgeos/commits/3.8) | [](https://ci.appveyor.com/project/dbaston/geos/branch/3.8) |
|
||
|
|
|
||
|
|
|
||
|
|
## Build/install
|
||
|
|
|
||
|
|
See [INSTALL](./INSTALL) file
|
||
|
|
|
||
|
|
## Client applications
|
||
|
|
|
||
|
|
### Using the C interface
|
||
|
|
|
||
|
|
GEOS promises long-term stability of the C API. In general, successive releases
|
||
|
|
of the C API may add new functions but will not remove or change existing types
|
||
|
|
or function signatures. The C library uses the C++ interface, but the C library
|
||
|
|
follows normal ABI-change-sensitive versioning, so programs that link only
|
||
|
|
against the C library should work without relinking when GEOS is upgraded. For
|
||
|
|
this reason, it is recommended to use the C API for software that is intended
|
||
|
|
to be dynamically linked to a system install of GEOS.
|
||
|
|
|
||
|
|
The `geos-config` program can be used to determine appropriate compiler and
|
||
|
|
linker flags for building against the C library:
|
||
|
|
|
||
|
|
CFLAGS += `geos-config --cflags`
|
||
|
|
LDFLAGS += `geos-config --ldflags` -lgeos_c
|
||
|
|
|
||
|
|
All functionality of the C API is available through the `geos_c.h` header file.
|
||
|
|
|
||
|
|
Documentation for the C API is provided via comments in the `geos_c.h` header
|
||
|
|
file. C API usage examples can be found in the GEOS unit tests and in the
|
||
|
|
source code of software that uses GEOS, such as PostGIS and the sf package
|
||
|
|
for R.
|
||
|
|
|
||
|
|
### Using the C++ interface
|
||
|
|
|
||
|
|
The C++ interface to GEOS provides a more natural API for C++ programs, as well
|
||
|
|
as additional functionality that has not been exposed in the C API. However,
|
||
|
|
developers who decide to use the C++ interface should be aware that GEOS does
|
||
|
|
not promise API or ABI stability of the C++ API between releases. Breaking
|
||
|
|
changes in the C++ API/ABI are not typically announced or included in the NEWS
|
||
|
|
file.
|
||
|
|
|
||
|
|
The C++ library name will change on every minor release.
|
||
|
|
|
||
|
|
The `geos-config` program can be used to determine appropriate compiler and
|
||
|
|
linker flags for building against the C++ library:
|
||
|
|
|
||
|
|
CFLAGS += `geos-config --cflags`
|
||
|
|
LDFLAGS += `geos-config --ldflags` -lgeos
|
||
|
|
|
||
|
|
A compiler warning may be issued when building against the C++ library. To
|
||
|
|
remove the compiler warning, define `USE_UNSTABLE_GEOS_CPP_API` somewhere
|
||
|
|
in the program.
|
||
|
|
|
||
|
|
Commonly-used functionality of GEOS is available in the `geos.h` header file.
|
||
|
|
Less-common functionality can be accessed by including headers for individual
|
||
|
|
classes, e.g. `#include <geos/algorithm/distance/DiscreteHausdorffDistance.h>`.
|
||
|
|
|
||
|
|
#include <geos.h>
|
||
|
|
|
||
|
|
Documentation for the C++ API is available at https://geos.osgeo.org/doxygen/,
|
||
|
|
and basic C++ usage examples can be found in `doc/example.cpp`.
|
||
|
|
|
||
|
|
|
||
|
|
### Scripting language bindings
|
||
|
|
|
||
|
|
#### Ruby
|
||
|
|
|
||
|
|
Ruby bindings are part of GEOS. To build, use the `--enable-ruby` option
|
||
|
|
when configuring:
|
||
|
|
|
||
|
|
./configure .. --enable-ruby
|
||
|
|
|
||
|
|
#### PHP
|
||
|
|
|
||
|
|
PHP bindings for GEOS are available separately from
|
||
|
|
[php-geos](https://git.osgeo.org/gitea/geos/php-geos).
|
||
|
|
|
||
|
|
#### Python
|
||
|
|
|
||
|
|
Python bindings are available via:
|
||
|
|
|
||
|
|
1. [Shapely](http://pypi.python.org/pypi/Shapely) package.
|
||
|
|
2. Calling functions from `libgeos_c` via Python ctypes.
|
||
|
|
|
||
|
|
|
||
|
|
## Documentation
|
||
|
|
|
||
|
|
Doxygen documentation can be generated using either the autotools or CMake build
|
||
|
|
systems.
|
||
|
|
|
||
|
|
### Using Autotools:
|
||
|
|
|
||
|
|
cd doc
|
||
|
|
make doxygen-html
|
||
|
|
|
||
|
|
### Using CMake:
|
||
|
|
|
||
|
|
cmake -DBUILD_DOCUMENTATION=YES
|
||
|
|
make docs
|
||
|
|
|
||
|
|
## Style
|
||
|
|
|
||
|
|
To format your code into the desired style, use the astyle
|
||
|
|
version included in source tree:
|
||
|
|
|
||
|
|
tools/astyle.sh <yourfile.cpp>
|