【QGIS跨平台编译】之【geos跨平台编译】：源码及跨平台编译工程（支撑QGIS跨平台编译，以及二次研发）

GEOS -- Geometry Engine, Open Source ==================================== GEOS is a C++ 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://libgeos.org). The official Git repository is at [GitHub](https://github.com/libgeos/geos). ## Build Status | CI | Status | CI | Status | CI | Status | | :---: | :----- | :---: | :----- | :---: | :----- | | GitHub | [](https://github.com/libgeos/geos/actions?query=workflow:CI+branch:main) | Bessie | [](https://debbie.postgis.net/view/GEOS/job/GEOS_Worker_Run/label=bessie) | Debbie | [](https://debbie.postgis.net/view/GEOS/job/GEOS_Master/) | | Azure | [](https://dev.azure.com/libgeos/geos/_build/latest?definitionId=2&branchName=main) | Bessie32 | [](https://debbie.postgis.net/view/GEOS/job/GEOS_Worker_Run/label=bessie32) | Winnie | [](https://winnie.postgis.net/view/GEOS/job/GEOS_Master/) | | GitLab CI | [](https://gitlab.com/geos/libgeos/commits/main) | Berrie | [](https://debbie.postgis.net/view/GEOS/job/GEOS_Worker_Run/label=berrie) | Dronie | [](https://dronie.osgeo.org/geos/geos?branch=master) | | AppVeyor | [](https://ci.appveyor.com/project/dbaston/geos/branch/main) | Berrie64 | [](https://debbie.postgis.net/view/GEOS/job/GEOS_Worker_Run/label=berrie64) | ## Community Resources * Website: https://libgeos.org * **git** repository: https://github.com/libgeos/geos * [**geos-devel** mailing list](https://lists.osgeo.org/mailman/listinfo/geos-devel) and [archive](https://lists.osgeo.org/pipermail/geos-devel/) * **#geos** chat channel (all bridged): * Matrix: https://matrix.to/#/#geos:osgeo.org * IRC: irc://irc.libera.chat/#osgeo-geos (https://kiwiirc.com/nextclient/irc.libera.chat/#osgeo-geos) * Slack: https://osgeo.slack.com/messages/C07RKJ06B/ ## Build/Install See the [INSTALL](INSTALL.md) file. ## Reference Docs * [C API](https://libgeos.org/doxygen/geos__c_8h.html) * [C++ API](https://libgeos.org/doxygen/cpp_iface.html) See also the [C API tutorial](https://libgeos.org/usage/c_api/) and the [C++ API tutorial](https://libgeos.org/usage/cpp_api/). There are code [examples](https://github.com/libgeos/geos/tree/main/examples) in the code repository. ## 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> C++ usage examples can be found in `doc/example.cpp`. ### Scripting Language Bindings #### Ruby Ruby bindings are available via [RGeo](https://github.com/rgeo/rgeo). #### 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) 2. [PyGEOS](https://github.com/pygeos/pygeos) 3. Calling functions from `libgeos_c` via Python ctypes ## Documentation API documentation can be generated using Doxygen. Documentation is not included in the default build. To build the documentation, run: cmake -DBUILD_DOCUMENTATION=YES cmake --build . --target docs ## Style To format your code into the desired style, use the astyle version included in source tree: tools/astyle.sh <yourfile.cpp> ## Testing See documentation [here](tests/README.md). ## Tools * `geosop` - a CLI for GEOS. Documentation is [here](util/geosop/README.md).