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About this library
What is this library
Only generates assemblies and binds everything into one package.
Provides easy access to GDAL by installing only core and runtime package
DOES NOT require installation of GDAL. From 3.7.0 version GDAL_DATA is also shipped. While it contains the proj.db database you may require proj-data grid shifts.
What is not
Does not compile all drivers. Only configured, they are listed below. By default GDAL has a lot of internal drivers.
Does not change GDAL source code.
Does not extend GDAL methods.
How to use
Universal package
Install universal package - MaxRev.Gdal.Universal. It references all runtime packages and the core package. They will be automatically installed during restore. Note that this may increase the size of your nuget cache.
Install libraries for your runtime. You can install one of them or all with no conflicts.
There is no requirement to install all of them or GDAL binaries. If you work on Windows and Linux you can skip MacOS package and vice versa.
# windows supported only for x64
dotnet add package MaxRev.Gdal.WindowsRuntime.Minimal
# install linux bundle which references both arm64 and x64 binaries
dotnet add package MaxRev.Gdal.LinuxRuntime.Minimal
# or install a specific runtime
dotnet add package MaxRev.Gdal.LinuxRuntime.Minimal.arm64
dotnet add package MaxRev.Gdal.LinuxRuntime.Minimal.x64
# install macos bundle which references both arm64 and x64 binaries
dotnet add package MaxRev.Gdal.MacosRuntime.Minimal
# or install a specific runtime
dotnet add package MaxRev.Gdal.MacosRuntime.Minimal.arm64
dotnet add package MaxRev.Gdal.MacosRuntime.Minimal.x64
Initialize libraries in runtime
using MaxRev.Gdal.Core;
// call it once, before using GDAL
// this will initialize all GDAL drivers and set PROJ6 shared library paths
GdalBase.ConfigureAll();
Profit! Use it in ordinary flow. See the section below for more info.
CLI Tools packages
The CLI packages provide GDAL command-line utilities (gdalinfo, ogr2ogr, gdal_translate, etc.) that can be invoked from your .NET application. Each CLI package automatically references the corresponding runtime package. You don't have to install the runtime package separately if you are using the CLI package - it includes a package reference to the runtime nugets.
Install the CLI package for your target platform along with the runtime:
Use the GdalCli helper class (automatically included via the package):
using MaxRev.Gdal.CLI;
// GdalCli.Run calls EnsureEnvironment() automatically on module load.
// OPTIONAL - You can also call it explicitly if needed:
// GdalCli.EnsureEnvironment();
// Run a GDAL tool and capture output
var exitCode = GdalCli.Run("gdalinfo", new[] { "--version" },
stdout: Console.Write,
stderr: Console.Error.Write);
// Run with file arguments
var result = GdalCli.Run("ogr2ogr",
new[] { "-f", "GeoJSON", "output.geojson", "input.shp" });
// Get the path to a GDAL tool
var toolPath = GdalCli.GetToolPath("gdalinfo");
The CLI package includes two source files (GdalCli helper and PathInitializer) that are compiled directly into your project via buildTransitive targets. There is no extra assembly dependency - these become part of your application.
On startup, a [ModuleInitializer] automatically configures the process environment so the native GDAL tools can locate their shared libraries:
Windows: prepends the native runtime directory to PATH
Linux: prepends to LD_LIBRARY_PATH
macOS: prepends to DYLD_LIBRARY_PATH
All platforms: sets GDAL_DATA and PROJ_LIB to the bundled data directories
When you call GdalCli.Run(...), it spawns the tool as a child process which inherits these environment variables. The initialization is idempotent - GdalCli.EnsureEnvironment() can be called explicitly but will only run once.
You can disable the automatic source inclusion by setting MaxRevGdalCliEnablePathInitializer to false in your project file if you want to manage environment setup yourself.
Supported runtimes
Windows x64 (.NET Framework 4.6.1+, .NET Standard 2.0+, .NET 6/7/8+)
Linux x64/arm64 (.NET Framework 4.6.1+, .NET Standard 2.0+, .NET 6/7/8+)
MacOS x64/arm64 (.NET Framework 4.6.1+, .NET Standard 2.0+, .NET 6/7/8+)
This means you can build .NET Framework applications on Linux/MacOS using Mono.
Also, any project based on NET Standard 2.0 or higher can utilize this library.
Using GDAL functions
If you're struggling using GDAL functions.
Here's a good place to start:
The package configuration is marked as minimal. That means you don't have to install GDAL binaries. Also, some uncommon drivers are not available (were not built).
Drivers included PROJ, GEOS, and more than 200 other drivers.
NOTE: Runtime drivers availability may differ. Ask me about a specific driver for runtime. Please issue if I need to mention any packages.
Starting version 3.9.0 the packages can be compiled and run on .NET Framework 4.6.1+. The libraries and gdal-data will be automatically copied to the output directory. See tests/MaxRev.Gdal.Core.Tests.NetFramework for more info.
Building runtime libraries
Each runtime has to be build separately, but this can be done concurrently as they are using different contexts (build folders). Primary operating bindings (in gdal.core package) are build from windows. Still, the resulting core bindings are the same on each runtime package (OS).
To make everything work smoothly, each configuration targets the same drivers and their versions, respectively.
To start building for a specific runtime, see the README.md in a respective directory.
FAQ
Q: Packages does not work on CentOS 7, Ubuntu 18.04
A: These are old distros and are out of support (EOL). Use docker (see this Dockerfile how to package your app) or a newer distro (GLIBC 2.31+). Packages for older systems are difficult to maintain. From 3.6.x version the Debian 11 distro is used. See this for more info.
Q: Can I compile it on Ubuntu or another Unix-based system?
A: Yes, you can (see unix folder for readme). All you have to do, is to choose one of the latest distros like Ubuntu 22.04 or Debian 11 (recommended). From the 3.6.x version the Debian 11 distro is used by default. It was changed because of EOL of the previous distro (see answer above). Prior to 3.6.x version packages were built on CentOS - glibc of version 2.17. It's the lowest version (in my opinion) that suits all common systems (Ubuntu, Debian, Fedora).
Q: Projections are not working as expected
A: This package only contains the proj.db database. Make sure you have installed proj-data package. It contains aditional grid shifts and other data required for projections. Add path to your data folder with MaxRev.Gdal.Core.Proj.Configure(). See this for more info.
Q: Some drivers complain about missing data files
A: This is related to the previous package versions (prior to 3.7.0). From 3.7.0 version, GDAL_DATA folder is also shipped with core package.
Q: Missing {some} drivers, can you add more?
A: Feel free to contribute and I will help you you to add them. Here's the my additional answer.
Q: GDAL functions are not working as expected
A: Try to search an issue on github. In 98% of cases, they are working fine.
Q: Some types throw exceptions from SWIG on Windows
A: Yes, currently there are some redundant types in OGR namespace. This will be fixed in the next builds.
Q: In some methods performance is slower on Unix
A: Apparently, it's not a fault of the build engine. I did not face this issue and I use this packages in several production environments.
A: That's a problem with swig bindings. Please, use SpatialReference type from OSR namespace. More info here and here.
Q: Packages does not work on MacOS Catalina or lower
A: The current version of packages was compiled on MacOS Ventura and 11.3 SDK respectively. Consider updating your system to at least MacOS 13. The systems that reached EOL (end-of-life) won't be supported.
Q: The first run on MacOS is slow and takes more than 3 seconds
A: It's a known issue related to the linking of the shared libraries. If you find any solution/workaround, please let me know.
Currently, linker tries to find all shared libraries in the @loader_path/. It should point to the executable directory.
Q: BadImageFormatException on Windows
A: Ensure that you are using the same architecture for your project and the runtime package. If you are using AnyCPU, you should use only the x64 runtime package. See the sample project for details in tests/MaxRev.Gdal.Core.Tests.NetFramework.
Q: macOS shows an error Apple couldn't verify xxx.dylib
A: The packages were not signed during build in CI. Why? Because it requires to have a paid developer account which does not fall under this repo maintenance. For the workarounds see osx/README.md.
Q: Publishing the project with runtime packages
A: There are several ways to publish. One important thing to keep in mind, that you have to ensure the output folder contains either runtimes/<os>-<arch>/native path, gdal-data folder and maxrev.gdal.core.libshared/proj.db. In most cases this should be handled automatically by dotnet. Usually, we release a runtime-dependent binary. The end user will have to install the .NET runtime, but the size of the app will be small and the build time is faster. Otherwise, you can publish a self-contained app which will include all required .NET runtime libraries. More details on publishing can be found here. Also, see the sample dockerized project for details in tests/MaxRev.Gdal.Core.Tests/Dockerfile.
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