# Vcpkg and Android **The latest version of this documentation is available on [GitHub](https://github.com/Microsoft/vcpkg/tree/master/docs/users/android.md).** Android is not officially supported, and there are no official android triplets at the moment. However, some packages can compile to Android, and the situation is improving: see the list of [PR related to Android](https://github.com/Microsoft/vcpkg/pulls?q=+android+). ## Android build requirements 1. Download the [android ndk](https://developer.android.com/ndk/downloads/) 2. Set environment variable `ANDROID_NDK_HOME` to your android ndk installation. For example: ````bash export ANDROID_NDK_HOME=/home/your-account/Android/Sdk/ndk-bundle ```` Or: ````bash export ANDROID_NDK_HOME=/home/your-account/Android/android-ndk-r21b ```` 3. Install [vcpkg](https://github.com/microsoft/vcpkg) 4. Set environment variable `VCPKG_ROOT` to your vcpkg installation. ````bash export VCPKG_ROOT=/path/to/vcpkg ```` ## vcpkg triplets and their corresponding android ABI There are four different Android ABI, each of which maps to a vcpkg triplet. The following table outlines the mapping from vcpkg architectures to android architectures |VCPKG_TARGET_TRIPLET | ANDROID_ABI | |---------------------------|----------------------| |arm64-android | arm64-v8a | |arm-android | armeabi-v7a | |x64-android | x86_64 | |x86-android | x86 | ## Install libraries for Android using vcpkg Example for jsoncpp: ````bash cd $VCPKG_ROOT # specify the triplet like this ./vcpkg install jsoncpp --triplet arm-android # or like this ./vcpkg install jsoncpp:arm64-android ./vcpkg install jsoncpp:x86-android ./vcpkg install jsoncpp:x64-android ```` ### Using Vulkan SDK Vcpkg has a [`vulkan` package](https://github.com/microsoft/vcpkg/blob/master/ports/vulkan/portfile.cmake) which allows you to `find_package(Vulkan)`. To use it you have to provide `VULKAN_SDK` environment variable. ```bash export VULKAN_SDK=/usr/local ./vcpkg install vulkan ``` NDK already contains [Vulkan](https://developer.android.com/ndk/guides/graphics/getting-started) headers and `libvulkan.so` binaries for each of its architecture. To expose them to VcPkg, you can consider `export VULKAN_SDK=...` for each installation. But by placing `set(ENV{VULKAN_SDK} ...)` in the triplet files, you can skip the tedious work. If you are using NDK 21.3.6528147 or earlier version, it will be like the following. ```cmake # In android triplets... (e.g. arm64-android.cmake) set(VCPKG_CMAKE_SYSTEM_NAME Android) # ... # If your API level is 30, libvulkan.so is at $ENV{ANDROID_NDK_HOME}/platforms/android-30/arch-arm64/usr/lib set(ENV{VULKAN_SDK} $ENV{ANDROID_NDK_HOME}/sysroot/usr) ``` Notice that **the location of the sysroot has changed since NDK 22**. (see https://github.com/android/ndk/issues/1407) If you prefer using [the latest version](https://developer.android.com/studio/projects/install-ndk#default-ndk-per-agp), check the [BuildSystemMaintainers.md of the NDK document](https://android.googlesource.com/platform/ndk/+/master/docs/BuildSystemMaintainers.md#sysroot) and then put appropriate path for your system. For example, Mac OS users will use the path like this. ```cmake # In android triplets... (e.g. arm64-android.cmake) set(VCPKG_CMAKE_SYSTEM_NAME Android) # ... # If your API level is 30, libvulkan.so is at $ENV{ANDROID_NDK_HOME}/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/lib/aarch64-linux-android/30 set(ENV{VULKAN_SDK} $ENV{ANDROID_NDK_HOME}/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr) ``` By doing this for all android triplets, you can install `vulkan` and the packages that require it. (e.g. `vulkan-hpp`)
`vcpkg install vulkan-hpp:arm64-android` ```console user@host$ ./vcpkg install vulkan-hpp:arm64-android Computing installation plan... The following packages will be built and installed: * vulkan[core]:arm64-android -> 1.1.82.1-1 vulkan-hpp[core]:arm64-android -> 2019-05-11-1 Additional packages (*) will be modified to complete this operation. Detecting compiler hash for triplet arm64-android... ... Starting package 1/2: vulkan:arm64-android Building package vulkan[core]:arm64-android... -- Using community triplet arm64-android. This triplet configuration is not guaranteed to succeed. -- [COMMUNITY] Loading triplet configuration from: /.../vcpkg/triplets/community/arm64-android.cmake -- Querying VULKAN_SDK Environment variable -- Searching /.../Library/Android/sdk/ndk/22.1.7171670/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/include/vulkan/ for vulkan.h -- Found vulkan.h -- Performing post-build validation -- Performing post-build validation done ... Building package vulkan[core]:arm64-android... done Installing package vulkan[core]:arm64-android... Installing package vulkan[core]:arm64-android... done Elapsed time for package vulkan:arm64-android: 35.9 ms Starting package 2/2: vulkan-hpp:arm64-android Building package vulkan-hpp[core]:arm64-android... -- Using community triplet arm64-android. This triplet configuration is not guaranteed to succeed. -- [COMMUNITY] Loading triplet configuration from: /.../vcpkg/triplets/community/arm64-android.cmake -- Using cached /.../vcpkg/downloads/KhronosGroup-Vulkan-Hpp-5ce8ae7fd0d9c0543d02f33cfa8a66e6a43e2150.tar.gz -- Cleaning sources at /.../vcpkg/buildtrees/vulkan-hpp/src/e6a43e2150-4f344cd911.clean. Use --editable to skip cleaning for the packages you specify. -- Extracting source /.../vcpkg/downloads/KhronosGroup-Vulkan-Hpp-5ce8ae7fd0d9c0543d02f33cfa8a66e6a43e2150.tar.gz -- Using source at /.../vcpkg/buildtrees/vulkan-hpp/src/e6a43e2150-4f344cd911.clean -- Performing post-build validation -- Performing post-build validation done ... Building package vulkan-hpp[core]:arm64-android... done Installing package vulkan-hpp[core]:arm64-android... Installing package vulkan-hpp[core]:arm64-android... done Elapsed time for package vulkan-hpp:arm64-android: 144.5 ms Total elapsed time: 1.013 s The package vulkan-hpp:arm64-android is header only and can be used from CMake via: find_path(VULKAN_HPP_INCLUDE_DIRS "vulkan/vulkan.hpp") target_include_directories(main PRIVATE ${VULKAN_HPP_INCLUDE_DIRS}) ```
## Consume libraries using vpckg, cmake and the android toolchain 1. Combine vcpkg and Android toolchains vcpkg and android both provide dedicated toolchains: ````bash vcpkg_toolchain_file=$VCPKG_ROOT/scripts/buildsystems/vcpkg.cmake android_toolchain_file=$ANDROID_NDK_HOME/build/cmake/android.toolchain.cmake ```` When using vcpkg, the vcpkg toolchain shall be specified first. However, vcpkg provides a way to preload and additional toolchain, with the VCPKG_CHAINLOAD_TOOLCHAIN_FILE option. ````bash cmake \ -DCMAKE_TOOLCHAIN_FILE=$vcpkg_toolchain_file \ -DVCPKG_CHAINLOAD_TOOLCHAIN_FILE=$android_toolchain_file \ ... ```` 2. Specify the android abi and vcpkg triplet When compiling for android, you need to select a matching "android abi" / "vcpkg triplet" pair. For example: ````bash android_abi=armeabi-v7a vcpkg_target_triplet=arm-android cmake ... -DVCPKG_TARGET_TRIPLET=$vcpkg_target_triplet \ -DANDROID_ABI=$android_abi ```` ### Test on an example The folder [docs/examples/vcpkg_android_example_cmake](../examples/vcpkg_android_example_cmake) provides a working example, with an android library that consumes the jsoncpp library: *Details* * The [CMakeLists](../examples/vcpkg_android_example_cmake/CMakeLists.txt) simply uses `find_package` and `target_link_library` * The [compile.sh](../examples/vcpkg_android_example_cmake/compile.sh) script enables you to select any matching pair of "android abi" / "vcpkg triplet" and to test the compilation * The dummy [my_lib.cpp](../examples/vcpkg_android_example_cmake/my_lib.cpp) file uses the jsoncpp library *Note*: this example only compiles an Android library, as the compilation of a full fledged Android App is beyond the scope of this document. ### Test on an example, using [vcpkg_android.cmake](../examples/vcpkg_android_example_cmake_script/cmake/vcpkg_android.cmake) The folder [docs/examples/vcpkg_android_example_cmake_script](../examples/vcpkg_android_example_cmake_script) provides the same example, and uses a cmake script in order to simplify the usage. *Details* * The main [CMakeLists](../examples/vcpkg_android_example_cmake_script/CMakeLists.txt) loads [vcpkg_android.cmake](../examples/vcpkg_android_example_cmake_script/cmake/vcpkg_android.cmake) if the flag `VCPKG_TARGET_ANDROID` is set: ````cmake if (VCPKG_TARGET_ANDROID) include("cmake/vcpkg_android.cmake") endif() ```` *Important: place these lines before calling project() !* * The [compile.sh](../examples/vcpkg_android_example_cmake_script/compile.sh) script shows that it is then possible to compile for android using a simple cmake invocation, for example: ````bash cmake .. -DVCPKG_TARGET_ANDROID=ON -DANDROID_ABI=armeabi-v7a ```` ## Consume libraries using vpckg, and Android prefab Archives (AAR files) See [prefab.md](../specifications/prefab.md)