|Note: You can also download binaries or automate the compilation with ncline.|
Before starting download and install CMake. In order to build the nCine library for Android you need to clone or download some git repositories:
- nCine, this is the main project
- nCine-android-libraries, this project contains CMake scripts to build dependency libraries
- nCine-data, the data files for the nCine tests (optional but recommended)
- ncPong, a Pong game built with the nCine that is useful as an example project (optional)
- ncPong-data, the data files for the Pong game (optional)
For the nCine project to automatically find the dependencies and the data it is important that all repositories are in the same directory.
For the nCine project to automatically find the dependencies and the data it is important that all repositories are in the same directory and that their name is the same as the repository name. This means that if you decide to download a ZIP file generated by GitHub from a branch, you need to remove the branch suffix so that the directory name is the same as the repository one.
For example, if you download
nCine-master.zip and extract it, you should rename the
nCine-master directory to
nCine to better follow the rest of the istructions.
Note: Remember that for every project, depending on your needs, you can specify
-D CMAKE_BUILD_TYPE=Debug or
-D CMAKE_BUILD_TYPE=Release at the CMake generation phase.
Build the dependency libraries
As for the other projects, the Android dependencies are built using CMake.
You will also need the Android NDK, at least r19, in order to compile the code.
You can set its path in the
ANDROID_NDK environment variables, or in the
NDK_DIR CMake variable.
Two more variables need to be set before running CMake:
ARCHhas to be set to one of the supported architectures:
PLATFORMhas to be set to a number specifying the Android API level
You can now invoke CMake to configure the libraries:
cmake -S nCine-android-libraries/ -B nCine-android-libraries-build -D ARCH=arm64-v8a -D PLATFORM=21 -D CMAKE_BUILD_TYPE=Release
Then invoke CMake again to compile them:
cmake --build nCine-android-libraries-build
Note: The CMake scripts use the ExternalProject module and sometimes they define a patch step.
If you are on Windows you might need to install a
patch command and either specify it modifying the scripts in question or make it available through the syetem path variable.
Build the nCine library
To enable the compilation of the Android version of the library you need to switch on the
NCINE_BUILD_ANDROID CMake variable.
Similar to the dependency libraries project, you can set the NDK path through an environment variable or via CMake.
cmake -S nCine -B nCine-build -D NCINE_BUILD_ANDROID=ON cmake --build nCine-build
To assemble the APK you need to install Gradle and to setup two Gradle properties,
ndkDir. The first one is the path to the CMake executable while the second is the NDK path.
You can specify those properties using the
gradle.properties file or on the command line, using
It is now possible to build the APKs of the default test.
cd nCine-build/android gradle build -PcmakeCommand=<path/to/cmake> -PndkDir=<path/to/NDK>
Note: When invoking
gradle on Windows the generator used by CMake to compile is
NMake Makefiles. It would only work if you have
nmake in your system path variable.
There is an additional CMake option that would carry on this step automatically, invoking Gradle and passing the two needed properties.
cmake -S nCine -B nCine-build -D NCINE_BUILD_ANDROID=ON -D NCINE_ASSEMBLE_APK=ON
Build the samples
If you have nCine built somewhere with Android support enabled you can invoke Gradle as follows.
gradle build -PcmakeCommand=<path/to/cmake> -PndkDir=<path/to/NDK> -p <path/to/built/android/dir> -PbuildDir=<builddir> --project-cache-dir=<builddir>/.gradle
Build the ncPong example
In order to build the Android version of ncPong you need to switch on the
NCPROJECT_BUILD_ANDROID CMake variable and then run Gradle to build the APK.
You will also need to specify the
nCine_DIR variable. It should point to the engine build directory or, if you are using an archive downloaded from the artifacts repository, to the directory inside the engine that contains the
cmake -S ncPong -B ncPong-build -D NCPROJECT_BUILD_ANDROID=ON -D nCine_DIR=<current directory>/nCine-build cd ncPong-build/android gradle build -PcmakeCommand=<path/to/cmake> -PndkDir=<path/to/NDK>
Note: Should you decide to build the ncPong example, remember that you will need the
ncPong-data directory at the same level.
For reference you can have a look at the continuous integration scripts: