Qt Core wrapper for librtclient
$ git clone git://darapsa.org/qrtclient.git
$ mkdir build-qrtclient-Desktop-Debug
$ cd build-qrtclient-Desktop-Debug
$ cmake -DCMAKE_BUILD_TYPE=Debug ../qrtclient
or
$ mkdir build-qrtclient-Android_for_armeabi_v7a_arm64_v8a_x86_x86_64_Clang_Qt_5_15_2_android-Debug
$ cd build-qrtclient-Android_for_armeabi_v7a_arm64_v8a_x86_x86_64_Clang_Qt_5_15_2_android-Debug
and then
$ cmake -DCMAKE_TOOLCHAIN_FILE=/opt/android-sdk-update-manager/ndk/21.3.6528147/build/cmake/android.toolchain.cmake -DCMAKE_FIND_ROOT_PATH=/usr/local/Qt/5.15.2/android -DANDROID_NATIVE_API_LEVEL=21 -DANDROID_ABI=arm64-v8a -DCMAKE_INSTALL_PREFIX=/usr/local/Qt/5.15.2/android -DCMAKE_BUILD_TYPE=Debug ../qrtclient
or
$ cmake -DCMAKE_TOOLCHAIN_FILE=/opt/android-sdk-update-manager/ndk/21.3.6528147/build/cmake/android.toolchain.cmake -DCMAKE_FIND_ROOT_PATH=/usr/local/Qt/5.15.2/android -DANDROID_NATIVE_API_LEVEL=16 -DANDROID_ABI=armeabi-v7a -DCMAKE_INSTALL_PREFIX=/usr/local/Qt/5.15.2/android -DCMAKE_BUILD_TYPE=Debug ../qrtclient
or
$ cmake -DCMAKE_TOOLCHAIN_FILE=/opt/android-sdk-update-manager/ndk/21.3.6528147/build/cmake/android.toolchain.cmake -DCMAKE_FIND_ROOT_PATH=/usr/local/Qt/5.15.2/android -DANDROID_NATIVE_API_LEVEL=16 -DANDROID_ABI=x86 -DCMAKE_INSTALL_PREFIX=/usr/local/Qt/5.15.2/android -DCMAKE_BUILD_TYPE=Debug ../qrtclient
or
$ cmake -DCMAKE_TOOLCHAIN_FILE=/opt/android-sdk-update-manager/ndk/21.3.6528147/build/cmake/android.toolchain.cmake -DCMAKE_FIND_ROOT_PATH=/usr/local/Qt/5.15.2/android -DANDROID_NATIVE_API_LEVEL=21 -DANDROID_ABI=x86_64 -DCMAKE_INSTALL_PREFIX=/usr/local/Qt/5.15.2/android -DCMAKE_BUILD_TYPE=Debug ../qrtclient
or so on.
$ make # -jN (with N an integer number of parallel tasks you allow your computer to run for compiling this)
$ sudo make install