Linking External Libraries Using Ndk, Gradle & Cmake In Android Studio

I've come back to Android development after a gap and my old ANT based build chain no longer seem to function (that's a separate issue) with the latest SDK, so I'm trying to do thi

Solution 1:

You must take care of ABI incompatibility. You are building libanthracite-lib.so for x86_64, so you need the same variant of libBullet.a. If you only need armeabi-v7a, you must specify this in build.gradle, e.g.

android {
  externalNativeBuild {
    cmake {
      path 'CMakeLists.txt'
    }
  }
  defaultConfig {
     ndk {
        abiFilters 'armeabi-v7a'
    }
    externalNativeBuild {
      cmake {
         arguments'-DCMAKE_VERBOSE_MAKEFILE=ON'
      }
    }
  }
}

In your E:\prog\anthracite\gradle\AnthracitePlayerAPI21\app\CMakeLists.txt

add_library(bullet_lib STATIC IMPORTED)
set_target_properties(bullet_lib PROPERTIES IMPORTED_LOCATION
 ${LIBBASE}/bullet3/build3/Android/obj/local/${ANDROID_ABI}/libBullet.a)
target_link_libraries(my_project_name bullet_lib android log EGL GLESv2) 

The order of libraries in target_link_libraries may be important, so keep static libs on the left.

I guess you build libBullet.a with ndk-build. You can create a separate library module (let's call in bullet_module) to your AS Project, even if it has no Java files, and point it to the Android.mk:

apply plugin: 'com.android.library'

android {
  compileSdkVersion 27

  defaultConfig {
    ndk {
      abiFilters 'armeabi-v7a'
    }
    externalNativeBuild {
      ndkBuild {
        targets 'Bullet'
      }
    }
  }
  externalNativeBuild {
    ndkBuild {
      path "${LIBBASE}/bullet3/build3/Android/jni/Android.mk"
    }
  }
}

Now you can change your CMakeLists.txt to look at results of bullet_module build:

set_target_properties(bullet_lib PROPERTIES IMPORTED_LOCATION
  <path/to/bullet_module>/build/intermediates/ndkBuild/debug/obj/local/${ANDROID_ABI}/libBullet.a)