android NDK，在另一个android NDK项目中使用已编译的.so库中的函数

my problem is that, I don't know how to call functions form .so library. I have successfully compiled NDK library spatialite-android and have no problems to use it in android Java application. But I have no idea how exactly use it in another NDK project. I have added it in Android.mk file:my problem is that, I don't know how to call fu