Using filament in C++ android project

[wdfsj]

Hi,

I am trying to link the filament libraries generated by the step 3 in this documentation for a C++ android project (manifest contains just a native activity) . cmake was only run for aarch64. I have built filament for android on windows and am able to run all samples (desktop and android).

To link filament into the C++ android project, I have modified the existing CMakeLists.txt file of the project by adding the following

set(filament_DIR "C:/home/user/filament/out/android-release/filament")
set(ANDROID_ABI "arm64-v8a")

function(link_lib NAME)

    add_library(${NAME} SHARED IMPORTED)
    set_target_properties(${NAME} PROPERTIES IMPORTED_LOCATION
        ${filament_DIR}/lib/${ANDROID_ABI}/lib${NAME}.a)
    target_include_directories(${TARGET} PRIVATE ${filament_DIR}/include/)
    target_link_libraries(${TARGET} ${NAME})
endfunction()

link_lib(filament)
link_lib(backend)
link_lib(utils)

target_link_libraries(${TARGET} GLESv3 EGL android)

And following lines have been added to one of the C++ source files.

#include <filament/Engine.h>
#include <filament/Renderer.h>

void main(struct app* app) {
  filament::Engine* mEngine =  filament::Engine::create(filament::Engine::Backend::DEFAULT);
  ....
}

This produces lot of the following errors during the build

C:/home/user/apps/filament/out/android-release/filament/lib/arm64-v8a/libutils.a(JobSystem.cpp.o): In function `utils::JobSystem::execute(utils::JobSystem::ThreadState&)':
JobSystem.cpp:(.text._ZN5utils9JobSystem7executeERNS0_11ThreadStateE+0x1c): undefined reference to `__aarch64_ldadd4_relax'
JobSystem.cpp:(.text._ZN5utils9JobSystem7executeERNS0_11ThreadStateE+0x28): undefined reference to `__aarch64_ldadd8_acq_rel'
JobSystem.cpp:(.text._ZN5utils9JobSystem7executeERNS0_11ThreadStateE+0x6c): undefined reference to `__aarch64_cas8_acq_rel'
JobSystem.cpp:(.text._ZN5utils9JobSystem7executeERNS0_11ThreadStateE+0xac): undefined reference to `__aarch64_ldadd4_relax'
JobSystem.cpp:(.text._ZN5utils9JobSystem7executeERNS0_11ThreadStateE+0xbc): undefined reference to `__aarch64_cas4_acq'
JobSystem.cpp:(.text._ZN5utils9JobSystem7executeERNS0_11ThreadStateE+0xdc): undefined reference to `__aarch64_swp4_rel'

Can someone give any insights as to how to fix this. Also, are there are any filament examples where the entire android app is purely written in native C++?

Thanks

[wdfsj]

This was happening because the ndk versions used to compile filament and the other android project were different. Once the same ndk version was used, the issue was resolved.