How to make android project with additional SDL2_Image library?

Question

Android

The fact is that I managed to make an android project using SDL2 and Android SDK|NDK, but I can’t do it at all with the additional SDL2_Image library.
I wrote what I need in Android.mk and SDL_Activity.java, but the terminal gives the following error:

[email protected]:~/AndroidDevlopment/SDL_DEmo/jni$ '/home/good_inc/Doc/AndroidNDK/ndk-build' 
[armeabi] Install        : libSDL2.so => libs/armeabi/libSDL2.so
[armeabi] SharedLibrary  : libSDL2_image.so
/home/good_inc/Doc/AndroidNDK/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: /home/good_inc/AndroidDevlopment/SDL_DEmo/obj/local/armeabi/objs/SDL2_image/IMG_webp.o: in function IMG_InitWEBP:/home/good_inc/AndroidDevlopment/SDL_DEmo/jni/SDL_Image/IMG_webp.c:123: error: undefined reference to 'WebPGetFeaturesInternal'
/home/good_inc/Doc/AndroidNDK/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: /home/good_inc/AndroidDevlopment/SDL_DEmo/obj/local/armeabi/objs/SDL2_image/IMG_webp.o: in function IMG_InitWEBP:/home/good_inc/AndroidDevlopment/SDL_DEmo/jni/SDL_Image/IMG_webp.c:123: error: undefined reference to 'WebPDecodeRGBInto'
/home/good_inc/Doc/AndroidNDK/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: /home/good_inc/AndroidDevlopment/SDL_DEmo/obj/local/armeabi/objs/SDL2_image/IMG_webp.o: in function IMG_InitWEBP:/home/good_inc/AndroidDevlopment/SDL_DEmo/jni/SDL_Image/IMG_webp.c:123: error: undefined reference to 'WebPDecodeRGBAInto'
collect2: ld returned 1 exit status
make: *** [/home/good_inc/AndroidDevlopment/SDL_DEmo/obj/local/armeabi/libSDL2_image.so] Error 1

How to fix?

Answer 1

If WebP is not needed, then the easiest way is to change true to false in the SDL2_image/Android.mk file, in the line SUPPORT_WEBP := true
If needed, then either copy the SDL2_image/external/libwebp-0.3. including it from root Android.mk. I faced the same problem in SDL2_audio and didn't understand how to include it properly. I had to copy.

Answer 2

Not all dependencies are included. Maybe, maybe the source. This is indicated by the absence of some functions, WebPDecodeRGBAInto for example.