AndroidNativeImageLoader failing to load

[MeFisto94]

I just tried to start a simple android test application, but the result I got was:

java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader[DexPathList[[zip file "/data/app/com.github.MeFisto94.android.jme3.test-1/base.apk"],nativeLibraryDirectories=[/data/app/com.github.MeFisto94.android.jme3.test-1/lib/x86, /system/lib, /vendor/lib]]] couldn't find "libdecodejme.so"
        at java.lang.Runtime.loadLibrary0(Runtime.java:984)
        at java.lang.System.loadLibrary(System.java:1530)
        at com.jme3.texture.plugins.AndroidNativeImageLoader.<clinit>(AndroidNativeImageLoader.java:23)
        at java.lang.Class.classForName(Native Method)
        at java.lang.Class.forName(Class.java:400)
        at java.lang.Class.forName(Class.java:326)
        at com.jme3.asset.AssetConfig.acquireClass(AssetConfig.java:62)
        at com.jme3.asset.AssetConfig.loadText(AssetConfig.java:86)
        at com.jme3.asset.DesktopAssetManager.loadConfigFile(DesktopAssetManager.java:96)
        at com.jme3.asset.DesktopAssetManager.<init>(DesktopAssetManager.java:89)
        at com.jme3.system.JmeSystemDelegate.newAssetManager(JmeSystemDelegate.java:125)
        at com.jme3.system.JmeSystem.newAssetManager(JmeSystem.java:139)
        at com.jme3.app.LegacyApplication.initAssetManager(LegacyApplication.java:216)
        at com.jme3.app.LegacyApplication.initialize(LegacyApplication.java:593)
        at com.jme3.app.SimpleApplication.initialize(SimpleApplication.java:197)
        at com.jme3.app.AndroidHarness.initialize(AndroidHarness.java:477)

TLDR: Something is wrong with the natives again, I guess.
@riccardobl Do we need to do something more than just adding jme3-android as dependency?
I've only found https://mvnrepository.com/artifact/org.jmonkeyengine/jme3-bullet-native-android but it shouldn't include the Image Loader.

Edit: Either this https://github.com/jMonkeyEngine/jmonkeyengine/tree/master/jme3-android-native should be a separate artifact or part of jme3-android as dependency (I strongly guess and suggest the latter), so I guess that's the problem already.

Certainly missing that in https://github.com/jMonkeyEngine/jmonkeyengine/blob/master/jme3-android/build.gradle though.

Edit2:

Sorry for the misinformation

Actually there is a jme3-android-native artifact, but I don't think it's what we want, is it?
Why would someone omit it? If someone wants to omit it, the AndroidNativeImageLoader needs to be shifted to that artifact, so that it's not visible for the DesktopAssetManager

[stephengold]

I always assumed jme3-android-native was separate because someone circa 2014 couldn't figure out how to combine Java and native code in a single Gradle subproject.

[MeFisto94]

If that is the reason we either should merge them (but that breaks backwards compat) or at least move the NativeImageLoader there, then.

But since it seems to be impossible to load transparent images (I don't know what premultiplied alpha means, v.rgb = v.rgb * v.a?), then it should be even more part of jme3-android

[stephengold]

We could ask @normen about the reason, assuming he still exists.

[normen]

Why jme3-android-native is separate? Because we usually always separated native and java code afaicr. That way you could still use and build everything java without having native compilers, Android NDK and whatnot installed.

Or was that not the question? :)

[MeFisto94]

That's question number one, yes :) Thanks for that!
In the meantime our gradle workflow supports building by downloading prebuilt artifacts.

The question that is the result of this is now:

1. Do we merge jme3-android-native into jme3-android?
2. Do we declare jme3-android-native as a runtime dependency of jme3-android? (More backcompat and confusion)
3. Do we continue like that and make Native Image Loading optional? (I bet in the last 5 years android has added a way to load images without the need of a native library, which is actually a maintenance effort for us)

Does anyone know about that "Premultiplied Alpha only"? @nickidebruyn maybe?

[normen]

Mhm, I'd vote for keeping it separate as well for those reasons. The native code might change, get deprecated, become platform dependent or something like that. This way it's easy to root out the cancer if it becomes malignant ;)

But my vote shouldn't count here anymore as I didn't follow the changes at all for at least a year, if not two. You know best what is what and what works these days.

But as always if you need any help when you end up in a dark corner of the codebase with only some //normen: TODO: WTF lines looking at you or something - I'm here :)

[stephengold]

Declaring jme3-android-native as a runtime dependency of jme3-android seems like the best solution for now.

[MeFisto94]

Things to investigate:
What does the NativeLoader talk about, is this still true in recent Android?
Can we load RGBA Textures on Android at all when this Native Loader isn't available?

Because in addition to 2, we should probably still move the AndroidNativeImageLoader to jme3-android-native, so that just using jme3-android still works when android-native is explicitly removed, I guess

[stephengold]

If jme3-android-native is a dependency, then removing it would be an error (if you're not using Gradle) or very difficult (if you are).