Android/ios not depending on StbImageLoader

[8Keep]

After 2cd8aeb, General.cfg now registers image loaders that live in jme3-plugins:

• StbImageLoader for jpg, bmp, gif, png, jpeg, tga, psd, hdr
• WebpImageLoader for webp

jme3-android and jme3-ios both include General.cfg, but they only depend on jme3-core, not jme3-plugins.

Possible fixes:

• Split the image loaders into a smaller module, for example jme3-image-plugins, and have desktop/android/iOS depend on that.
• Or move the STB/WebP loaders into jme3-core, since General.cfg lives there and registers them.
• Less ideal: make mobile modules depend on all of jme3-plugins.

I prefer the second one I think?

[riccardobl]

My understanding is:

If something depends on an external library it goes in jme3-plugins, if not it goes in jme3-core.
Since these two loaders depends on external libraries, i think they are in the right place.

[8Keep]

I suppose then the other option is that we declare this not a bug, if you depend on png loading, you have to depend on jme3-plugins. But it would be strange to include them by default in the mobile cfg then, because the error you hit is not that clear.

[riccardobl]

I suppose then the other option is that we declare this not a bug, if you depend on png loading, you have to depend on jme3-plugins. But it would be strange to include them by default in the mobile cfg then, because the error you hit is not that clear.

I think the right fix here would be to not crash the engine if the png loader is missing and the dev is not loading a png explicitly.

AFAIK by default it is needed by the engine only for the Default.fnt for the bottom left stats. What if we export the font to j3o so we don't have to depend on any loader?

[riccardobl]

So, the problematic line should be this one:

jmonkeyengine/jme3-core/src/main/java/com/jme3/app/SimpleApplication.java

Line 251 in 3433603

return assetManager.loadFont("Interface/Fonts/Default.fnt");

[riccardobl]

@stephengold this pr #2832 should make the png loader non essential for your simple test. If you want to give it a try, feel free.