License for android

[arcangelcaos]

Hello, long play this game. I loved it. Now I'm learning to develop games for android, and there is some material, such as images and music, I could use for my game on android. No source code or the like. Only images and maybe some music.
Would already published in the game, not walking in the forum. My game would be free, but ingame purchases.
Would be legal grab these images and music, as I understand it has GPL ???
thanks

PS: If anyone wants to help is welcome.
(I am Spanish, traslate google)

[Dugi]

You can do that if you give your game a GPL license. That means that you will have to post your source code somewhere (or just send it to anyone who asks for it). As far as I know, most android stuff is in java whose source code can be read, so it's okay. And also to expect that others will re-use your source code in other GPL stuff (but that will allow them to claim that they have written it). GPL licence does not prevent you from selling the game, so you're free to have in-game purchases.

Alternatively, you can contact the artists to allow you to give additional licences to their images.

[Andrettin]

You can do that if you give your game a GPL license.

That is highly debatable. Images and music could be considered "mere aggregation" (indeed, AFAIK that is the mainstream view), and thus the source code of the game wouldn't need to be disclosed.

[iceiceice]

As far as I know, most android stuff is in java whose source code can be read, so it's okay.

I think that actually doesn't really count. It's true that java bytecode can be decompiled, but that is not the "preferred form for making modifications".

I think it even wouldn't be okay if you took the source code, intentionally obfuscated it, compiled it and released that source and binary. Because, the obfuscated code is not the preferred form for making modifications. Similarly I think you can't encrypt the source code and release the cipher text. It's not just "bad behavior that goes against the spirit of free software", I think it's actually just prohibited by the GPL.

[Dugi]

It's true that java bytecode can be decompiled, but that is not the "preferred form for making modifications".

My information may be wrong or outdated, but I was told (by a guy who knew java) that most android apps can be decompressed getting the exact source code even with comments. Not like the decompiled C/C++ code that is very unreadable.

[iceiceice]

Hmm, tbh it's been a really long time since I used java.

Back in the day, when you decompile you would get back similar code more or less but the variable names would all be different and mechanically generated. Losing the variable names can often make it a lot harder to figure what is going on in some complex java program. But maybe they changed it.

[arcangelcaos]

Hello, we go to see. The of java is debatable, but what to my interests me, is if I can use the images and music of this game to realise mine. Afterwards I suppose that I have to put the licence LGPL or GPL to my game. But I have to put it to everything, although it do not use the code source, or only to the images and music of the game?
And if it is all the game, the code source can sell , or always to to be free, since the game will be free?

[Dugi]

The whole game including the images is GPL. The source code of images clearly isn't very concealable, so the GPL on images mostly means that others can re-use them in other GPL projects. If they weren't GPL, there would be nothing allowing you to reuse them at all.

If you make the game GPL, all you need to do is to send the source code to anyone who asks for it and allow them to propagate it (as long as they don't remove the GPL licence). If somebody wanted to avoid paying, he would have to edit the source code to make the purchases free and that requires skill that a vast majority of possible players lack, so don't worry about losing income because of it (the work needed for that might exceed the price of the purchase).

[arcangelcaos]

[quote="Dugi"]If they weren't GPL, there would be nothing allowing you to reuse them at all.
quote]


Sorry for the inconvenience, but my English is not very good. That part I don't understand exactly which means. I have understood that if uses these images GPL must be GPL, but and the source code if I don't use any GPL code?

[iceiceice]

The GPL says that you can reuse, modify, and redistribute GPL content, and charge money for it if you wish, but that if you make a new copyrightable work (derivative work) using that content, the new work can only be distributed under the terms of the GPL.

If you can think of the game engine as being one copyrightable work, and the game itself as being another, separate work, then you can have one of them under one license and one under another. So you could use some GPL art with a non-GPL engine.

Copyright law is sometimes complicated though, and it varies from country to country. I'm not sure if *all* games can be said to have an "engine" in this manner.

For many countries and many games, it seems that that interpretation works, since many people do it.

If for some reason in your case that interpretation doesn't work, then all of them would have to be under the same license I guess.

I am not a lawyer.

[Andrettin]

The GPL says that you can reuse, modify, and redistribute GPL content, and charge money for it if you wish, but that if you make a new copyrightable work (derivative work) using that content, the new work can only be distributed under the terms of the GPL.

If you can think of the game engine as being one copyrightable work, and the game itself as being another, separate work, then you can have one of them under one license and one under another. So you could use some GPL art with a non-GPL engine.

Copyright law is sometimes complicated though, and it varies from country to country. I'm not sure if *all* games can be said to have an "engine" in this manner.

For many countries and many games, it seems that that interpretation works, since many people do it.

If for some reason in your case that interpretation doesn't work, then all of them would have to be under the same license I guess.

I am not a lawyer.

I agree.

[YetAnotherGameDev]

Hello to everyone, my first post here.

I've read all posts above. And I want to repeat things I've understood to clear points:
1. If im gonna use BfW art I must make whole game opensourced or send sources to any who asked for it.
2. I cant just say in credits - "Art are under GPL and hereis link to GPL license and BfW game", while leaving game close sourced.

If i undestand everything right, then I have another Q:
1. Can I leave source code closed, but donate 30% of income to BfW foundation?
OR
2. Make project opensourced, except multiplayer library and in-app purchasing module?

P.S. I dont mind making project opensourced, but want to know all options.

[Pentarctagon]

You might get more responses if you made your own thread for your question. The Game Development forum would also be a more appropriate place to be asking, since this is related to a non-Wesnoth game.

[YetAnotherGameDev]

Thank you, kind moderator, I will do so.