Selling a game made with GZDoom?

[DrPyspy]

I have many questions regarding the possibility of selling a game made using GZDoom.

First of all, what are the 'requirements' for bundling GZDoom with the game? I'm told that because of the GPL license, I would need to provide a link to the GZDoom repository and a copy of the license. I've been researching information on the GPL license and what I've seen lines up with what I'm told. Are there any requirements beyond these?

My second question regards the GPL license. The GPL states the following in this section:

However, if someone pays your fee and gets a copy, the GPL gives them the freedom to release it to the public, with or without a fee.

If GZDoom was bundled with the game, would this force my game's assets to be freely distributable as well?

My third question regards the contents in gzdoom.pk3, specifically the copyrighted content. Can I find a full list of the content that would need to be removed? I was also wondering about the ZScript definitions for Doom/Heretic/Hexen enemies. Do they fall under copyright? Would I need to remove them to sell my game in the event that I bundle GZDoom with my game?

[wildweasel]

I Am Not A Lawyer, but as far as I'm aware, the assets can be under a different license from the code. This is exactly the way Doom et al have been open-sourced: not unconditionally, but for the source code only, with the provision that the assets are still under copyright and indicated for commercial use only.

[Kinsie]

If GZDoom was bundled with the game, would this force my game's assets to be freely distributable as well?

No, this refers to the engine code.

My third question regards the contents in gzdoom.pk3, specifically the copyrighted content. Can I find a full list of the content that would need to be removed?

Probably not a complete list, but off the top of my head: The Wolf3D dogs, the bigfonts, the game-specific cursors, pretty much every sound except dssecret, the icechunk, beta and weapon pickup sprites...

I was also wondering about the ZScript definitions for Doom/Heretic/Hexen enemies. Do they fall under copyright? Would I need to remove them to sell my game in the event that I bundle GZDoom with my game?

These are converted from GPL codebases, so you should be okay.

[Rachael]

Nash (and probably others before him) did a pretty good job in forking GZDoom-GPL to remove a lot of infringing content. I think if you were to use the graphics and sounds in his PK3 and leave everything else as-is (and replace GZDoom's default application icon) you should be okay.

[Nevander]

If that content is infringing, how is it allowed to even exist in gzdoom.pk3 to begin with? Is it because the engine is free? Since the question is about selling something then I guess that's where the issue comes in right?

[Nash]

Can I find a full list of the content that would need to be removed? I was also wondering about the ZScript definitions for Doom/Heretic/Hexen enemies. Do they fall under copyright? Would I need to remove them to sell my game in the event that I bundle GZDoom with my game?

Nash (and probably others before him) did a pretty good job in forking GZDoom-GPL to remove a lot of infringing content. I think if you were to use the graphics and sounds in his PK3 and leave everything else as-is (and replace GZDoom's default application icon) you should be okay.

https://github.com/nashmuhandes/GZDoom- ... c05b98f4ca and click on the "228 changed files" for a full list of the offending assets.

Also don't forget the executable icons...

Windows: src/win32/icon1.ico
Mac: src/posix/osx/zdoom.icns
Linux: src/posix/zdoom.xpm

And the error reporter on Windows contains a potentially offensive graphic: src/win32/deadguy.bmp

[Rachael]

Actually, I think this might be a good idea to use as a base for the archive split that Graf originally proposed. I might work on that, along with putting in code to load the infringing archive when it's available and to have it completely optional.

[Nash]

Sounds like a good idea, although arguably the quality of those replaced assets could be dramatically improved before I'd consider them to be production-ready. =P I guess those could be improved with time as artists could contribute to it... ?

[Rachael]

Well ideally - most users won't even notice the difference because the optional archive will be loaded. But yes, over time, the "required" assets (to get GZDoom to even load) could definitely be improved.

[Rachael]

Aaaand done. I'm going to leave it in a branch for now because I want Graf to look at it and make sure he's okay with the new assets.

[Nash]

The Mac icon is missing. :D Unfortunately I was only aware of this file much later after GZDoom-GPL was discontinued so I never bothered to update the repo. There's probably some small program out there that can produce the .icns file needed.

[Rachael]

I'm really not having a whole lot of luck finding an online converter to convert the icon to mac format.

Maybe that's why it's a good thing this is still in a branch?

[_mental_]

I can create Mac icon if needed. But to make icon look great on any OS we need several image sizes, from 32x32 to 512x512.
Downloads section on zdoom.org already has the icon for GZDoom (without GPL letters though) but it's the only one size, 256 pixels.

[Rachael]

Tormentor made the original icon, we can see if he has the original file still (hopefully he used vector for the original outlines) and see if he's willing to give us a 512x512 version - after that, it should be easy to make the smaller versions. Also, the GPL letters are not needed, since this is GZDoom proper and not the fork.

Also - feel free to commit directly to that branch. I mostly put the stuff I did in there to get this project moving - since this was proposed a long time ago but never done. I feel, now, that it is at least in a state that a potential game author can actually use it as a base without having to recompile GZDoom on their own - from here, I think it can definitely be improved upon further.

[Kinsie]

And the error reporter on Windows contains a potentially offensive graphic: src/win32/deadguy.bmp

Less "offensive", more "infringing" since it's just a Doom sprite.

Best solution would be to replace it with a copy of UNKNA0.png.