ZDoom

by **Graf Zahl** » Sun Dec 14, 2008 2:08 pm

It's all in the software renderer. I already removed all Build code that was used elsewhere some time ago.

And asking him sure is the decent thing to do. But that's not my concern.

by **skadoomer** » Sun Dec 14, 2008 2:00 pm

Still sounds like a sneaky operation and a dick move to Ken Silverman, at least doing an integration without the curtsy of telling him his software has fallen victim to a licensing conflict that allows this kind of behavior. Does this affect the opengl extensions you've written or is this all contained within the software renderer?

by **Graf Zahl** » Sun Dec 14, 2008 12:54 pm

skadoomer wrote:wait, back up. I thought the duke 3d code being licensed under the GPL was only prevalent to the duke code its-self (this excluded the build portion of it, but applied to the actor extensions and so forth).

I'm almost 100% certain that they didn't fully consider the full implications of the GPL, in particular the 'vampire clause' which is also the root of the entire licensing issue with ZDoom.

This clause states that all code that gets distributed with GPL'ed code as one program automatically falls under the GPL's jurisdiction as well. And the text file coming with the DN source states that Ken Silverman agreed to this distribution. Which would be no problem for him if the Build engine was a separate program that was 'merely aggregated' with the main game. But as we all know that isn't the case. The engine is a fundamental part to make the game even compile. And since he agreed to this distribution he essentially let his code fall under the GPL, whether he wanted to or not.

by **skadoomer** » Sun Dec 14, 2008 12:39 pm

wait, back up. I thought the duke 3d code being licensed under the GPL was only prevalent to the duke code its-self (this excluded the build portion of it, but applied to the actor extensions and so forth). Did they just conveniently throw in their build code in there and slap a GPL license to it? Since Ken licensed (as in sold for whatever use they sought fit) to 3d realms, then this should apply with no problem, as its their property. This is all well and good, but I think you need to have a conversation with Mr. Silverman about the specifics. IIRC, his code has a personal license so he can track where it goes in the internet community and not just get re-absorbed into another commercial market (like PDA's or what have you). I think sneaking around this issue with a "they did it too, so we can do it as well" mentality is the wrong approach here.

by **Woolie Wool** » Sun Dec 14, 2008 12:26 pm

randy wrote:I needed to provide justification? This has already been beaten to death before. GPLing it would mean taking out the entire renderer. What good is the game if you can't see anything?

You could use Duke Nukem 3D's GPL license for the slope code instead of Ken Silverman's license, problem solved.

by **Gez** » Sun Dec 14, 2008 10:25 am

ScummVM uses an LGPL OPL emulator, apparently. fmopl.h fmopl.cpp

by **Graf Zahl** » Sun Dec 14, 2008 9:30 am

Do these other ports even have an OPL emulator? AFAIK they all use SDL_Mixer for music playback, which is one of the shittiest sound libraries available.

by **Spleen** » Sun Dec 14, 2008 9:18 am

Thanks Graf, that made the Build license issues really clear.

Graf Zahl wrote:So if you ask me, that'd leave the OPL emulator as the sole remaining obstacle and I think a solution can be found for that so it doesn't have to be sacrificed completely.

Perhaps code can be lifted from one of the GPL source ports such as Chocolate Doom? Or is this a concern about some extra capabilities of the ZDoom OPL emulator that would have to be re-implemented?

by **MDenham** » Sun Dec 14, 2008 4:41 am

Graf Zahl wrote:I'd say Ken Silverman dug himself a pretty big hole to sink his own license into. Essentially he implicitly relicensed his entire code under the GPL when he agreed to this distribution.

As far as that goes (and I'm not a lawyer, though I play one on TV follow enough of Slashdot's "let's argue over the GPL" moments to be able to give a coherent and correct response in that regard)... if the only differences between the DN version of the renderer and the normal Build source's version are in places that have already been changed, the version currently in the ZDoom source can safely be assumed to have been derived from the DN version (and therefore is safely under the GPL). If some of the differences between the two are still present and unaltered, then you might have an issue - but it should be easily corrected by consulting the DN version of the renderer.

by **Graf Zahl** » Sun Dec 14, 2008 4:23 am

Graf Zahl wrote: 1. Some Build code in the renderer - this is questionable because Duke3D is GPL which would mean that the Build code in there is also GPL - even though Ken himself claims that his code is not GPL. I'd say the license clauses of the GPL would win in this case.

What about this? I had some fun comparing Duke's Build code with Ken's and except for minor changes (far less than anything ZDoom has done to this code) they are identical in all areas that matter.

Although the Build source mentions 'the included license file "BUILDLIC.TXT"' it's nowhere near to be found in the DN distribution - which leaves the GPL as the sole governing body in there.

I'd say Ken Silverman dug himself a pretty big hole to sink his own license into. Essentially he implicitly relicensed his entire code under the GPL when he agreed to this distribution.

So if you ask me, that'd leave the OPL emulator as the sole remaining obstacle and I think a solution can be found for that so it doesn't have to be sacrificed completely.

by **randi** » Sat Dec 13, 2008 11:06 pm

I needed to provide justification? This has already been beaten to death before. GPLing it would mean taking out the entire renderer. What good is the game if you can't see anything?

by **Graf Zahl** » Sat Dec 13, 2008 2:51 am

skadoomer wrote:but i doubt this will happen.

How can it? Randy already said no - without giving any justification.

by **skadoomer** » Sat Dec 13, 2008 12:06 am

Michi wrote:Come on, it can't be that hard!

It probably isn't, but its just a matter of doing the work. In case you can't tell, zdooms development has slowed down in terms of implementing stuff. Sorry to sound pessimistic, but i doubt this will happen.

by **Graf Zahl** » Fri Dec 12, 2008 6:09 pm

There's 2 things left that may pose a problem:

1. Some Build code in the renderer - this is questionable because Duke3D is GPL which would mean that the Build code in there is also GPL - even though Ken himself claims that his code is not GPL. I'd say the license clauses of the GPL would win in this case.
2. The OPL emulator

For everything else free alternatives exist or the code can be relicensed

by **Macil** » Fri Dec 12, 2008 6:03 pm

There was a thread around here somewhere that had a bit of a roadmap on what needed to be done to get zdoom gpl. The biggest thing was replacing the Hexen code, which isn't needed to be done now as that was GPL'ed some time ago.

ZDoom

GPL ZDoom?

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