Copyright worries (OpenGL)

So, I bought 2 books about Opengl terrain programming. I understand most of the basic and advanced concepts there with the help of the book and their codes.

I used it on my engine and planning to put my engine in sourceforge. I didn't use most of the codes used by the book because it uses immediate mode which is really slow. So, I rewrite most of the codes and algorithm for building the vertices and drawing it with the use of vertex buffer array and buffers and managed to optimized the code and get a great performance.

Now, I'm just worried that they ( the author of that book ), sue me. lol.

What is the license agreement for the code in the book?

If you compare my codes and the author coded, you really didn't noticed that I got it from that book because it was completely ported from the old immediate mode to vertex array/vbo

Is it illegal to do such thing? I got the idea from others do my own and publish it. Sorry, this is the first time I'm going to publish what I mostly doing this past few months.

Here's the agreement:

The enclosed software is copyrighted by the copyright holder indicated on the
software disc. You are licensed to copy the software onto a single computer for use by
a single user and to a backup disc. You may not reproduce, make copies, or distribute
copies or rent or lease the software in whole or in part, except with written permission
of the copyright holder(s). You may transfer the enclosed disc only together with this
license, and only if you destroy all other copies of the software and the transferee
agrees to the terms of the license. You may not decompile, reverse assemble, or
reverse engineer the software.

My opinion? I think it's ok and goes well under the concept of Fair Use.

- You used code from a book that uses that code exactly to teach you how to do things. That alone is a showstopper for most lawsuits concerning teaching books. But...

- You also didn't copy the code verbatim. Instead simply reapplied the algorithms under a different concept approach. The judge at this point is already going red eyed at the company that filled the lawsuit on you.

- Finally, you didn't use that new code to write another teaching book, which could constitute a problem since you would be competing directly with this book. Instead you wrote an engine. Exactly what the book was teaching how to. You applied the knowledge in the book. You did your part and the book authors did theirs. At this point, it becomes decided the court charges are on the publisher. You walk.

Btw, as far as I'm concerned, those book of yours are already a success story. You should email the authors and thank them as a form of encouragement. Many books out there don't ever deliver what they promise. Yours obviously did!

Originally Posted by sarah22

If you compare my codes and the author coded, you really didn't noticed that I got it from that book because it was completely ported from the old immediate mode to vertex array/vbo

Switching GL code over to use VBOs rather than the immediate mode drawing commands is a pretty substantial rewrite. In that case, IMO, you are just following an algorithm, and not so much copying code. Probably the writers of the book did not invent those either, eg, there are only a few ways to do shadow mapping, but most books on 3D graphics will have a section on one of two or three methods, possibly including example code. They didn't invent the method, they are just describing it, and the example code is part of the description.

If you take the example code, make it work using VBO's, but draw the exact same object (a robot or whatever) , then that probably deserves investigating a copyright but presumably you are not doing that.

Could someone guess where you learned your shadow mapping just by looking at your code? Maybe, but I bet they could just as easily guess a bunch of sources you've never even seen. Only so many ways to skin a cat. I doubt very much any author has ever gone after anyone claiming "You learnt programming from me! I want credit now for everything you do!"

The books I've seen where the author claims to be describing a method invented by him/her, they usually seem to be encouraging people to use it anyway. Remember, they get money for the book, as I am sure they are aware, and (hopefully) the people who actually get publishing contracts have some knowledge to offer their readers. If you take a header/library from a cdrom and use some of the functions verbatim, then you should leave the licence notice intact.

But that is pretty different than learning by example and adapting to suit your own purposes. As someone pointed out in your last thread, supposedly the linked list is patented, but that is (patently) absurd and clearly not enforced or enforceable. Who would want to?

If I was the author of a book which teaches a certain kind of programming, and the book included examples of how to do that kind of programming, and I heard that somebody bought the book and used my examples of how to do something, and I got upset about it...

Well, I think that would make me a moron.

Do you think if the author wanted to protect the code from being used by anybody that he would publish it in a BOOK?

Originally Posted by brewbuck

Do you think if the author wanted to protect the code from being used by anybody that he would publish it in a BOOK?

LDD3 -- the copy notice says something like if you use the code that is in this book then you are deriving work from it, thus your code must also wear the label GPL-V2 or above.

I had some words with the author. I don't think I'd ask him for any help right now. Think he may be a bit ticked off at me.

Originally Posted by Kennedy

LDD3 -- the copy notice says something like if you use the code that is in this book then you are deriving work from it, thus your code must also wear the label GPL-V2 or above.

I had some words with the author. I don't think I'd ask him for any help right now. Think he may be a bit ticked off at me.

Well, the code has a license agreement of course. I'm just saying that the license agreement is probably not "You can't use it under any conditions." You don't publish code that you don't want anyone to use.

Copyright or copyleft, is still has to pass the Fair Use barrier. If it does, you can throw away the original license. Completely.

Edit: should be noted at this point that there's no copyleft concept under the law. Copyleft material is still copyright material. And exactly why it doesn't matter if it is GPL or some commercial license. When it comes to the matter of judging fair use all it matters is the 4-factor balancing test. And I'll be dammed if any judge will condemn someone who builds a 3D engine from code on a book that teaches how to build a 3D engine!

Originally Posted by Mario F.

should be noted at this point that there's no copyleft concept under the law

I think you were the first to mention copyleft in this thread though

Originally Posted by Mario F.

And I'll be dammed if any judge will condemn someone who builds a 3D engine from code on a book that teaches how to build a 3D engine!

You might be damned if a reader used a substantial portion of the code without complying with the license. sarah22's description gives me the impression that fair use will apply, but I do not think that it is always the case that code from such a book can be used as if fair use always applies to its use.

That said, I am not a lawyer and this is not legal opinion.

Originally Posted by laserlight

I think you were the first to mention copyleft in this thread though

No, not really. I was replying to the possibility of a GPL license in Kennedy's reply.

You might be damned if a reader used a substantial portion of the code without complying with the license. sarah22's description gives me the impression that fair use will apply, but I do not think that it is always the case that code from such a book can be used as if fair use always applies to its use.

That's something that was crossing my mind too. Say the book ends with the full code for an engine protected under some form of copyright (copyleft or not) and that's what sarah22 used to create their own engine. Well, I must confess I will not be so assertive as before in that case.

It will depend really on the level of changes to the original code it requires to go from immediate mode to vertex array, or something (I have no idea what it entitles). If the code simply served as a platform for her own work and the end result is an entirely different beast, I don't think how one can support -- in the context of a teaching book -- their copyright was violated.

IF you make something out of the example given AND NOT a copy of the original
example THEN you are free to distribute or do anything as you like with it.

however

IF you use the example given 'as is' AND you distribute it online or commercially,
THEN you will get sued.

if you examine these two quotes (i gave) clearly, you will get hold of the
situtation.

UltraKing227, exactly who are you quoting? Recall that the right to prepare a derivative work ("make something out of the example given") and to distribute it falls under copyright.

correct, and the GPL attempts to restrict that right by effectively stating that any derivative work IS the original work and therefore belongs to the owners of that original work.

The GPL has no business in this conversation at all.