Question about Irrlicht license

[3DModelerMan]

If I want to make a seperate engine project based on Irrlicht what do I have to do? I want to use Irrlicht because it works really well, and it has good code structure. I just want to be able to use DX11 and OpenGL4.x techniques that aren't really possible with Irrlicht the way the API is right now. So I was thinking of writing a bunch of modifications to the engine and creating a branched off project.

[serengeor]

Well it's quite simply explained in the license page:

Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:

1)The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2)Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3)This notice may not be removed or altered from any source distribution.

The first two seam to be straight forward to me at least, though the third one is quite unclear.
Where exactly is this notice?

Actually I also have a question to ask if you don't mind me.

Am I allowed to use some portions of code (some might be just copy pasted, some might be rewritten using irrlicht as a reference) in my own project? do I need to do write that those portions of code are taken from irrlicht?
I mainly took/rewrote some math functions and such, since they looked quite more optimized than what I would write.

[Radikalizm]

As far as I know the only thing you have to do is mark the code you used or altered from irrlicht as such and you should not claim to have completely written it yourself
Besides that I think you can pretty much do as you please

[shadowslair]

The third point means that if you copy-paste a whole source file you shall not remove the first few lines, showing your respect and appreciation to the guys who sacrificed some of their time, so you don`t have to waste yours. That`s all. I doubt anyone will ever have some problem with that.

[Virion]

you can do anything you like with the source code as long as you don't say its entirely written by you.

[serengeor]

And if I used some of the code (a few lines from some functions), should I include the notice in the source or is that unnecessary in that case?
Maybe it would be fair enough to give some credit at the README, or in those source files ?

[Radikalizm]

And if I used some of the code (a few lines from some functions), should I include the notice in the source or is that unnecessary in that case?
Maybe it would be fair enough to give some credit at the README, or in those source files ?

I think it's best to be safe and mention the original authors in both the code and somewhere in a readme file where you reference irrlicht, it's best not to cut corners when it comes to licenses since they can be interpreted rather freely in a lot of cases. This way you're pretty sure you're safe and it doesn't make your life any more difficult

[serengeor]

And if I used some of the code (a few lines from some functions), should I include the notice in the source or is that unnecessary in that case?
Maybe it would be fair enough to give some credit at the README, or in those source files ?

I think it's best to be safe and mention the original authors in both the code and somewhere in a readme file where you reference irrlicht, it's best not to cut corners when it comes to licenses since they can be interpreted rather freely in a lot of cases. This way you're pretty sure you're safe and it doesn't make your life any more difficult

It would be quite hard to mention it in code, because most of the code that I used from irrlicht was kind of used as a reference.
For example I would have used array initialization with a for loop or just set it by hand to 0, but I found from irrlicht that it can be done with some c functions like 'memset', which I haven't really used in my earlier code.

I'll try my best to give irrlicht credits for the code I used from it, though most of it is used indirectly.

Thanks for clarifying this.

[Radikalizm]

Why not just include a small header at the top of the files which use irrlicht code with a small note mentioning this? This is how I handle things when I use zlib-licensed code

If it's mostly things like figuring out how to use memset, then you really don't have to credit anyone btw

[serengeor]

Why not just include a small header at the top of the files which use irrlicht code with a small note mentioning this? This is how I handle things when I use zlib-licensed code

If it's mostly things like figuring out how to use memset, then you really don't have to credit anyone btw

It's not actually figuring out how to use it, it's just that I wouldn't have thought of using it. I assume from the articles I've read that it gains a bit speed, and also makes it a bit simpler to init whole array with 0's.

I used irrlicht source mostly for figuring out how to do things, then I find some resources and implement it my self (to get better understanding of how things work). I will include a header later on I think, but that is if I'm going to release the code anywhere (I will try to, if it works as I want it to).

[mongoose7]

If you are learning to write C++ by reading Irrlicht code, you don't need to acknowledge it. That would just be silly. Really.

[bitplane]

The license says that if you use Irrlicht's source code then you need to include the license if you release your source code. If you're using Irrlicht's source in your project, just rename license.txt to Irrlicht-license.txt and mention Irrlicht and the license file in your readme.

If you aren't releasing any source, you don't need to mention Irrlicht (you will need to mention the JPEG library if your app can load JPGs)

If you're not including Irrlicht's source in your project then there's no need to mention Irrlicht or the license.

[hybrid]

Well, unless you talk about creating your app somewhere. Because you're not allowed to give the impression that you wrote all the render parts on your own! So just to make it easier for yourself mention Irrlicht somewhere

[serengeor]

If you are learning to write C++ by reading Irrlicht code, you don't need to acknowledge it. That would just be silly. Really.

Well, I have to admit that there are/were some places which were new to me and I only got to know them by reading irrlicht sources.

Well, unless you talk about creating your app somewhere. Because you're not allowed to give the impression that you wrote all the render parts on your own! So just to make it easier for yourself mention Irrlicht somewhere

I actually created almost everything from scratch and used irrlicht as a reference. I have only used some math functions which included the floating point error checks, because rewriting them wouldn't really change anything and in the end they would look pretty much the same.

I will include a notice/license if it is required, though it might look a bit confusing to have irrlicht licence and don't have the sources.