Building Doom 3 On Linux With Eclipse

[OrbWeaver]

Has anybody successfully set this up to work yet? I have got Eclipse to compile the D3 SDK code, but for some reason it (or Scons, I don't know which) is not using an incremental build - instead the entire project is rebuilt from scratch even if only a single file has changed.

 

Is there some flag you have to set in either Eclipse or SCons to use an incremental build, or is there some other problem which causes one of the tools to think that an complete rebuild is necessary?

[sparhawk]

Don't know if anybody paid much attention to the linux port yet. There are some parts in the code that need to be ported anyway, so TDM will not work out of the box on Linux and Mac.

[OrbWeaver]

I am just using the vanilla D3 SDK at the moment, I don't have the TDM source code. I would like to get into a state where "hacking" on the D3 source is easy to do with Eclipse, which I find a particularly user-friendly IDE.

[OrbWeaver]

OK, sorted it. For some reason SCons did not appear to be accessing the file signatures correctly when run under Eclipse causing it to perform a complete rebuild everytime.

 

I added the following line to src/SConstruct to tell SCons to use file timestamps rather than its own hash database to detect changes:

 

SourceSignatures('timestamp')

 

Now the problem appears solved.

[Ishtvan]

@Spar, would you say the things we have to get working in order to port to Linux are the rendering pipe for the lightgem, and the keyboard handler? Hopefully the keyboard handle should be pretty do-able, if we can find the source for one for Linux we can put it into the linux version of the src and make sure the outer function calls are the same (maybe we'll have to write some sort of outer function layer so that the calls within D3 to see which keys are pressed are translated into the specific kb handler calls for the platform?)

[OrbWeaver]

Why does TDM need its own keyboard handler? Is the standard D3 functionality not sufficient?

 

I have also set up GtkRadiant so it compiles and builds properly under Eclipse, which would actually make parallel development very streamlined, especially with the really tight CVS/SVN integration.

[Gildoran]

Yes, the D3 keyboard handler can only have up to 8 "buttons".

[sparhawk]

@Spar, would you say the things we have to get working in order to port to Linux are the rendering pipe for the lightgem, and the keyboard handler?

 

Yes. The pipe stuff should be easy and pretty straightforward, but I'm not sure about the keyboardhandler.

 

Hopefully the keyboard handle should be pretty do-able, if we can find the source for one for Linux we can put it into the linux version of the src and make sure the outer function calls are the same (maybe we'll have to write some sort of outer function layer so that the calls within D3 to see which keys are pressed are translated into the specific kb handler calls for the platform?)

 

Finding the source for the keyboardhandler is easy. I can give it to you right now. After all, this is Linux and I have all kind of kernel sources on my system. The problem is NOT to get the source, but to properly make it work in the Linux/Unix environment.

[sparhawk]

Why does TDM need its own keyboard handler? Is the standard D3 functionality not sufficient?

 

In Doom 3 there are buttons and impulses. impulses can be an unlimited number (i.e. as many as you keyboard has keys), but buttons are limited to eight. Several of them are already used up like ATTACK, MOVE FORWARD, LEFT, RIGHT, BACKWARD so there are only three left. Because of a bug it's actually onlyu two left now, but I think this was fixed in the latest patch. Nevertheless if you want to have leaning reacting properly, instead of a toggle, then we need three directions for leaning already, which leaves no room for other stuff. I implemented a solution that you can make all keys into buttons, and this has to be ported on Linux as well.

[Ishtvan]

Finding the source for the keyboardhandler is easy. I can give it to you right now. After all, this is Linux and I have all kind of kernel sources on my system. The problem is NOT to get the source, but to properly make it work in the Linux/Unix environment.

 

Could you explain what "make it work" means in more detail? I'm not trying to argue, just curious.

[sparhawk]

Well, the problem is that there is no direct keyboard handler in Unix. You are reding data from a terminal. I don't know how it would work if I would start to processes reading from the same terminal, I guess it simply wouldn't work. In Windows this is easier, because the API provides an interface for such a situation, but I'm not aware of such a mechanism on Unix. The code for that part is in the non-accessible area of Doom 3. the one where we have no keycard for. So we probably can't even take it from the keyboard and feed it in. But I have to look at this in more detail, because I'm not THAT good in such deep down Unix programming and usually you don't really need to ensure such hardware access. It might even be needed to write a kernel modul to support what we need. Sounds harder than it is though, because I experimented with that some time ago.