Doom3world

I was thinking that it would be nice to have unified code base of Resurrection of Evil and Doom 3. Is there an easy way to merge two code bases together?

The 'd3xp' code is the 'game' code with the differences #ifdef controlled using the D3XP and CTF defines. The is also an additional parameter to the EmitSmoke function which not needed in 'game' logic.

My EMZ mod is based on the d3xp code and works fine with both. If you want a single compiled DLL that will work like that you can simply change the #ifdef blocks with
fileSystem->RunningD3XP() checks at runtime.

So simply using d3xp code will provide Doom 3 functionality + expansion pack functionality ?

So simply using d3xp code will provide Doom 3 functionality + expansion pack functionality (after changing #ifdef) ?

Pretty much. Get yourself a good differencing tool (BeyondCompare, ExamDiff) that can do mass comparisons and diff the 'game' and 'd3xp' folders; you'll get an idea of the level of change.
One thing that does come to mind is that d3xp uses a new 'fullscreenfx' system for post-processing effects which the standard game doesn't have.

That would be a handy system to have, doesn't it? (sounds like something cool)

It's not as handy as you might think. In my opinion, it over-complicates it.

Is it hard to use or .. ?

Agreed. I removed it from my code base.

Can someone please explain what is 'fullscreenfx' system and what does it overcomplicate ?