Tuesday, July 14, 2009

IWAD Question with WiiDoom (alternate subject: Hello again!)

Yes, I'm still alive and keeping an eye on the homebrew scene, more recently lately...

I got this question in my email and wanted to answer it publicly, since it's a very good question, and one I asked myself midway through WiiDoom:

"...i was under the impression that the same engine was used for the Hexen/Heretic games but when i try and add those wad files they dont even read. i was wondering if this would be a pain to ask for or if not, would you know someone who would be able to work in a compaitibility or new wii homebrew that would allow us to play these old games as well..."

Here's the thing about the Doom engine, as it relates to Doom,Hexen, and Heretic. This is going on memory, but it's still somewhat fresh in my brain LOL.

The Doom engine was somewhat tailored to the game it was packaged with (i.e. Doom, Heretic, Hexen) and the engine will look for the specific IWADs, as well as checking the IWAD once it opens them to look at the header. It *really* gets the version of Doom (I, II, Final, Ultimate) from the header, and turns on various features based on that. It seems that with each new game id software made, they enhanced the engine, adding better special FX.

It's very easy to add the checks for the other games (Hexen, Heretic), but then the various features that need to be enabled have to be added as well. I think it was Hexen that had some special things like the fog. The fog effect would have to be added, which would touch quite a number of files (probably the r_* files). ZDoom and a few other 3rd party engines had done this, so I know it's possible, it's just not a very easy thing to do. It is much easier (and cleaner) to port the individual engines over. I looked into porting hexen over, and was messing around with that before I basically ran out of time to work on homebrew. I'd REALLY love to do that again.

If anyone else has a question, let me know. I'm not saying that I'm resuming development (yet), but I am really considering it once another side project of mine is finished.