how hard to make a general HMD wrapper?

[hifidelitygaming]

I've posted a number of times before (though not in months) usually with far more of an interest in older games than newer ones most of the time...

I'm always obsessed with immersion - getting more into the game. Better or unique for their time human interface controllers, more realistic sound including superior but abandoned API's like Aureal, higher resolution graphics, 3d, and HMD's. But not just for new games, because old games are their own unique worlds some of which have never been remade or updated on the newer systems.

Playing the newest games supporting new stuff is of course cool, if you can afford how they've gone all proprietary, ie Nvidia 3d Surround requiring 3d surround rated monitors (ignoring CRT's capable of 120hz on purpose), while simultaneously ditching past game support of things that worked fine on the 2007 driver... i'm not a fan of losing support for any older software or hardware which worked/forcing one to build a custom PC just to play older stuff. (or a series of them in some cases)


What i'm wondering is how difficult would it be to program a software layer to intercept DirectX and OpenGL calls from older games and having them output in the newest formats? I think I posted asking about this in the past (possibly on other forums/didn't check) although I didn't include HMD's at the time due to oversight. Things like the "software triplehead" patch do something a little similar with a virtual rendering buffer letting it output to multiple monitors, i'd like to do something like that but expanded further.

The new Oculus Rift is something i'm looking forward to, yet other people maybe using homebrew hardware, or maybe a modified PS3 HMD and similar... so i'd want it to be a little more open as far as supporting different methods of output and head tracking. I understand there is something called VorpX which does something a little like this, although i'm not up on that project (yet) which even includes support for pre-warping graphics to counter the effect of the optics... it was actually that line that gave me the desire to post. If one could have arbitrary pre-warping ability this could open other possibilities like easier dome projection/something i've wanted to do for a LONG time - with existing software being the trick, does no good to do something supported by only one app or two games.

I'd further love to see some kind of multihead support that supports software edge blending and digital alignment for multiple projectors, possibly even 'smart projector' auto alignment/blending using a camera pointed at your projection surface edges since I can imagine that being tedium without end otherwise any time the rig is bumped in the slightest degree... even if such an ability were only added later/hooks left in code to support later but not available yet. I've seen alot of neat displays people have done for flight simulators and driving simulators. My own 'dream' system is a planetarium dome style projector with multiple projectors to both up the brightness and resolution - however the better systems i've seen use a form of circular mirror to distort the output of a DLP projector to cover more of the dome with resolution oriented towards the middle most of the time. Such a system requires pre-warping the image. There are a few software programs out there I believe supporting such things but it's VERY expensive/not within reach of a hobbyist or weekend volunteer teacher who wants to show cool things to kids on the homebrew star projector...