PI Releases DRI to XF86

Frank LaMonica of Precision Insight wrote in to say that they have released the code to their Direct Rendering Infrastructure to the XF86 project. I saw this thing in action at LinuxExpo- very smooth quakin' going on. This is a great step in the right direction of having a fast standard 3D desktop under X. Works with Mesa's GL, and SGIs GLX.

Comments

Re:What about GGI/KGI?

[Izaak]

I don't understand what this 'waste of resources' is, running X to access 3D acceleration for full-screen games. Certainly it's true that the full power of X is not going to be used in this situation, but the DRI that Precision Insight (thanks!) has released will impose almost zero (or maybe exactly zero) overhead on the application once it is running.

My experience has been that X does impose a small performance hit on 3d rendering. This may just be the specific driver implementations and not something inherent in X, I don't know for certain. I do suspect that the network transparent nature of X, while adding wonderful flexibility, sacrifices some of the speed you can get by having an API that talks directly to the metal. I'll need to learn more about PI's DRI before I form an oppinion.

My main gripe, however, is with the memory that X soaks up, especially when you are running a decent window manager and/or desktop environment. Not a big deal if you are running latest and greates hardware, but I would like to write games that scale down to older hardware.

From a philosophical standpoint, I think graphics acceleration should be handled with an abstraction layer / API that sits right on top the hardware and then the windowing system sits on top of that. Graphics can then be accessed by both X and non-X apps.

GGI does this, and in fact goes a step farther. X itself can be used as a visual target by GGI apps. GGI can sit both under and on top of X, and apps transparently figure out what enviroment they are running in. When I run my game engine, for example, GGI automatically figures out if I am in X windows or on the console and loads the correct visual target automatically. I did not have to write code for this, it is a built in part of GGI's functionality.

I guess what I am saying here is that, from an architectural standpoint, GGI rocks. It is designed to be very portable and flexible. Writing GGI apps is a breeze (much easier than DirectX in my oppinion). I encourage anyone writing highly graphical apps (such as games) to check it out.

Thad