Re: [LI] Attention: 3d card owners

[Shanker Balan <shanu@xxxxxxxx>]

Anand Singh Bisen wrote:
 
> nOw you are getting it !!! it's GLX.

About time i stopped speculating and did some actual research! Came
across this -

How does OpenGL, GLX, and Mesa fit into the DRI?
http://www.opengl.org/News/Special/DRI.html#Q5

And voila, everything fits in. It's actually a combination of OpenGL,
GLX, Mesa and finally the application say Quake3.

OpenGL - OpenGL is the SGI standard graphics API

GLX - GLX is the graphics library extension to X which allows OpenGL
and 	the X Window System to function together

Mesa - Mesa is an open source implementation of a very complete 3D
drawing library, which exposes a clone of the OpenGL API to applications

GLX is not absolutely necessarry for an app to use 'OpenGL hardware
accelaration'. It is reqd only for the X windows sytem to make OpenGL
API calls. If i had GNOME or KDE compiled with GL extensions, GLX would
be reqd. But I can run Quake from the console and still get hardware
accelaration by choosing the defaultGL driver because it supports GL
thru mesa libs and not via GLX. If i were to run Quake within X, then i
would choose the GLX driver.

>Yes they are all supported but the 3d part of those cards are not
>utilised the rendering is done by software not hardware.

To support my earlier comment about accelaration w/o GLX i quote from
the README.mga file:

<QUOTE>
o Makes extensive use of the graphics accelerator.  This server is very
  well accelerated, and is one of the fastest XFree86 X servers.
</QUOTE>

Any idea what accelaration we are talking here ??? Also, what happens if
i run my Xserver with option "no_accel" ???
                                                     
> Just try running Quake 3 Arena Test on your G200 or G400 or whatever
> and just try moving a 10 steps within 15 mins time, and you'll know it
> that your card is not being utilised.

I agree. Performance will be dreadfully slow because Q3A does not have
svgalib or softX rendering! An OpenGL complaint card is a must. Which is
one of the primary reason i want to get the G200.

BTW: What's the fps on timedemo ?

> Since when did i talked about GL here i think it's written GLX 

IMHO, GLX,Mesa and DRI are all OpenGL implementations! It is called
OpenGL as it has been made open source very recently by SGI.

> it a some kind of library which takes the control of rendering from X
> libs and does the hardware rendering and put's it on the screen. 

GLX = OpenGL + X ( X on steroids ;))
How can it be called hardware rendering if GLX does all the rendering?
The rendering is done by the OpenGL complaint card! 

Now with GLX, an application can either use the mesagl libs or the
Xserver GLX API. 

>(it a extension and a part of GL )

Is it an extension or is it an implementation of OpenGL,like mesa?

> nOw you are getting it !!! it's GLX.

Hmmm... If i were referring to X + OpenGL it should be called GLX. If it
is quake, i would referre to it as mesaGL. Why??? Mesa is what the Quake
engines (Q1,Q2 and Q3A) use and not GLX.

GLX,mesa and DRI are just implementations of SGI's OpenGL technology. If
it were not for OpenGL there would only be DirectX <groan> !!!

This has been a very interesting thread. Looking forward to your
comments!

--Shanu

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