X, directfb, svgalib, dri, glx, help?

DevSolar · Tux's lil' helper Joined: 07 Sep 2004 Posts: 82

My understanding of the graphics subsystem(s) of Linux is still rather fuzzy around the edges...

X is understood, I think. But numerous other packages and kernel options are flung at me - directfb, svgalib, drm, dri, glx, opengl, ... - and I can't really sort out what I would want / need and what not.

"make menuconfig" mentions XFree86 (was it in the DRI options?), but no word is lost on whether X.org X11 does support the same interface - that doesn't help either.

I want a console that offers more than 80x25 characters... but the "make menuconfig" does not offer me framebuffer drivers for the nVidia FX 5200 I use - I understood I need framebuffer to do anything beyond BIOS?

I am severely confused... Can someone point me to a summary on these things, so I can make educated decisions?

Oxyron · Posted: Wed Sep 29, 2004 11:49 am Post subject:

I don't know if these are right, please correct me if i'm wrong.

SVGAlib - display library helping programs use framebuffer
DirectFB - similar to SVGAlib, but faster, with video acceleration
DRM,DRI - something to do with direct rendering
OpenGL - opensource 3D graphics library
GLX - something to do with OpenGL and X

For the framebuffer in console, you should select the VESA driver in menuconfig.

DevSolar · Tux's lil' helper Joined: 07 Sep 2004 Posts: 82

So, let's see what I figured so far:

Framebuffer is some way to access graphics hardware (technically). It has nothing to do with "acceleration" of any kind. DirectFB is one library for doing this, SVGAlib is another.

I've caught up somewhere that there might be issues when using framebuffer in parallel with X Window?

DRM and DRI are two seperate technologies, supported by ... and ... respectively?

OpenGL is a 3D library that accesses the hardware through ...? (Does OpenGL use X primitives, does X use OpenGL primitives, does OpenGL use 3D acceleration, ...?)

GLX is "something to do with OpenGL and X".

Hm... I think I need more input... help?

DevSolar · Tux's lil' helper Joined: 07 Sep 2004 Posts: 82

*bump*

Come on, someone must know what he/she's installing...

Stormy Eyes · Posted: Wed Sep 29, 2004 2:22 pm Post subject:

DevSolar · Tux's lil' helper Joined: 07 Sep 2004 Posts: 82

OK, figures so far.

Still no info on what dri, drm, glx, svgalib, directfb et al. are about, and why I could want to install them?

I want nothing out of the ordinary - a X desktop that makes full use of the available hardware (i.e., 3D acceleration if available), without adding lots of useless stuff that might be meant for non-X environments or, worse yet, collide with each other.

When I made that first posting, I fully expected to be pointed towards some oft-quoted FAQ... I can't believe this ain't "frequently asked"?

Zarhan · Veteran Joined: 27 Feb 2004 Posts: 1016

DevSolar · Tux's lil' helper Joined: 07 Sep 2004 Posts: 82

Ah, now the picture becomes much clearer. Thank you!

Now, when I sift through the USE flags list...

X, opengl, directfb and svga are pretty clear now.

But two flags still have me confused:

"dga" - Adds DGA Support (Xfree86) (DGA=Direct Graphic Access)

I found that this is supposed "to allow direct access to the framebuffer, circumventing the X11 server". From what I gather this is for video playback? Is it XFree86-specific, or can this be used with X.org X11, too?

"sdl" - Adds support for Simple Direct Layer (media library)

From what I found on the web, this sounds a bit like DirectX, right?