Weekly edition	Kernel	Security	Distributions	Contact Us	Search
Archives	Calendar	Subscribe	Write for LWN	LWN.net FAQ	Sponsors

Wayland the "successor" LCA: The X-men speak

Posted Feb 14, 2013 13:56 UTC (Thu) by Cyberax (✭ supporter ✭, #52523)
In reply to: Wayland the "successor" LCA: The X-men speak by Serge
Parent article: LCA: The X-men speak

It's definitely not "better in every aspect". DirectFB is a very lightweight X-server look-alike moved into the kernel. It has no real support for running OpenGL applications and can only do simple compositions.

(Log in to post comments)

Posted Feb 14, 2013 19:15 UTC (Thu) by Serge (guest, #84957) [Link]

> It's definitely not "better in every aspect".

Maybe. :) But it's not that obvious.

> DirectFB is a very lightweight X-server look-alike moved into the kernel.

It does not require kernel patches. It only builds a fusion kernel module for fast IPC. And it's much farther from X-server than Wayland.

> It has no real support for running OpenGL applications

DirectFBGL? You can see some 3D-looking samples in http://ilixi.org/ video.

> and can only do simple compositions.

Weston can also do simple compositions. It's up to the compositor, I guess.

Wayland the "successor" LCA: The X-men speak

Posted Feb 14, 2013 19:25 UTC (Thu) by Cyberax (✭ supporter ✭, #52523) [Link]

I had been watching DirectFB development very close back in early 2000-s. As far as I remember:
1) It uses Linux FB support for modesetting. So no multiple monitors, rotation, etc.
2) It has its own input stack.
3) It required custom kernel modules and direct hardware access from the userspace (ugh).

I don't remember it ever trying to support OpenGL, but I guess that blitting from a texture to framebuffer is not that complex to add if you have a working EGL.

In short, DirectFB is more like a classic framebuffer with several hardware accelerated operations. It's not nearly enough for modern graphics.