[rescue] "bloated pig X11"

Meelis Roos mroos at linux.ee
Thu Aug 9 07:49:23 CDT 2012

> You just reminded me of something.  With the current talk about replacing X11
> with something better, I was wondering why there doesn't seem to be talk about
> reintroducing something similar to NeWS / Display Postscript. Wayland is
> interesting, but as far as I'm concerned, it's a non-starter as long as they
> keep network transparency out of the spec.

Todays requirements are different because the hardware is vastly 
different and usage patterns shift quickly to make use of the new 

Graphics cards of X11 design era were not safe to use by multiple 
applications simultaneously (or no direct access at all) so a mediator 
was needed (graphics server), memory access was cheap but CPU and 
graphics cards were the bottlenecks. So X server along with some 
inter-process communication was a good engineering decision.

Today we have (3D) vector capable graphics cards that emulate the 2D 
part using 3D engine, multiple applications can use the card without 
lockup or isolation problems. Basically we have a DMA pipeline to the 
card, using IRQ-s for flow control. We can mostly take the DMA pipeline 
directly to the applications using a thin kernel driver and userspace 
library, and do the acceleration stuff in another userspace library. No 
need for graphics server because of IPC latency and memory latency of 
passing data and control.

Thus the gradual migration to clever clientside libraries that can make 
use of vector API-s directly when the time comes.

So DPS would need to be interpreted in the application itself and would 
be a userspace API. For a protocol, it might have been OK but as an API 
it probably would not be worth much.

Also, current drawing models use vector and transparency (the "PDF" 
model), Postscript can use vector well but lacks transparency and has 
opaque colors only (can not use the full capabilities of the graphics 
cards). Not that transparency is worth much in any static image that you 
stare (more strain to the brain to interpret it) but it has its uses to 
make some transitions more intuitive.

Meelis Roos (mroos at linux.ee)

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