Qtopia coming for Neo1973

[Lorn Potter]

Dr. H. Nikolaus Schaller wrote:
> 
> Am 25.09.2007 um 17:20 schrieb Dani Anon:
> 
>> But hey I like how you conveniently left unanswered my comment about
>> how the FBUI and DirectFB projects exist solely to remove the X server
>> overhead. Can you explain to me and them why they are wrong and how
>> they have wasted all those months of development to solve a problem
>> that just doesn't exist?
> 
> It exists theoretically but the practical relevance depends on several 
> factors.
> 
> I have done some experiments on the OpenMoko and I believe that the
> framebuffer itself is the slowest part (don't know why). But X11 *is* 
> already
> quite fast.
> 
> I could achieve a lot of speed up in my GUI Framework (yes it is another 
> choice!)
> by double buffering X11 (i.e. drawing offscreen first and then copying the
> modified block in a single bitmap copy command).
> 
> In my GUI toolkit the main speed killer is the missing FPU in ARM 
> processors
> which has to rely on FPU emulation.
> 
> So, why optimize something that already works sufficiently? It is like 
> washing whiter
> than white. But if there is someone who wants to optimize it further - 
> why not?
> 
> So - IMHO - the X11-Overhead is a neglectable problem. And the benefits 
> of X11
> overweight any drawbacks.

There may not be very much performance differences, but there is one 
more drawback of using Xlibs. File size and memory.


-- 
Lorn 'ljp' Potter
Software Engineer, Systems Group, MES, Trolltech