nanogui: Ways to speed up a simple application?
Subject:
Re: [nanogui] Ways to speed up a simple application?
From:
Michael Schnell ####@####.####
Date:
18 Mar 2009 15:02:27 -0000
Message-Id: <49C10CC0.5000509@lumino.de>
> - this so-called "card memory", should it necessarily be implemented
> with embedded ram blocks available inside the FPGA?
>
Yep the "card electronic" would be implemented by means of the FPGA
("card"-memory (external or internal), graphic processor (e.g. doing the
"card"-internal blitting), interface to the processor-bus (sending
commands to the "card"-processor and moving bitmaps into the "card").
> - wouldn't we achieve similar results by instantiating a
> tightly-coupled data memory and placing the crucial bitmaps/fonts in
> it? (I'm not experienced enough to know what this change might
> involve, though)
>
Do you think you have enough FPGA-internal memory for that ? Moreover a
main advantage of the "card" processor is that it can run in parallel
with the main processor. Moreover I suppose (I'm not an expert) that
with accelerated graphic cards, the display is done in realtime: e.g.
there are multiple "on-screen" bitmaps (might even be characters) that
are used when the "scan" output bit stream is generated. There is no
single memory that represents the actual content of the screen. So
moving a rectangle around is just setting the location and not copying
any data.
> Since this hardware acceleration approach is starting to seem more
> complicated than I'd have wished (i.e., involves more than a little
> hardware and drivers tweaking), I think I will try other alternatives
> before I get back to this path,
I'm with you here ;)
> but anyway I'd be really interested in
> hearing your opinion about how we could take advantage of the FPGA in
> order to speed things up a bit.
>
Maybe you can find a special (quite simple) way of limited hardware
acceleration. I seem to remember that the interface to the hardware
driver of an accelerated card provides a "capacities" information to the
X-server and same is only free to use just those that are provided (e.g.
"none" with a not accelerated framebuffer device). Maybe there are some
"capacities" that quite easily can be done in hardware and could help
greatly.
Happy hunting. Please let us know what you find.
-Michael
