nanogui: Ways to speed up a simple application?
Subject:
Re: [nanogui] Ways to speed up a simple application?
From:
"Ricardo P. Jasinski" ####@####.####
Date:
17 Mar 2009 18:16:28 -0000
Message-Id: <ee9633130903171115p72b9c0f0kc7e74271dc4dd125@mail.gmail.com>
Thanks for the nice introduction, this is more than I could ask for!
Since we are apparently working on similar platforms, I would like to
ask you a few more questions if you don't mind...
- this so-called "card memory", should it necessarily be implemented
with embedded ram blocks available inside the FPGA?
- 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)
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, 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.
Thanks again,
Ricardo.
>> I wish I knew more about this whole "blit" thing, ...
>
> This is easy :-) .
> AFAIK, with "accelerated" graphics you distinguish between processor-memory-based and "card"-based memory. The CPU only can access the processor memory directly, but the card memory is behind some driver using the card's hardware interface and that makes access by the processor very slow, but allows very fast access by any graphic hardware function. Bitmaps can be either in the processor memory or in the card memory. If they are in the card memory, they can either be "on screen" (visible) or "off-screen" (invisible).
>
> The "bilt" functions the driver provides now copy a bitmap (rectangle) from one memory location onto another, using the processor if only processor memory is involved, using some hardware "processor" on the card, if only card-memory is involved and using the driver hardware-interface if both are involved.
>
> -Michael
>
--
-------------------------------------------------------
Ricardo Pereira Jasinski
####@####.####
Tel: (41) 9955-2852
LME - Laboratório de Microeletrônica da UTFPR
UTFPR Microelectronics Lab
www.lme.cpdtt.cefetpr.br
Tel: +55 41 3310 4756
