Aaron Ardiri wrote:
>
> not to be picky, but - why would one want to copy from VRAM to VRAM?
>
> if you have the adequate knowledge of the hardware, you'd just
> manually set the display address on the controller to point to
> the two VRAM chunks consecutively. :)
This was just an example emphasizing the slowness of direct VRAM. If a person was
constructing his frame in VRAM, he might want to
copy it to the new buffer (so as not to deal with 2 frame lag region deltas) using
WinScreenLock(copyScreen), or he might just be
doing something bidirectional to the one VRAM buffer like an in-place 2d scroll.
(Which I actually do to speed up text scrolling,
etc.)
>
> so, basically.. if you create your own offscreen window, and blit
> the data directly to VRAM - thats the most optimal solution without
> tweaking anything - which is what everyone does right now.
>
Well, if that's so, then I guess i didn't need to point it out. :) And I certainly
never felt that seasoned game programmers
weren't aware of this, so I really hope i didn't offend anyone on that count.
I guess i had just gotten the impression from some people's responses (no, not yours
;) to my CopyBuffer discussion that they
wouldn't be copying a buffer into VRAM -> they'd be creating the frame directly in
VRAM - and hence they'd never use my function to
copy a buffer into VRAM. Which can be faster - just not always so. So I wanted to
show them that for a scrolling game, it is worth
copying the buffer.
>
> also, in regards to VRAM, only color devices have it right now :)
> so performance tests on other Palms may prove pointless :) they
> will yield RAM -> RAM copy rates, which are a lot higher.
I'm VERY glad you pointed that out! It's excellent news, and it means I only have to
deal with all these nasty issues on 2 Palm
devices: IIIc and Prism! Finally we can get Atari ST speed out of this thing! :)
> right now, the only way to test if the
> SED 1375/6 controller exists is to read from a predefined memory
> location (0x1f00000 - from memory) and check if the value 0x24
> exists in that location
True - quite a catch 22.
> as i discussed with david fedor at palmsource europe, it woul
> be nice to have a feature made available - to tell developers
> an identification code of some form for the display controller(s)
Thank you. It will help.
>
> however, the real question is if Palm wants to venture down
> that line?? do they really care about "pushing the limit"?
> is the device supposed to be a gaming platform? those are
> the questions you need to get answers to.
There's no doubt that Palm's strength is in business and basic "I just want a good
PDA" users. But ultimately, home users will
battle it out over (perceived) entertainment value. Currently, Palm hardware really
is only competing on the lower end of the
hardware market, (i.e., light weight, small, simple, portable) and I hope that through
3rd party licenses someone will try to take
on the high end using the PalmOS. (I love the PalmOS, but when the hardware of an
iPaq (including their Microsoft Tax) can sell for
only $499 and a Prism costs $449, there's a big price inequity there.)
You probably remember, Aaron - back in the days when PCs had CGA/EGA screens and no
sound, PC users would see full screen animation
and sound on Archimedes, Ataris and Amigas and just scoff "that's a game machine!
REAL computers can't do graphics!" Now, they
judge their PCs by how good they are at games. :) Apple used to FORBID public
development of games for the Mac (image or
insecurity?) - now they use it as a sign of their market strength. (Funny given how
the Apple I was marketed as a game machine :)
I know games are a side market for Palm - but I'm willing to try to lay the foundation
now.
Who knows, Aaron - next years Palms may be powerful enough for you to write a GameBoy
Advanced Emulator! OH I would so love it if
you could have that out on the street before the first GameBoy Advanced sold in the US.
Sorry - got off topic with my fantasy, there.
Cheers!
- jeff
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