Just a warning - Aaron you might have experienced this little irony...
On that Palm IIIc, at least, using movem code direct to the screen can be TOO FAST.
If you use Afterburner AT ALL, and push the CPU about 20 MHz, your movem code
disintigrates because you exceeed the 1 meg/second
limit of the Epson 1375. Reading is even worse.
So, ironic as it is, I had to make a version of my code to NOT do fast copies if
Afterburner is enabled.
The maker of Afterburner was telling me that the real key to Palm programming is to
SLOW DOWN the screen access by interleaving
useful instructions with the instructions that BLiT to the screen.
Ahhh.... the irony of it all. Optimization is a many headed beast. :)
But just to emphasize, if the person is running at 20 MHz or less, movem is slow
enough for the screen to handle.
Unfortunately, I have no experience on the regular Palm's yet to find out the upper
limit of their graphics buses, but given that
the LCD bus width is only 1/4 that of the memory bus, and given that the
Dragonball-only LCD controller accesses main memory for its
data, I bet there's an upper speed limit there as well. :)
Aaron Ardiri wrote:
> > If you need some exemples, look at the interresting sources of Aaron Ardiri.
> > ( http://www.ardiri.com, but who doesn't know ? :)
>
> keep in mind.. if you do this type of code, then CHECK the CPU before
> you do so.. this optimized code can be emulated on an ARM machine,
> however - it worked best on a m68k :)
>
> also, the sample code writes directly to the screen. dont just copy
> that code, be sure to use the API calls if you are unsure about the
> circumstances you'll be dealing with when copying to the screen
> buffer..
>
> the Cube3D demo for example, did not work on the ARM prototype
> machine at PalmSource at first - the endian of the data is different,
> so garbage was displayed on the screen. check your CPU and device
> before you make any assumptions.
>
> :)
>
> // az
> [EMAIL PROTECTED]
> http://www.ardiri.com/ <--- free games!
>
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