It is _possible_ to do it this way: witness the "Backdrop" program that
puts a background image on the screen. If you looked at all the traps it
patches, you'd be amazed!
..might also be possible to flip some hardware register...you'd have to
look.
---
--On Thu, Jun 24, 1999 5:07 PM +0200 Aaron Ardiri <[EMAIL PROTECTED]> wrote:
> On Thu, 24 Jun 1999, Bobby Kolev wrote:
>>
>> I've asked the same question several months ago and nobody did.
>> Then, I read the display specification and I do not think it is possible
>> as a quick patch - the screen can be flipped by the X axis relatively
>> easy, but nothing about the Y axis.
>>
>> I was thinking of doing it as a hack, but after reviewing the pros and
>> cons I thought it would be too hard and slow and canceled it.
>>
>> if you want to keep using the OS API and have it flipped, I guess the
>> best place to do it is somewhere _inside_ ROM functions - as low as
>> possible.
>
> this would be the "tedious" way to do it.. but how about doing in your
> software? just imagine all the ROM calls you would need to catch!? :(
> - the best way would be for palm to have a routine called
>
> Void WinFlipScreen(DirectionType direction)
>
> but.. if you want to try it.. try this for a theoretical point of view:
>
> use a backscreen image, and draw to it as normal, then.. when you
> want to display it.. reverse the contents of the "pixel array".
> (dont know how it will be affected based on display modes).. but
> in theory.. it would work?
>
> if you want to know how to do a backscreen image, then have a look
> at the Cube3D source code located here:
>
> http://www.hig.se/~ardiri/development/palmIII/index.html
>
> i use gcc environment - but this should not matter for the double
> buffering code.
>
> cheers.
>
> az.
> --
> Aaron Ardiri
> Lecturer http://www.hig.se/~ardiri/
> University-College i G�vle mailto:[EMAIL PROTECTED]
> SE 801 76 G�vle SWEDEN
> Tel: +46 26 64 87 38 Fax: +46 26 64 87 88
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>
