[maemo-developers] [maemo-developers] 800x480

From: Aleksandr Koltsoff czr770 at iohazard.tts.fi
Date: Mon May 30 08:25:55 EEST 2005
On Saturday 28 May 2005 22:46, Asko Kauppi wrote:
> Ability to swap horizontal/vertical (at least in full screen mode)
> would be an almost must-have for this device.  I know SDL could do
> it, at some level, but there are issues s.a. blitting images on the
> screen that might be more elaborate.
> Has there been discussion/plans upon this?  Best of all: ability to
> sensor current physical orientation, and adopt instantaniously.

Hello ak :-),

At least I know that the AF get's a bit flaky if its screen resolution is 
anything else than 800x480 (like 480x800). So I think (note I haven't seen 
770 myself) that providing Xrandr would be limited (currently) to fullscreen 
applications that could use it, but the application should switch back to the 
"natural" orientation on exit. I don't know whether the AF will be fixed to 
handle that situation. Although screen space will be quite limited for 
usability in the other orientation as it is. Also the on-screen keyboard 
might get somewhat confused, as well as the hand-writing recognition.

As for SDL, it's pretty simple since it can fake the screen orientation. The 
problem will be with a rotational transform when "blitting" (the 770 doesn't 
have a graphics processor). So this would make sw based blitting quite slow 
as for each copied rect area, the access pattern would be left->right 
(top->bottom) instead of the normal top->bottom (left->right) and I would 
imagine that the memory bus is not optimized to handle wide strides like 
this. This might be how X does Xrandr as well, but it has the advantage of 
having Xrender (on some platforms) which can do the rotation in hardware so 
in those cases it's not an issue.

Please correct me if I'm wrong, I haven't read Kdrive/Xrandr-sources.


More information about the maemo-developers mailing list