[Scummvm-devel] Strange problem with ARM 2x scaler in WinCE port

[Ismail Khatib]

Hi all!

Yesterday I checked a problem in the WinCE port which was reported in
the forums, and after I changed the scaler in my testconfig to 2x (was
using HQ2x before) I could reproduce it. It doesn't occur when the
aspect correction is enabled. I could track down the problem to the file
graphics/scaler.cpp; when I change line 180 (#ifdef USE_ARM_SCALER_ASM)
to "#if 0" for example, to disable only this Normal2xARM scaler,
everything works perfectly, so I assume the problem really lies inside
graphics/scaler/Normal2xARM.s (but I'm not really sure about this, it
could also be in graphics/scaler/scalebit.cpp, but hadn't enough time
yesterday to check where exactly the problem lies.

It seems that there is some problem with refreshing/clearing AFAICS...

Here some screenshots to explain what goes wrong (Space Quest III Intro
& first game screen):
http://img36.imageshack.us/img36/1899/screen01yl.jpg
http://img98.imageshack.us/img98/715/screen02vb.jpg
http://img62.imageshack.us/img62/870/screen03w.jpg
http://img853.imageshack.us/img853/2981/screen04a.jpg
http://img854.imageshack.us/img854/1718/screen05o.jpg

My question now is (escpecially to other ARM porters):
Do you have similar problems when using this scaler on your platform? My
understanding is, that this problem should occur on all ARM platform
which are using this scaler (I think the DS is out because it hasn't got
a > 640x480 display, but still maybe Android or iOS)?
And does anyone has an idea on how to fix this?

Thanks in advance!

Regards,
Cerial