[cairo] Better quality downsampling in cairo/pixman

[Alexander Shulgin]

On Fri, Aug 13, 2010 at 21:00, Owen Taylor <otaylor at redhat.com> wrote:
> On Tue, 2010-06-29 at 10:04 +0300, Alexander Shulgin wrote:
>
>> The other day I was using Alt+TAB to switch between windows in my
>> brand new Ubuntu desktop and was unpleasantly surprised how window
>> thumbnails quality was in striking contrast with the overall eye-candy
>> of the desktop (other effects seem to use OpenGL).
>
> I think pixman and cairo are pretty irrelevant for this. Window
> downscaling for previews needs to:
>
>  A) Leave the images in video memory
>  B) Be fast and hardware accelerated
>
> The basic way that GPU's sample images is bilinear sampling. As we see
> with Cairo currently, that doesn't work nicely once you are scaling down
> more than a factor of two.

Thanks for your comment, Owen.

Unfortunately, I'm still too busy with other things (i.e. life).  Only
if I could convince my employer to give me some time to work on this
(as we use a backwards hack to overcome the downscaling problems
currently)...

OTOH, I see Krzysztof has taken this problem more seriously than I
did, so there's hope for some progress soon--thanks, Krzysztof!

--
Alex