surface buffer cardinality and outputs

[Jerome Glisse]

On Wed, Mar 20, 2013 at 4:32 AM, RenoX <renozyx at gmail.com> wrote:
>
>
> On Tue, Mar 19, 2013 at 11:34 AM, Jason Ekstrand <jason at jlekstrand.net>
> wrote:
>> I'm not sure exactly what I think of all this surface transform
>> passing.  I'll get back to that once I get a chance to think about it.
>>  Part of the problem is that you don't want to try and make your
>> animations subpixel-perfect because that would require a lot of
>> round-trips to make it right.
>
> And you(Jerome Glisse) replied:
>> It doesn't add more roundtrip, client will get next matrix like a
>> frame event, client then draw in screen space and then draw with new
>> transformation matrix. If client can't keep up it wouldn't either keep
>> up in the non screen space rendering case.
>
> I disagree: currently Weston move windows server side only, that is to say
> without roundtrip,
> if you want to be 'subpixel perfect' then moving a window imply to re-render
> it from the client, which will add a lot of roundtrip in this case.
>
> So the current design is 'pixel perfect', but not 'subpixel perfect', and
> cannot be without big changes..
>
> regards,
> renoX

What i propose is an extension ie application can still render non
subpixel and can still render non subpixel when moving/resizing. Note
also that moving a window around is not so much different then
resizing a window in which case wayland will round trip with the
client. So really if a client want subpixel rendering at all time it
just add roundtrip in the window is moving case.

Again i stress it's not a lot of roundtrip it's the same amount of
roundtrip as with resize window.

Change i propose are not big, it's a fairly small contained change, i
will try to hack something over the weekend.

Cheers,
Jerome