[RFC] wl_surface scale and crop protocol extension

[Daniel Stone]

Hi,

On 2 May 2013 19:06, Bill Spitzak <spitzak at gmail.com> wrote:
> Pekka Paalanen wrote:
>> So it's really a question whether we can require all compositors to
>> unconditionally support crop&scale. And that really means *all* Wayland
>> compositors forever, since wl_surface is core protocol.
>
> I see no reason not to make this a requirement. You already require 90
> degree rotations and ortogonal reflections (since clients can set the buffer
> transform) and weston uses arbitrary transforms to rotate windows. And you
> require ARGB32 support even if the hardware does not like it.
>
> I also think all of wl_shell should be a core requirement.

Not all compositors are user sessions.  Think about nested compositors
for browsers, or capture, or also very stripped-down usecases where
they really don't want to have to deal with this kind of thing.

I don't think it's an unreasonable requirement, and really like the
design it has at the moment, where attaching the scaler object
suppresses the resize-on-attach behaviour, and destroying it reverts
to previous.  It's pretty elegant, and totally in the vein of
wl_shell_surface stacking on top of wl_surface.  I don't see how
inventing more elaborate extension mechanisms on top of our existing
extension mechanism helps anything.

Cheers,
Daniel