[RFC] Randr 1.3 feature - get property

[Jesse Barnes]

On Monday, March 10, 2008 9:42 am Jesse Barnes wrote:
> On Monday, March 10, 2008 3:40 am Matthias Hopf wrote:
> > On Mar 07, 08 20:16:34 +0200, Daniel Stone wrote:
> > > On Fri, Mar 07, 2008 at 09:37:56AM -0800, Jesse Barnes wrote:
> > > > On Friday, March 07, 2008 3:38 am Matthias Hopf wrote:
> > > > > Isn't this again changing the ABI?
> > > > > Note that I don't have a better idea, except adding the version
> > > > > number further down in the struct, which of course is a bit
> > > > > cumbersome...
> > > >
> > > > Yeah, but we're changing ABI anyway in this release, so I figured it
> > > > was ok to break it as long as I'm adding a way to deal with breakage
> > > > later on...
> >
> > As long as the driver has an easy way to fall back to an older version
> > (if run with an older Xserver), I'm fine. I just want to avoid the
> > horror of the XVideo change, where the only way to find out the change
> > was with an elaborated autoconf macro...
> >
> > Well, there's RANDR_13_INTERFACE, so at least on compile time it's easy.
> > But I'd like to have an easy way to detect this on run time, though I
> > don't see a way to do this with the current interface.  Know that having
> > a way to this doesn't mean a driver has to do it.
> >
> > One possible way would be to let xf86CrtcScreenInit() return the version
> > number instead of a Bool. That would even be backward compatible.
>
> I'd be ok with that, do you want to hack up the change or should I?  The
> driver changes should be pretty trivial...

Actually, you should be able to use sizeof(crtc struct) as a check now that 
we've changed it.  And going forward you can just check crtc->version.

Jesse