[PATCH] dix: set the device transformation matrix

[Peter Hutterer]

Keith, 

please merge this patch, I don't have anything else yet and this
one is a pain, particularly for users of QEMU.

On Thu, Sep 20, 2012 at 08:59:53AM -0700, Chase Douglas wrote:
> On Wed, Sep 19, 2012 at 12:56 PM, Peter Hutterer
> <peter.hutterer at who-t.net> wrote:
> > The property handler is registered after setting the property, so
> > dev->transform remains as all-zeros. That causes pixman_f_transform_invert()
> > to fail (in transformAbsolute()) and invert remains as garbage. This
> > may then cause a cursor jump to 0,0.
> >
> > Since the axes are not yet initialized here and we need to allow for drivers
> > changing the matrix, we cannot use the property handler for matrix
> > initialization, essentially duplicating the code.
> >
> > Triggered by the fix to (#49347) in 749a593e49adccdf1225be28a521412ec85333f4
> >
> > https://bugzilla.redhat.com/show_bug.cgi?id=852841
> >
> > Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> > ---
> >  dix/devices.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/dix/devices.c b/dix/devices.c
> > index 46c759c..77fde80 100644
> > --- a/dix/devices.c
> > +++ b/dix/devices.c
> > @@ -306,6 +306,9 @@ AddInputDevice(ClientPtr client, DeviceProc deviceProc, Bool autoStart)
> >      /* unity matrix */
> >      memset(transform, 0, sizeof(transform));
> >      transform[0] = transform[4] = transform[8] = 1.0f;
> > +    dev->transform.m[0][0] = 1.0;
> > +    dev->transform.m[1][1] = 1.0;
> > +    dev->transform.m[2][2] = 1.0;
> >
> >      XIChangeDeviceProperty(dev, XIGetKnownProperty(XI_PROP_TRANSFORM),
> >                             XIGetKnownProperty(XATOM_FLOAT), 32,
> 
> Makes sense to me.
> 
> Reviewed-by: Chase Douglas <chase.douglas at ubuntu.com>