[PATCH 1/2] compositor: Make sure surface->transform.matrix,inverse are always valid

[Kristian Høgsberg]

On Thu, Feb 28, 2013 at 12:27:41PM +0200, Pekka Paalanen wrote:
> On Wed, 20 Feb 2013 12:46:42 -0500
> Kristian Høgsberg <hoegsberg at gmail.com> wrote:
> 
> > On Wed, Feb 20, 2013 at 01:05:42PM +0200, Pekka Paalanen wrote:
> > > On Tue, 19 Feb 2013 17:04:50 -0500
> > > Kristian Høgsberg <krh at bitplanet.net> wrote:
> > > 
> > > > First step towards getting rid of the transform.enabled optimization.
> > > > ---
> > > >  src/compositor.c | 11 +++++++++++
> > > >  1 file changed, 11 insertions(+)
> > > > 
> > > > diff --git a/src/compositor.c b/src/compositor.c
> > > > index 64d0830..07b95a9 100644
> > > > --- a/src/compositor.c
> > > > +++ b/src/compositor.c
> > > > @@ -520,6 +520,17 @@ weston_surface_update_transform_disable(struct weston_surface *surface)
> > > >  	surface->geometry.x = roundf(surface->geometry.x);
> > > >  	surface->geometry.y = roundf(surface->geometry.y);
> > > >  
> > > > +	/* Otherwise identity matrix, but with x and y translation. */
> > > > +	surface->transform.position.matrix.type = WESTON_MATRIX_TRANSFORM_TRANSLATE;
> > > > +	surface->transform.position.matrix.d[12] = surface->geometry.x;
> > > > +	surface->transform.position.matrix.d[13] = surface->geometry.y;
> > > > +
> > > > +	surface->transform.matrix = surface->transform.position.matrix;
> > > > +
> > > > +	surface->transform.inverse.type  = WESTON_MATRIX_TRANSFORM_TRANSLATE;
> > > > +	surface->transform.inverse.d[12] = -surface->geometry.x;
> > > > +	surface->transform.inverse.d[13] = -surface->geometry.y;
> > > 
> > > I think you are missing initialization of the inverse matrix here, the
> > > other elements may be arbitrary from the previous transformation.
> > 
> > Yes, you're right.  I'll just do
> > 
> >         surface->transform.inverse = surface->transform.position.matrix;
> > 
> > instead of the inverse.type assignment and we should be good.  Nice catch.
> 
> Hi,
> 
> did you forget this fix? :-)

I did, didn't I... that's the second time you've caught that now.

Kristian