[cairo] broken pixman bilinear filtering?

[Vladimir Vukicevic]

On 2/13/06, Bertram Felgenhauer <bertram.felgenhauer at googlemail.com> wrote:
> Vladimir Vukicevic wrote:
> > The attached test produces a png like the attached output; the first
> > square is the 3x3 image scaled up 20x with bilinear filtering, and the
> > second is the image scaled up with nearest neighbour.  It looks like
> > for bilinear the center of the coverage region for the pixel at source
> > 0,0 is placed at 0,0 in the destination, when instead it should be
> > offset by half the size of the destination area covered by a single
> > pixel.
> >
> > I don't dare delve into pixman myself to look into this, I don't think :)
>
> the patch at https://bugs.freedesktop.org/show_bug.cgi?id=2488 should
> fix that. (the attached picture was created using it)

Ah, great!  I didn't think to check bugzilla first, I should have.  I
notice that this bug exists in the latest version of fbcompose in the
X server as well; this is unfortunate, as the patch was posted well
before xorg 6.9 shipped =/  Keith (or davidr?  I'm not sure who's
maintaining pixman/fb at the moemnt) should probably take a look at
the patch and integrate it..

    - Vlad