[cairo] pixman box filtering code prototype

[Aron Rubin]

Jeff Muizelaar wrote:
> It works by projecting each pixel of the destination surface to a
> parallelogram on the source surface.  All of the pixels in the
> parallelogram are summed to produce the value of the destination pixel.
> 
> I've attached a patch against pixman revision
> 6449782f8a4bea0274a30f86d56214c2c73c0303. It does not merge without
> conflicts so it will need some manual merging.
> 
> I've also attached a test program that generates the output something
> like: http://people.freedesktop.org/~jrmuizel/box-filter.png vs.  the
> existing bilinear code at:
> http://people.freedesktop.org/~jrmuizel/bilinear.png
> 
> This example isn't the best at showcasing the code because it's scaling
> down a simple image and not scaling too much, however it was a very
> useful test case for getting things correct.

Where is the source image? The large A is different in each image.

Aron