rendercheck: background should be cleared when drawing trapezoids.

[Søren Sandmann]

Vikram Fugro <vfugro at nvidia.com> writes:

> Hi all,
>
> With the recent pixman library, trapezoid drawing on background has been fixed 
> by clearing the background (instead of retaining the color of the background).
>
> I have done the necessary changes in the triangles use case (in rendercheck) 
> for the "color expected" from the background. 
>
> Attaching the patch and the snapshots for reference.

Reviewed-by: Søren Sandmann <ssp at redhat.com>

See also

    http://lists.freedesktop.org/archives/pixman/2013-April/002755.html

for some rationale for the change in pixman.


Søren