[cairo] Xlib/Xcb and EXTEND_PAD

[Zack Weinberg]

Thomas Jaeger <thjaeger at gmail.com> wrote:

> I just looked at the source of all the video drivers that are
> currently in Ubuntu jaunty.  There are 7 drivers that accelerate
> Composite in one form or another.  Except for the intel driver, none
> of them even access the repeatType field, so it's not much of a
> surprise that we get bad results.

Thanks for this list.

I also noticed bad behavior with non-nearest-neighbor scaling
independent of the Repeat mode.  I don't have a test program for it,
but no matter what the scaling mode is, if you scale up a 1x1 surface
to MxN, all of the pixels of the result ought to be *exactly* the same
color as the original pixel.  This is not true for the ATI drivers in
bilinear mode; you have to scale to like 500x1 to see it, but some
fraction of the pixels will be slightly off (invisible to the eye, you
have to look at the color histogram).

Do you have contacts with the X video team(s)?  Are you able to pursue
these driver bugs and get them fixed?

zw