[Pixman] sRGB processing for pixman
Søren Sandmann
sandmann at cs.au.dk
Mon Jun 25 10:47:29 PDT 2012
Bill Spitzak <spitzak at gmail.com> writes:
> A problem is the pseudo-random starting point. This is necessary so
> that you do not get vertical stripes when the rows have the same
> data. But if you want your composites to not change, it has to be
> deterministic. I'm not sure but perhaps a hash of the y coordinate of
> the source will work, or that hash plus the color of a pixel at x==0.
Error diffusion is a good idea in principle, but the problem you
describe above is quite tricky to deal with. A hash of the source y
coordinate won't work in the case where the source is a solid color and
the coordinates are simply (0, 0). A hash of the destination y
coordinate is not going to work either, because it would cause stripes
when scrolling.
I think we just need to fix the bug and make the transformed paths use
the wide pipeline when wide formats are involved.
Søren
More information about the Pixman
mailing list