[cairo] Possible A8 Compositing Bug

[Chris Wilson]

On Fri, 17 Sep 2010 13:38:16 -0400, Jeremy Moles <jeremy at emperorlinux.com> wrote:
> I have attached a very small C application (~15 lines of code)
> demonstrating what I believe to be a bug in CAIRO_FORMAT_A8 when using
> the CLEAR operator. It only appears to be clearing those areas in DEST
> where SRC's alpha isn't full intensity (if that terminology makes any
> sense :)).

Sorry for the delay. I've added your test case:

commit 05faebd5845c68005f5b96428952faae5a67208f
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Wed Sep 29 13:23:24 2010 +0100

    test: Add a8-clear
    
    Reported-by: Jeremy Moles <jeremy at emperorlinux.com>
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

and the fix:

commit 66ace8cd33c0ebe88972f0c4d5c0effeacb1cea3
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Wed Sep 29 13:46:02 2010 +0100

    image: The a8 in-place span compositing is only valid for SOURCE
    
    Fixes test/a8-clear.
    
    Reported-by: Jeremy Moles <jeremy at emperorlinux.com>
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

Many thanks!
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre