[cairo] [cairo-commit] src/cairo-quartz-surface.c

Baz brian.ewins at gmail.com
Sun Nov 18 14:24:40 PST 2007


On Nov 18, 2007 8:52 PM, Behdad Esfahbod <behdad at behdad.org> wrote:
> On Sun, 2007-11-18 at 15:32 -0500, Brian Ewins wrote:
> >     [quartz] zero memory on bitmap creation
>
> Hi Brian,
>
> I don't think other backends do this, do they?  Can you elaborate?
>
> Thanks
>

cairo_image_surface_create does:

"Initially the surface contents are all 0. (Specifically, within each
pixel, each color or alpha channel belonging to format will be 0. The
contents of bits within a pixel, but not belonging to the given format
are undefined)."

There's a calloc in pixman causing this behaviour. I havent
investigated why the rest of the surfaces aren't failing these tests -
what's going on appears to be that when the second 'similar' test is
run for each of the 7 failures I had, a push-group is done to create
the similar surface before the test is run, and these tests use a
transparent background fill instead of solid white, so that the
pop_group shows the background corruption.

I'd be happy to revert and fix the test instead if you prefer. Vlad
was surprised that the documented behaviour for the image surface was
still that way.

Cheers,
Baz


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