[Pixman] [PATCH 1/4] Change conditions for setting FAST_PATH_SAMPLES_COVER_CLIP flags

[Ben Avison]

On Wed, 16 Sep 2015 03:09:50 +0100, Søren Sandmann <soren.sandmann at gmail.com> wrote:
> If all existing fast paths and iterators can be
> changed/verified to not read outside their bounds, I have no objection
> to changing the meaning of the existing flag (or adding a new one if
> that's more convenient).

OK, it sounds like the way to go is use two flags for at least a
transitional period. Then if and when all fast paths and iterators are
changed, then we can delete the old flag.

> I realized that there is another use for a new flag like this: It could
> likely also be used here:
>
>     http://cgit.freedesktop.org/pixman/tree/pixman/pixman.c#n662
>
> so that images would be considered opaque in more cases, leading to more
> cases of reducing the operator from OVER to SRC.

I had come across that when searching the source code for references to
the COVER_CLIP flags, but had mentally filed it away because I wasn't
sure at which point it would be appropriate to switch it over to using
the new bilinear flag. But having thought about it a bit more, I agree it
could use the new definition straight away, even before any fast paths or
iterators do.

Ben