[Mesa-dev] [PATCH 03/19] gallium: make pipe_box signed in order to represent flipped blits

[Marek Olšák]

On Fri, Aug 10, 2012 at 1:42 AM, Roland Scheidegger <sroland at vmware.com> wrote:
> Am 10.08.2012 00:37, schrieb Marek Olšák:
>> I'd like to have either signed pipe_box or a new struct for that purpose.
> It looks to me like conceptually what you want is more like a coordinate
> pair. I dunno though but negative width/height/depth just aren't very
> intuitive for a box. But maybe I'm the only one caring about that style :-).

To me, both representations are equivalent because:
x1 + width = x2 (x1 is inclusive, while x2 is exclusive)

We could add checks into Galahad to make sure that pipe_box isn't
negative when it shouldn't be. IIRC, Jose said he planned to enable
Galahad by default on debug builds.

Marek