[Mesa-dev] Gallium pixel formats on big-endian

Jose Fonseca jfonseca at vmware.com
Wed Jan 30 06:12:05 PST 2013

----- Original Message -----
> On Mon, 2013-01-28 at 06:56 -0500, Adam Jackson wrote:
> > I've been looking at untangling the pixel format code for
> > big-endian.
> > My current theory is that blindly byte-swapping values is just
> > wrong.
> Certainly. :) I think you're discovering that this hasn't really been
> thought through beyond what's necessary for things to work with
> little
> endian CPU and GPU. Any code there is for dealing with big endian
> CPUs
> has been bolted on as an afterthought.

My memory is a bit fuzzy, but I thought that we decided that gallium formats were always defined in terms of little-endian, which is why all need to be byte-swapped. The state tracker was the one responsible to translate endian-neutral API formats into the non-neutral gallium ones.

Anyway, I'd suggest searching and summarizing the 2-3 threads we had about this on the mailing lists.

And once we make a decision, we should update src/gallium/docs/ to be crystal clear. (Although there was interest, there was never an ongoing commitment to get big-endian platforms running well before, which is why this stuff hasn't been fully iron out yet.)


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