[Mesa-dev] rgtc signed format and u_format: some open questions

[Dave Airlie]

On Fri, Mar 4, 2011 at 8:17 AM, Jose Fonseca <jfonseca at vmware.com> wrote:
> About a), one day we should have this in a library shared by mesa/gallium, but until then anywhere is fine by me.
>
> About b) please provide unorm8 support for all formats. It's useful for debugging/displaying, e.g., writing to BMP files, or visualizing on a window. There is already a helper function called util_format_fits_rgba8unorm (or something like that) to determine whether a format can be faithfully represented in unorm8 or not.
>

I don't understand how it can be useful though, if I have an image
internally represented at -128..127, and I dump it as unorm 0.255 it
is going to actually me less useful I would guess as I'd try and
interpret it. Though I've no idea what negative color looks like, the
hooks are pretty easy to add in, but I'd like to add something to warn
if they ever get used.

Dave.