[Mesa-dev] [PATCH 00/21] Gallium: making user vertex buffers optional and other goodness

[Marek Olšák]

On Thu, Apr 12, 2012 at 10:26 AM, Christian König
<deathsimple at vodafone.de> wrote:
>
> It looks like a step into the right direction to me, cause AFAIK we need

I thought so too, but if radeon drivers are the only users of this,
there's not much point in doing it in the state tracker. I'd like to
know about at least one non-radeon driver intending to use this
functionality for it to go in.

> something similar for radeonsi as well, but I think you should fix (3)
> before committing it.
>
> As a side note, I really wonder why r600g doesn't support scaled/norm
> integer formats with 32 bits per channel?
> Well the hardware fetcher doesn't support converting from 32 integers to
> floats, but you can always fetch them as integers and call INT_TO_FLT in the
> fetch shader manually. Not much of an optimization, but at least a quite low
> hanging fruit.

Nobody has implemented that so far. We could probably support any data
type if we add proper conversion code in the fetch shader. We also
lower the strides and offsets which are not aligned to 4, but that's
not always required. AFAIK only some radeons can't do it and my
Evergreen card seems not to have a problem with it.

Marek