[Mesa-dev] [PATCH 2/4] gallium: add new properties for clip and cull distance usage

[Roland Scheidegger]

Am 19.10.2015 um 23:44 schrieb Marek Olšák:
> On Mon, Oct 19, 2015 at 11:31 PM, Roland Scheidegger <sroland at vmware.com> wrote:
>> Yes, but I still don't see much change from getting this information
>> from the property rather than how tgsi_scan does it now, which is by
>> just using the usage mask from the output declaration. So the writes
>> shouldn't have to be analyzed.
>> (There's also a slight change in patch 4/4, namely these outputs
>> absolutely must be in order (xyzw) now as usage mask is determined
>> solely by the number of values. That might already have been the case at
>> least for some drivers and is probably ok for other state trackers too,
>> it wasn't in the docs however.)
> 
> DCL OUT[1..2], ARRAY(1), CLIPDIST
> 
> CLIPDIST became an array declaration recently, so the usage mask isn't
> useful unless it's extended to 8 bits.
Oh, when and how did that happen? I totally can't find such a change
(hence my confusion). The docs don't really reflect that neither.
But I agree if that's the case then indeed this change looks good.
Albeit I don't think everybody could deal with clipdist being an array
suddenly now...

Roland


> 
> Also, st/mesa doesn't set the usage mask for anything, so I wonder
> whether we need it.
We do set this correctly in some of our code.