[Mesa-dev] [PATCH 08/18] radeonsi: get info about VS outputs from tgsi_shader_info

[Marek Olšák]

Our hw can only do 6 legacy clip planes without ClipVertex. We would
have to lower them to clip distances to be able to support 8, which is
something I'd rather not do. (there would be more shader work or more
shader variants)

Marek

On Tue, Dec 9, 2014 at 4:29 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Tue, Dec 9, 2014 at 10:22 AM, Marek Olšák <maraeo at gmail.com> wrote:
>> It looks like clip planes are deprecated, so you can only use them
>> with the compatibility profile.
>
> Right.
>
>>
>> Sure we could support 8 clip planes if ClipVertex is written, but:
>> - we can only support 6 clip planes if ClipVertex isn't written
>> - pipe_context::set_clip_state can set only 6 clip planes
>
> That seems like an oversight in your driver, no? I don't see anything
> in mesa/st that would prevent me from setting and enabling all 8 clip
> planes in a compat context. Anyways, I guess given that you only ever
> look at the first 6 clip planes in your set_clip_state logic, that six
> bits thing is internally consistent :) FWIW in nv50 (and fairly sure
> nvc0 as well) we support all 8 UCP's.
>
>   -ilia