[Mesa-dev] ARB_framebuffer_no_attachments for llvm and soft pipes

[Dave Airlie]

On 14 April 2016 at 01:37, Roland Scheidegger <sroland at vmware.com> wrote:
> Am 13.04.2016 um 03:35 schrieb eocallaghan at alterapraxis.com:
>> On 2016-04-11 22:27, Roland Scheidegger wrote:
>>> Am 10.04.2016 um 09:41 schrieb Edward O'Callaghan:
>>>> All the piglits pass for these two as-is. However, some of the piglits
>>>> require SSBO support to run, although I can't see why anything would
>>>> actually fail but I thought I would make note of it just in case someone
>>>> felt this patch should be held back till SSBO support is in both pipe
>>>> drivers? If not, we should be golden to flick these on too.
>>>>
>>>> Edward O'Callaghan (1):
>>>>   llvmpipe,softpipe: Enable ARB_framebuffer_no_attachments
>>>
>>>
>>> I'm not sure this is really a good idea (at least for llvmpipe). At
>>> least the number of layers used internally is wrong (fb_max_layer is
>>> going to be ~0 as it is always derived from the attached buffrs). I
>>> suppose though it might not actually matter. But I'm not sure if there's
>>> really any point in this extension without images - while I initially
>>> thought it wouldn't be able to do anything this isn't quite true as
>>> there is indeed one side effect of fs possible even without images,
>>> which is query results (such as occlusion queries, which is what piglit
>>> uses).
>>> I think though just about all practical use cases really would require
>>> image support, so I'm not convinced exposing this just because we can is
>>> worth it. But OTOH why not...
>>
>> That was essentially how I rationalized it also.
>>
>>>
>>> Reviewed-by: Roland Scheidegger <sroland at vmware.com>
>>
>> I never applied for commit bit yet so if you still want it your have to
>> merge.
>>
>> Kind Regards,
>> Edward.
>
> Softpipe actually does support ssbo now, so it should be enabled there -
> if it actually passes the tests now with this enabled.

I got some time yesterday and tested/pushed the softpipe part of this.

I think we should hold off on llvmpipe until it has images/ssbos.

Dave.