[Mesa-dev] [PATCH v2 4/5] gallium: Make a helper for doing Z32_FLOAT_S8X24_UINT mappings.

[Rob Clark]

On Thu, Nov 30, 2017 at 9:53 AM, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
> On 28.11.2017 15:01, Rob Clark wrote:
>>
>> On Tue, Nov 21, 2017 at 4:13 PM, Eric Anholt <eric at anholt.net> wrote:
>>>
>>> v2: Remove the callback, leave avoiding the recursion up to the caller
>>>      (probably by rewriting the vtbl either in pctx or u_resource_vtbl)
>>
>>
>> hmm, that is still a bit ugly..  and looking at the equiv thing that
>> Ilia implemented in freedreno, I think there is also so special
>> handling needed for ->transfer_flush_region()..
>>
>> If you don't want to add it in u_resource/_vtbl (and I agree, a per
>> rsc vtbl is kinda unneeded), maybe we could introduce in a similar
>> way, u_transfer_vtbl/u_transfer_resource/u_transfer, ie.
>>
>>    struct u_transfer_resource {
>>       struct pipe_resource b;
>>       struct pipe_resource *stencil; /* holds separate stencil buffer
>> for z32x24s8 */
>>    }
>>
>>    struct u_transfer {
>>       struct pipe_transfer b;
>>       void *staging;
>>    }
>>
>>    struct u_transfer_vtbl {
>>       struct pipe_resource (*resource_create)(...);
>>       void (*resource_destroy)(...);
>>       void *(*transfer_map)(...);
>>       void (*transfer_flush_region)(...);
>>       void (*transfer_unmap)(...);
>>       bool lower_z32s8;
>>       bool lower_rgtc;
>>    }
>
>
> I think this makes sense.
>
> Keep in mind that u_threaded_context also has a threaded_transfer wrapper of
> pipe_transfer. It doesn't really do anything for textures, but it might be
> useful to stay compatible. It's unlikely that radeonsi will start using
> these helpers, but other drivers may want to use Gallium threading.
>

fwiw, looking at u_threaded_context is somewhere on my TODO list..  I
did already send a u_transfer_helper patch, without considering
u_threaded_context.  I guess I'll figure out the threaded_transfer bit
when I get time to threadify freedreno.

btw, I thought radeonsi was one of the drivers that had to deal w/
separate s8/z32, so I would have thought this could be useful to you
too?  Although maybe not worth changing what already works.

BR,
-R