[Mesa-dev] [PATCH] r600g: implement fast color clears on evergreen+

[Marek Olšák]

On Tue, Jun 11, 2013 at 4:52 PM, Grigori Goronzy <greg at chown.ath.cx> wrote:
> On 11.06.2013 02:41, Marek Olšák wrote:
>>> +
>>> +               /* cannot pack color, needs support in u_format */
>>> +               if (desc->pack_rgba_float == NULL) {
>>> +                       return false;
>>> +               }
>>
>> Hi Grirogi,
>>
>> Is this for disallowing integer textures? You probably wanted to use
>> util_format_is_pure_integer, which is more clear. pack_rgba_float
>> should be non-NULL for every non-integer format.
>>
>
> Yes, that seems to be a better solution.
>
>
>> Anyway, it should be possible to support integer textures too, though
>> util_pack_color might need some improvements. If you are convinced
>> integer textures are not important, it's alright with me.
>>
>
> I'm not convinced that integer textures are not important, but they are not
> commonly used, as far as I can see. After all, MSAA seems to be broken with
> many integer formats (e.g. in the ext_framebuffer_multisample-formats piglit
> test), but nobody cared so far. :)

I do care, but the downsampling (color resolve) of 32-bits-per-channel
integer formats isn't supported by the hardware, so it would have to
be implemented in a fragment shader. Texturing works though, which is
more likely to be used with integer textures than the downsampling.

Marek