[Mesa-dev] [PATCH 0/4] Removal of point size clamping in st/mesa

[Marek Olšák]

On Sat, Jan 28, 2012 at 2:37 AM, Roland Scheidegger <sroland at vmware.com> wrote:
> Am 28.01.2012 01:38, schrieb Marek Olšák:
>> Hi everyone,
>>
>> the subject says it all. This series fixes gl_PointSize with transform feedback. There is a new piglit test to verify that a driver does clamping properly during rasterization: vs-point_size-zero
>>
>> I haven't changed Draw, because softpipe and llvmpipe do the clamping internally somewhere. (I didn't take a look where they do it, but they pass the test, which can't be said about r600 with point size clamping disabled)
>>
>> The only drivers I am not sure about are i915 and nouveau.
>>
>> Please review.
>
> This looks generally ok to me. I'd like to see more comment for [4/4],
> e.g. why this is ok (something along the lines that drivers are expected
> to clamp against their advertized point size limits whatever they are
> and depending on point smooth etc.).

More comment where? In the commit message or in the code?

> For [1/4] I can't quite tell off-hand if the point size min rs applies
> everywhere only hope so...
> I believe the conditions in [1,2,3/4] should also take multisampling
> into account, since point rendering with multisampling also works
> differently (and will produce zero-sized points).
> Also maybe for the hw drivers there should be some comment why actually
> min size is 1.0, as this is merely a workaround for chips which can't
> follow legacy OGL's totally silly point rasterization rules (about as
> silly as smooth points...).

I updated the patches, they can be read here:
http://cgit.freedesktop.org/~mareko/mesa/log/?h=point-size-clamp

I added a helper function returning the expected minimum point size,
it also checks for multisample and gl_rasterization_rules:
http://cgit.freedesktop.org/~mareko/mesa/commit/?h=point-size-clamp&id=a57d828e924c3fbee1d4707c3cefe4a8b92deef6

Marek