[Mesa-dev] Properly exposing limits with gallium

[Marek Olšák]

On Thu, Jul 30, 2015 at 10:21 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> So I'm trying to get these things to line up, especially for nvc0.
>
> Here are the limits exposed by the blob drivers:
>
> http://people.freedesktop.org/~imirkin/glxinfo/glxinfo.html#v=Vendor
>
> and they reflect what the hardware is capable. More specifically, I need
>
> GL_MAX_VERTEX_OUTPUT_COMPONENTS = 128
> GL_MAX_VARYING_FLOATS_ARB = 124
> GL_MAX_FRAGMENT_INPUT_COMPONENTS = 128
> GL_MAX_GEOMETRY_INPUT_COMPONENTS = 128
> GL_MAX_GEOMETRY_OUTPUT_COMPONENTS = 128
>
> What would the proper way to expose this be? Should we always just say
> MAX_VARYING_FLOATS = MAX_VERTEX_OUTPUT_COMPONENTS - 4? Or a separate
> PIPE_SHADER_CAP for the maxvaryingfloats?

According to the spec, the former. It looks like all outputs are
counted against the limit, but one of them doesn't include
gl_Position.

Marek