[Mesa-dev] GLSL linker issue when counting varying vars

[Ian Romanick]

On 06/22/2012 03:39 PM, Brian Paul wrote:
> The GLSL linker code in assign_varying_locations() counts up the number
> of varying variables and checks the count against the
> ctx->Const.MaxVarying limit.
>
> I know we've had problems with this in the past but I think there's
> another issue.
>
> In the case of fragment shaders we're also counting variables like
> gl_FrontFacing and gl_FragCoord against the limit. IMO, we shouldn't
> count those vars there since they're not really interpolated values like
> colors or texcoords or generic varyings.

Sadly, they are on some hardware.  This is one of the cases where we had 
talked about either having some flags to control which things the linker 
counts or giving the driver the ability to over-ride the count generated 
by the linker.

> Comments?
>
> -Brian