[Mesa-dev] [PATCH 2/2] glsl: set user defined varyings to smooth by default

[Iago Toral]

On Mon, 2016-02-15 at 18:38 +1100, Timothy Arceri wrote:
> This is usually handled by the backends in order to handle the
> various interactions with the gl_*Color built-ins.
> 
> The problem is this means linking will fail if one side on the
> interface adds the smooth qualifier to the varying and the other
> side just uses the default even though they match.
> 
> This fixes various deqp tests and should have no impact on
> built-ins as they generate GLSL IR directly.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92743
> ---
>  src/compiler/glsl/ast_to_hir.cpp | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
> index b639378..47d52ee 100644
> --- a/src/compiler/glsl/ast_to_hir.cpp
> +++ b/src/compiler/glsl/ast_to_hir.cpp
> @@ -2750,6 +2750,11 @@ interpret_interpolation_qualifier(const struct ast_type_qualifier *qual,
>                            "vertex shader inputs or fragment shader outputs",
>                            interpolation_string(interpolation));
>        }
> +   } else if ((mode == ir_var_shader_in &&
> +               state->stage != MESA_SHADER_VERTEX) ||
> +              (mode == ir_var_shader_out &&
> +               state->stage != MESA_SHADER_FRAGMENT)) {
> +      interpolation = INTERP_QUALIFIER_SMOOTH;
>     }

The GLES spec explicitly says that in the absence of an interp qualifier
smooth is used, but I can't find the same statement in the desktop GLSL
spec. Should we make this ES specific?

Iago