glsl: Distinguish between no interpolation qualifier and 'smooth'

Previously, we treated the 'smooth' qualifier as equivalent to no
qualifier at all.  However, this is incorrect for the built-in color
variables (gl_FrontColor, gl_BackColor, gl_FrontSecondaryColor, and
gl_BackSecondaryColor).  For those variables, if there is no qualifier
at all, interpolation should be flat if the shade model is GL_FLAT,
and smooth if the shade model is GL_SMOOTH.

To make this possible, I added a new value to the
glsl_interp_qualifier enum, INTERP_QUALIFIER_NONE.

Reviewed-by: Kenneth Graunke <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index d090d311da8..fa6206e5eb0 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -1965,8 +1965,10 @@ apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual,
       var->interpolation = INTERP_QUALIFIER_FLAT;
    else if (qual->flags.q.noperspective)
       var->interpolation = INTERP_QUALIFIER_NOPERSPECTIVE;
-   else
+   else if (qual->flags.q.smooth)
       var->interpolation = INTERP_QUALIFIER_SMOOTH;
+   else
+      var->interpolation = INTERP_QUALIFIER_NONE;
 
    var->pixel_center_integer = qual->flags.q.pixel_center_integer;
    var->origin_upper_left = qual->flags.q.origin_upper_left;