i965/fs: use determine_interpolation_mode().

This patch changes how fs_visitor::emit_general_interpolation()
decides what kind of interpolation to do.  Previously, it used the
shade model to determine how to interpolate colors, and used smooth
interpolation on everything else.  Now it uses
ir_variable::determine_interpolation_mode(), so that it respects GLSL
1.30 interpolation qualifiers.

Fixes piglit tests interpolation-flat-*-smooth-{distance,fixed,vertex}
and interpolation-flat-other-flat-{distance,fixed,vertex}.

Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index b3ad505b71e66954927e546c33ffee248e6613d2..185e00d5a28f65dc3d0bf34f2406451778b41d0f 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -442,6 +442,9 @@ fs_visitor::emit_general_interpolation(ir_variable *ir)
       type = ir->type;
    }
 
+   glsl_interp_qualifier interpolation_mode =
+      ir->determine_interpolation_mode(c->key.flat_shade);
+
    int location = ir->location;
    for (unsigned int i = 0; i < array_elements; i++) {
       for (unsigned int j = 0; j < type->matrix_columns; j++) {
@@ -454,10 +457,7 @@ fs_visitor::emit_general_interpolation(ir_variable *ir)
            continue;
         }
 
-        bool is_gl_Color =
-           location == FRAG_ATTRIB_COL0 || location == FRAG_ATTRIB_COL1;
-
-        if (c->key.flat_shade && is_gl_Color) {
+        if (interpolation_mode == INTERP_QUALIFIER_FLAT) {
            /* Constant interpolation (flat shading) case. The SF has
             * handed us defined values in only the constant offset
             * field of the setup reg.