[Mesa-dev] [PATCH] st/mesa: fix default interpolation for colors. (v2)

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

Brian mentioned that mesa-demos/reflect was broken on softpipe,
by my previous commit. The problem was were blindly translating none
to perspective, when color/pntc at least need it linear.

v2: no regressions version.
use shademodel to pick what none means.

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 src/mesa/state_tracker/st_program.c |   19 ++++++++++++-------
 1 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/mesa/state_tracker/st_program.c b/src/mesa/state_tracker/st_program.c
index 146a9f3..1f6094e 100644
--- a/src/mesa/state_tracker/st_program.c
+++ b/src/mesa/state_tracker/st_program.c
@@ -436,10 +436,14 @@ st_get_vp_variant(struct st_context *st,
 
 
 static unsigned
-st_translate_interp(enum glsl_interp_qualifier glsl_qual)
+st_translate_interp(enum glsl_interp_qualifier glsl_qual, bool is_color, GLenum shade_model)
 {
    switch (glsl_qual) {
    case INTERP_QUALIFIER_NONE:
+      if (is_color)
+         if (shade_model == GL_FLAT)
+            return TGSI_INTERPOLATE_LINEAR;
+      return TGSI_INTERPOLATE_PERSPECTIVE;
    case INTERP_QUALIFIER_SMOOTH:
       return TGSI_INTERPOLATE_PERSPECTIVE;
    case INTERP_QUALIFIER_FLAT:
@@ -542,12 +546,14 @@ st_translate_fragment_program(struct st_context *st,
             case FRAG_ATTRIB_COL0:
                input_semantic_name[slot] = TGSI_SEMANTIC_COLOR;
                input_semantic_index[slot] = 0;
-               interpMode[slot] = st_translate_interp(stfp->Base.InterpQualifier[attr]);
+               interpMode[slot] = st_translate_interp(stfp->Base.InterpQualifier[attr],
+                                                      TRUE, st->ctx->Light.ShadeModel);
                break;
             case FRAG_ATTRIB_COL1:
                input_semantic_name[slot] = TGSI_SEMANTIC_COLOR;
                input_semantic_index[slot] = 1;
-               interpMode[slot] = st_translate_interp(stfp->Base.InterpQualifier[attr]);
+               interpMode[slot] = st_translate_interp(stfp->Base.InterpQualifier[attr],
+                                                      TRUE, st->ctx->Light.ShadeModel);
                break;
             case FRAG_ATTRIB_FOGC:
                input_semantic_name[slot] = TGSI_SEMANTIC_FOG;
@@ -601,10 +607,9 @@ st_translate_fragment_program(struct st_context *st,
                assert(attr >= FRAG_ATTRIB_TEX0);
                input_semantic_index[slot] = (attr - FRAG_ATTRIB_TEX0);
                input_semantic_name[slot] = TGSI_SEMANTIC_GENERIC;
-               if (attr == FRAG_ATTRIB_PNTC)
-                  interpMode[slot] = TGSI_INTERPOLATE_LINEAR;
-               else
-                  interpMode[slot] = st_translate_interp(stfp->Base.InterpQualifier[attr]);
+               interpMode[slot] = st_translate_interp(stfp->Base.InterpQualifier[attr],
+                                                      (attr == FRAG_ATTRIB_PNTC),
+                                                      st->ctx->Light.ShadeModel);
                break;
             }
          }
-- 
1.7.7.4