[Mesa-dev] [PATCH] st/mesa: don't set vs.key.clamp_color if a shader doesn't write any colors

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

And update some comments.
---
 src/mesa/state_tracker/st_atom_shader.c    | 7 ++++++-
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 4 ++--
 src/mesa/state_tracker/st_mesa_to_tgsi.c   | 4 ++--
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/mesa/state_tracker/st_atom_shader.c b/src/mesa/state_tracker/st_atom_shader.c
index 6515a98..73768ed 100644
--- a/src/mesa/state_tracker/st_atom_shader.c
+++ b/src/mesa/state_tracker/st_atom_shader.c
@@ -149,7 +149,12 @@ update_vp( struct st_context *st )
    key.passthrough_edgeflags = st->vertdata_edgeflags;
 
    key.clamp_color = st->clamp_vert_color_in_shader &&
-                     st->ctx->Light._ClampVertexColor;
+                     st->ctx->Light._ClampVertexColor &&
+                     (stvp->Base.Base.OutputsWritten &
+                      (VARYING_SLOT_COL0 |
+                       VARYING_SLOT_COL1 |
+                       VARYING_SLOT_BFC0 |
+                       VARYING_SLOT_BFC1));
 
    st->vp_variant = st_get_vp_variant(st, stvp, &key);
 
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index c3d7793..98ab2c1 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -4412,8 +4412,8 @@ translate_dst(struct st_translate *t,
       /* Clamp colors for ARB_color_buffer_float. */
       switch (t->procType) {
       case TGSI_PROCESSOR_VERTEX:
-         /* XXX if the geometry shader is present, this must be done there
-          * instead of here. */
+         /* This can only occur with a compatibility profile, which doesn't
+          * support geometry shaders. */
          if (dst_reg->index == VARYING_SLOT_COL0 ||
              dst_reg->index == VARYING_SLOT_COL1 ||
              dst_reg->index == VARYING_SLOT_BFC0 ||
diff --git a/src/mesa/state_tracker/st_mesa_to_tgsi.c b/src/mesa/state_tracker/st_mesa_to_tgsi.c
index 2c9d9a5..3dd8a14 100644
--- a/src/mesa/state_tracker/st_mesa_to_tgsi.c
+++ b/src/mesa/state_tracker/st_mesa_to_tgsi.c
@@ -299,8 +299,8 @@ translate_dst( struct st_translate *t,
       /* Clamp colors for ARB_color_buffer_float. */
       switch (t->procType) {
       case TGSI_PROCESSOR_VERTEX:
-         /* XXX if the geometry shader is present, this must be done there
-          * instead of here. */
+         /* This can only occur with a compatibility profile, which doesn't
+          * support geometry shaders. */
          if (DstReg->Index == VARYING_SLOT_COL0 ||
              DstReg->Index == VARYING_SLOT_COL1 ||
              DstReg->Index == VARYING_SLOT_BFC0 ||
-- 
2.1.0