[Mesa-dev] [PATCH v2 05/11] i965: Add and use a getter for the clear color

[Nanley Chery]

Use a getter which allows CNL to sample from sRGB textures correctly.

Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>
---
 src/mesa/drivers/dri/i965/brw_blorp.c            |  4 +++-
 src/mesa/drivers/dri/i965/brw_wm_surface_state.c |  4 +++-
 src/mesa/drivers/dri/i965/intel_mipmap_tree.c    | 25 ++++++++++++++++++++++++
 src/mesa/drivers/dri/i965/intel_mipmap_tree.h    |  7 +++++++
 4 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_blorp.c b/src/mesa/drivers/dri/i965/brw_blorp.c
index 6ab5267ddea..c6fa5195ee3 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp.c
+++ b/src/mesa/drivers/dri/i965/brw_blorp.c
@@ -172,7 +172,9 @@ blorp_surf_for_miptree(struct brw_context *brw,
       /* We only really need a clear color if we also have an auxiliary
        * surface.  Without one, it does nothing.
        */
-      surf->clear_color = mt->fast_clear_color;
+      surf->clear_color =
+         intel_miptree_get_clear_color(devinfo, mt, mt->surf.format,
+                                       !is_render_target);
 
       surf->aux_surf = aux_surf;
       surf->aux_addr = (struct blorp_address) {
diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
index caa92d7d878..2c9e986b184 100644
--- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
@@ -178,7 +178,9 @@ brw_emit_surface_state(struct brw_context *brw,
       /* We only really need a clear color if we also have an auxiliary
        * surface.  Without one, it does nothing.
        */
-      clear_color = mt->fast_clear_color;
+      clear_color =
+         intel_miptree_get_clear_color(devinfo, mt, view.format,
+                                       view.usage & ISL_SURF_USAGE_TEXTURE_BIT);
    }
 
    void *state = brw_state_batch(brw,
diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
index 7aa0e7920d3..c21c4d8bae1 100644
--- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
@@ -46,6 +46,9 @@
 #include "main/texcompress_etc.h"
 #include "main/teximage.h"
 #include "main/streaming-load-memcpy.h"
+
+#include "util/format_srgb.h"
+
 #include "x86/common_x86_asm.h"
 
 #define FILE_DEBUG_FLAG DEBUG_MIPTREE
@@ -3800,3 +3803,25 @@ intel_miptree_set_depth_clear_value(struct brw_context *brw,
    }
    return false;
 }
+
+union isl_color_value
+intel_miptree_get_clear_color(const struct gen_device_info *devinfo,
+                              const struct intel_mipmap_tree *mt,
+                              enum isl_format view_format,
+                              bool sampling)
+{
+   /* Prior to gen10, the clear color can be used unchanged. From gen10
+    * onwards, HW no longer gamma-corrects the clear color for sampling
+    * operations.
+    */
+   if (devinfo->gen >= 10 && isl_format_is_srgb(view_format) && sampling) {
+      union isl_color_value linear_color = mt->fast_clear_color;
+      for (unsigned i = 0; i < 3; i++) {
+         linear_color.f32[i] =
+            util_format_srgb_to_linear_float(mt->fast_clear_color.f32[i]);
+      }
+      return linear_color;
+   } else {
+      return mt->fast_clear_color;
+   }
+}
diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.h b/src/mesa/drivers/dri/i965/intel_mipmap_tree.h
index 961f8fe812e..e66a2a8d384 100644
--- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.h
+++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.h
@@ -720,6 +720,13 @@ intel_miptree_set_clear_color(struct brw_context *brw,
                               struct intel_mipmap_tree *mt,
                               const union gl_color_union *color);
 
+/* Get a clear color suitable for filling out an ISL surface state. */
+union isl_color_value
+intel_miptree_get_clear_color(const struct gen_device_info *devinfo,
+                              const struct intel_mipmap_tree *mt,
+                              enum isl_format view_format,
+                              bool sampling);
+
 bool
 intel_miptree_set_depth_clear_value(struct brw_context *brw,
                                     struct intel_mipmap_tree *mt,
-- 
2.16.2