[Mesa-dev] [PATCH 21/23] anv/formats: Set the swizzle to RGB1 when using an RGBA format to fake RGB

[Jason Ekstrand]

This way we get correct sampling from RGB formats that are faked as RGBA.
This should also cause it to disable rendering and blending on those
formats.  We should be able to render to them and, on Broadwell and above,
we can blend on them with work-arounds.  However, we'll add support for
that more properly later when it's deemed useful.  For now, disabling
rendering and blending should be safe.
---
 src/intel/vulkan/anv_formats.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/intel/vulkan/anv_formats.c b/src/intel/vulkan/anv_formats.c
index 228f467..233abc1 100644
--- a/src/intel/vulkan/anv_formats.c
+++ b/src/intel/vulkan/anv_formats.c
@@ -34,6 +34,7 @@
 
 #define RGBA ISL_SWIZZLE(RED, GREEN, BLUE, ALPHA)
 #define BGRA ISL_SWIZZLE(BLUE, GREEN, RED, ALPHA)
+#define RGB1 ISL_SWIZZLE(RED, GREEN, BLUE, ONE)
 
 #define swiz_fmt(__vk_fmt, __hw_fmt, __swizzle)     \
    [__vk_fmt] = { \
@@ -278,10 +279,12 @@ anv_get_format(VkFormat vk_format, VkImageAspectFlags aspect,
        * hood.
        */
       enum isl_format rgbx = isl_format_rgb_to_rgbx(format.isl_format);
-      if (rgbx != ISL_FORMAT_UNSUPPORTED)
+      if (rgbx != ISL_FORMAT_UNSUPPORTED) {
          format.isl_format = rgbx;
-      else
+      } else {
          format.isl_format = isl_format_rgb_to_rgba(format.isl_format);
+         format.swizzle = (struct anv_format_swizzle) RGB1;
+      }
    }
 
    return format;
-- 
2.5.0.400.gff86faf