1 files changed, 17 insertions, 0 deletions
diff --git a/mesalib/src/gallium/auxiliary/util/u_format.c b/mesalib/src/gallium/auxiliary/util/u_format.c
index d53dd7884..c1ce40811 100644
--- a/mesalib/src/gallium/auxiliary/util/u_format.c
+++ b/mesalib/src/gallium/auxiliary/util/u_format.c
@@ -92,6 +92,23 @@ util_format_is_luminance(enum pipe_format format)
 }
 
 boolean
+util_format_is_alpha(enum pipe_format format)
+{
+   const struct util_format_description *desc =
+      util_format_description(format);
+
+   if ((desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
+        desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
+       desc->swizzle[0] == UTIL_FORMAT_SWIZZLE_0 &&
+       desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_0 &&
+       desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_0 &&
+       desc->swizzle[3] == UTIL_FORMAT_SWIZZLE_X) {
+      return TRUE;
+   }
+   return FALSE;
+}
+
+boolean
 util_format_is_pure_integer(enum pipe_format format)
 {
    const struct util_format_description *desc = util_format_description(format);