2 files changed, 46 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_format.c b/src/gallium/auxiliary/util/u_format.c
index 18456371c0a..9bdc2eabf11 100644
--- a/src/gallium/auxiliary/util/u_format.c
+++ b/src/gallium/auxiliary/util/u_format.c
@@ -632,6 +632,40 @@ void util_format_compose_swizzles(const unsigned char swz1[4],
    }
 }
 
+void util_format_apply_color_swizzle(union pipe_color_union *dst,
+                                     const union pipe_color_union *src,
+                                     const unsigned char swz[4],
+                                     const boolean is_integer)
+{
+   unsigned c;
+
+   if (is_integer) {
+      for (c = 0; c < 4; ++c) {
+         switch (swz[c]) {
+         case PIPE_SWIZZLE_RED:   dst->ui[c] = src->ui[0]; break;
+         case PIPE_SWIZZLE_GREEN: dst->ui[c] = src->ui[1]; break;
+         case PIPE_SWIZZLE_BLUE:  dst->ui[c] = src->ui[2]; break;
+         case PIPE_SWIZZLE_ALPHA: dst->ui[c] = src->ui[3]; break;
+         default:
+            dst->ui[c] = (swz[c] == PIPE_SWIZZLE_ONE) ? 1 : 0;
+            break;
+         }
+      }
+   } else {
+      for (c = 0; c < 4; ++c) {
+         switch (swz[c]) {
+         case PIPE_SWIZZLE_RED:   dst->f[c] = src->f[0]; break;
+         case PIPE_SWIZZLE_GREEN: dst->f[c] = src->f[1]; break;
+         case PIPE_SWIZZLE_BLUE:  dst->f[c] = src->f[2]; break;
+         case PIPE_SWIZZLE_ALPHA: dst->f[c] = src->f[3]; break;
+         default:
+            dst->f[c] = (swz[c] == PIPE_SWIZZLE_ONE) ? 1.0f : 0.0f;
+            break;
+         }
+      }
+   }
+}
+
 void util_format_swizzle_4f(float *dst, const float *src,
                             const unsigned char swz[4])
 {
diff --git a/src/gallium/auxiliary/util/u_format.h b/src/gallium/auxiliary/util/u_format.h
index ed942fb1658..e4b9c365c97 100644
--- a/src/gallium/auxiliary/util/u_format.h
+++ b/src/gallium/auxiliary/util/u_format.h
@@ -33,6 +33,9 @@
 #include "pipe/p_format.h"
 #include "util/u_debug.h"
 
+union pipe_color_union;
+
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -1117,6 +1120,15 @@ void util_format_compose_swizzles(const unsigned char swz1[4],
                                   const unsigned char swz2[4],
                                   unsigned char dst[4]);
 
+/* Apply the swizzle provided in \param swz (which is one of PIPE_SWIZZLE_x)
+ * to \param src and store the result in \param dst.
+ * \param is_integer determines the value written for PIPE_SWIZZLE_ONE.
+ */
+void util_format_apply_color_swizzle(union pipe_color_union *dst,
+                                     const union pipe_color_union *src,
+                                     const unsigned char swz[4],
+                                     const boolean is_integer);
+
 void util_format_swizzle_4f(float *dst, const float *src,
                             const unsigned char swz[4]);