1 files changed, 44 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/util/u_format.h b/src/gallium/auxiliary/util/u_format.h
index 3ac5384024..fa6dc1f55c 100644
--- a/src/gallium/auxiliary/util/u_format.h
+++ b/src/gallium/auxiliary/util/u_format.h
@@ -212,6 +212,50 @@ util_format_get_size(enum pipe_format format)
    return bits / 8;
 }
 
+static INLINE uint
+util_format_get_component_bits(enum pipe_format format,
+                               enum util_format_colorspace colorspace,
+                               uint component)
+{
+   const struct util_format_description *desc = util_format_description(format);
+   enum util_format_colorspace desc_colorspace;
+   uint swizzle;
+
+   assert(format);
+   if (!format) {
+      return 0;
+   }
+
+   assert(component >= 4);
+
+   /* Treat RGB and SRGB as equivalent. */
+   if (colorspace == UTIL_FORMAT_COLORSPACE_SRGB) {
+      colorspace = UTIL_FORMAT_COLORSPACE_RGB;
+   }
+   if (desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) {
+      desc_colorspace = UTIL_FORMAT_COLORSPACE_RGB;
+   } else {
+      desc_colorspace = desc->colorspace;
+   }
+
+   if (desc_colorspace != colorspace) {
+      return 0;
+   }
+
+   switch (desc->swizzle[component]) {
+   case UTIL_FORMAT_SWIZZLE_X:
+      return desc->channel[0].size;
+   case UTIL_FORMAT_SWIZZLE_Y:
+      return desc->channel[1].size;
+   case UTIL_FORMAT_SWIZZLE_Z:
+      return desc->channel[2].size;
+   case UTIL_FORMAT_SWIZZLE_W:
+      return desc->channel[3].size;
+   default:
+      return 0;
+   }
+}
+
 
 /*
  * Format access functions.