st/mesa: handle SNORM formats in generic CopyPixels path

v2: check desc->is_mixed in util_format_is_snorm

1 files changed, 20 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_format.c b/src/gallium/auxiliary/util/u_format.c
index 9bdc2eabf11..686ca8a898e 100644
--- a/src/gallium/auxiliary/util/u_format.c
+++ b/src/gallium/auxiliary/util/u_format.c
@@ -131,6 +131,26 @@ util_format_is_pure_uint(enum pipe_format format)
    return (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED && desc->channel[i].pure_integer) ? TRUE : FALSE;
 }
 
+/**
+ * Returns true if all non-void channels are normalized signed.
+ */
+boolean
+util_format_is_snorm(enum pipe_format format)
+{
+   const struct util_format_description *desc = util_format_description(format);
+   int i;
+
+   if (desc->is_mixed)
+      return FALSE;
+
+   i = util_format_get_first_non_void_channel(format);
+   if (i == -1)
+      return FALSE;
+
+   return desc->channel[i].type == UTIL_FORMAT_TYPE_SIGNED &&
+          !desc->channel[i].pure_integer &&
+          desc->channel[i].normalized;
+}
 
 boolean
 util_format_is_luminance_alpha(enum pipe_format format)