+/**
+ * Calculates the MRD for the depth format. MRD is used in depth bias
+ * for UNORM and unbound depth buffers. When the depth buffer is floating
+ * point, the depth bias calculation does not use the MRD. However, the
+ * default MRD will be 1.0 / ((1 << 24) - 1).
+ */
+double
+util_get_depth_format_mrd(enum pipe_format format)
+{
+ struct util_format_description *format_desc;
+ /*
+ * Depth buffer formats without a depth component OR scenarios
+ * without a bound depth buffer default to D24.
+ */
+ double mrd = 1.0 / ((1 << 24) - 1);
+ unsigned depth_channel;
+
+ format_desc = (struct util_format_description *)
+ util_format_description(format);
+
+ assert(format_desc);
+
+ /*
+ * Some depth formats do not store the depth component in the first
+ * channel, detect the format and adjust the depth channel. Get the
+ * swizzled depth component channel.
+ */
+ depth_channel = format_desc->swizzle[0];
+
+ if (format_desc->channel[depth_channel].type == UTIL_FORMAT_TYPE_UNSIGNED &&
+ format_desc->channel[depth_channel].normalized) {
+ int depth_bits;
+
+ depth_bits = format_desc->channel[depth_channel].size;
+ mrd = 1.0 / ((1ULL << depth_bits) - 1);
+ }
+
+ return mrd;
+}
+
+