From 866a29e1532bca11098f0f0f74cdd29a0418b151 Mon Sep 17 00:00:00 2001
From: Triang3l <triang3l@yandex.ru>
Date: Sat, 5 Jun 2021 15:04:06 +0300
Subject: [PATCH] [Base] saturate_signed NaN comment

---
 src/xenia/base/math.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/xenia/base/math.h b/src/xenia/base/math.h
index 291e23a27..ac3ef8056 100644
--- a/src/xenia/base/math.h
+++ b/src/xenia/base/math.h
@@ -64,6 +64,10 @@ template <typename T>
 constexpr T saturate_unsigned(T value) {
   return std::min(static_cast<T>(1.0f), std::max(static_cast<T>(0.0f), value));
 }
+
+// This diverges from the GPU NaN rules for signed normalized formats (NaN
+// should be converted to 0, not to -1), but this expectation is not needed most
+// of time, and cannot be met for free (unlike for 0...1 clamping).
 template <typename T>
 constexpr T saturate_signed(T value) {
   return std::min(static_cast<T>(1.0f), std::max(static_cast<T>(-1.0f), value));