From 6d7d14a3e29418b8bb25ce8f1bd7a28b0c88d896 Mon Sep 17 00:00:00 2001
From: Jamie Reece Wilson <me@reece.sx>
Date: Sun, 7 Jan 2024 03:40:04 +0000
Subject: [PATCH] [*] Fixup AuRoundUpPow2 to not round up when the value is
 already a pow of 2 [+] AuIsPow2 [+] AuNextPow2

---
 Include/auROXTL/auNumberUtils.hpp | 32 +++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/Include/auROXTL/auNumberUtils.hpp b/Include/auROXTL/auNumberUtils.hpp
index 48cf90d..3d07a2b 100644
--- a/Include/auROXTL/auNumberUtils.hpp
+++ b/Include/auROXTL/auNumberUtils.hpp
@@ -42,10 +42,33 @@ constexpr const T AuPageRound(const T value, const T pageSize)
 // TODO: out of order
 #include "auBitsUtils.hpp"
 
+template <class T>
+const bool AuIsPow2(const T value)
+{
+    return (value) && (value & (value - 1) == 0);
+}
+
+template <class T>
+const T AuNextPow2(const T value)
+{
+    if constexpr (AuIsSame_v<T, AuUInt16> ||
+                  AuIsSame_v<T, AuUInt8>)
+    {
+        return AuNextPow2<AuUInt32>(value);
+    }
+    else
+    {
+        AuUInt8 ret;
+        AuBitScanReverse(ret, value);
+        return T(1) << (T(ret) + T(1));
+    }
+}
+
 template <class T>
 const T AuRoundUpPow2(const T value)
 {
-    if constexpr (AuIsSame_v<T, AuUInt16>)
+    if constexpr (AuIsSame_v<T, AuUInt16> ||
+                  AuIsSame_v<T, AuUInt8>)
     {
         return AuRoundUpPow2<AuUInt32>(value);
     }
@@ -53,14 +76,15 @@ const T AuRoundUpPow2(const T value)
     {
         AuUInt8 ret;
         AuBitScanReverse(ret, value);
-        return T(1) << (ret + T(1));
+        return T(1) << (T(ret) + T(T(1) << T(ret) == value ? 0 : 1));
     }
 }
 
 template <class T>
 const T AuRoundDownPow2(const T value)
 {
-    if constexpr (AuIsSame_v<T, AuUInt16>)
+    if constexpr (AuIsSame_v<T, AuUInt16> ||
+                  AuIsSame_v<T, AuUInt8>)
     {
         return AuRoundDownPow2<AuUInt32>(value);
     }
@@ -68,6 +92,6 @@ const T AuRoundDownPow2(const T value)
     {
         AuUInt8 ret;
         AuBitScanReverse(ret, value);
-        return T(1) << ret;
+        return T(1) << T(ret);
     }
 }
\ No newline at end of file