From 37adbad3973e809845845a9f2fe73b847718da0a Mon Sep 17 00:00:00 2001
From: Jamie Reece Wilson <me@reece.sx>
Date: Sat, 18 Nov 2023 01:45:12 +0000
Subject: [PATCH] [*] IM NOT MAD. YOURE MAD (b88c61c1 cont)

---
 Source/RNG/AuRandomDevice.cpp | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/Source/RNG/AuRandomDevice.cpp b/Source/RNG/AuRandomDevice.cpp
index 64ecfa33..53ec4909 100644
--- a/Source/RNG/AuRandomDevice.cpp
+++ b/Source/RNG/AuRandomDevice.cpp
@@ -72,6 +72,13 @@ namespace Aurora::RNG
         return ret;
     }
 
+    static AuUInt64 RngConvertBounds(AuUInt32 i)
+    {
+        AuUInt8 ret;
+        AuBitScanReverse(ret, i);
+        return 1ull << (ret + 1);
+    }
+
     void     RandomDevice::NextString(char *pString, AuUInt32 uLength, ERngStringCharacters type)
     {
         static AuPair<const char *, int> rngSequence[static_cast<int>(ERngStringCharacters::eEnumCount)] =
@@ -81,7 +88,7 @@ namespace Aurora::RNG
             {"ABCDEFGHIJKLMNOPQRSTUVWXYZ", 26},
             {"1234567890", 10},
             {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890", 62},
-            {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890=-+!!$%^*.[];:", 76}
+            {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890=-+!$%^*.[];:", 75}
         };
 
         if (!pString)
@@ -102,7 +109,14 @@ namespace Aurora::RNG
 
         for (auto i = 0u; i < uLength; i++)
         {
-            pString[i] = pair.first[reinterpret_cast<const AuUInt8 *>(pString)[i] % static_cast<int>(pair.second)];
+            auto uUpperBound = RngConvertBounds(pair.second);
+            AuUInt8 uNext {};
+            auto uWord = reinterpret_cast<const AuUInt8 *>(pString)[i];
+            while ((uNext = (uWord & (uUpperBound - 1))) >= pair.second)
+            {
+                uWord = AuFnv1a32Runtime(&uWord, sizeof(uWord));
+            }
+            pString[i] = pair.first[uNext];
         }
     }
 
@@ -170,11 +184,11 @@ namespace Aurora::RNG
     #else
         auto uRange = uMax - uMin;
         auto uMassiveWord = NextU32();
-        auto uUpperBound = AuPageRoundUp<AuUInt32>(uRange, 2);
+        auto uUpperBound = RngConvertBounds(uRange + 1);
         AuUInt32 uNext {};
         while ((uNext = (uMassiveWord & (uUpperBound - 1))) > uRange)
         {
-            uMassiveWord = NextU32();
+            uMassiveWord = AuFnv1a32Runtime(&uMassiveWord, sizeof(uMassiveWord));
         }
         return uMin + uNext;
     #endif
@@ -188,11 +202,11 @@ namespace Aurora::RNG
     #else
         auto uRange = uMax - uMin;
         auto uMassiveWord = NextU32();
-        auto uUpperBound = AuPageRoundUp<AuUInt32>(uRange, 2);
+        auto uUpperBound = RngConvertBounds(uRange + 1);
         AuUInt32 uNext {};
         while ((uNext = (uMassiveWord & (uUpperBound - 1))) > uRange)
         {
-            uMassiveWord = NextU32();
+            uMassiveWord = AuFnv1a32Runtime(&uMassiveWord, sizeof(uMassiveWord));
         }
         return uMin + uNext;
     #endif
@@ -209,11 +223,11 @@ namespace Aurora::RNG
         return NextU32() % uCount;
     #else
         auto uMassiveWord = NextU32();
-        auto uUpperBound = AuPageRoundUp<AuUInt32>(uCount, 2);
+        auto uUpperBound = RngConvertBounds(uCount);
         AuUInt32 uNext {};
         while ((uNext = (uMassiveWord & (uUpperBound - 1))) >= uCount)
         {
-            uMassiveWord = NextU32();
+            uMassiveWord = AuFnv1a32Runtime(&uMassiveWord, sizeof(uMassiveWord));
         }
         return uNext;
     #endif