From 1ff63f3479389f977156048ba436a5e8f0990a0d Mon Sep 17 00:00:00 2001
From: Reece <me@reece.sx>
Date: Tue, 13 Jul 2021 13:09:10 +0100
Subject: [PATCH] [+] Added stub for fast rng [*] Fixed RNG strings may contain
 a null byte [+] Added RngByte, RngArray, RngBoolean

---
 Include/Aurora/RNG/RNG.hpp | 57 ++++++++++++++++++++++++++++++++------
 Source/RNG/RNG.cpp         |  6 ++++
 2 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/Include/Aurora/RNG/RNG.hpp b/Include/Aurora/RNG/RNG.hpp
index fff1ea31..9f10f4a1 100644
--- a/Include/Aurora/RNG/RNG.hpp
+++ b/Include/Aurora/RNG/RNG.hpp
@@ -10,17 +10,32 @@
 namespace Aurora::RNG
 {
     AUKN_SYM void ReadSecureRNG(void *in, AuUInt length);
-
-    template<typename T, int N>
+    AUKN_SYM void ReadFastRNG(void *in, AuUInt length);
+    
+    template<bool fast = true, typename T, int N>
     void Read(T(&array)[N])
     {
-        ReadSecureRNG(array, N * sizeof(T));
+        if constexpr (fast)
+        {
+            ReadFastRNG(array, N * sizeof(T));
+        }
+        else
+        {
+            ReadSecureRNG(array, N * sizeof(T));
+        }
     }
 
-    template<typename T>
+    template<bool fast = true, typename T>
     void Read(T *array, AuUInt length)
     {
-        ReadSecureRNG(array, length * sizeof(T));
+        if constexpr (fast)
+        {
+            ReadFastRNG(array, length * sizeof(T));
+        }
+        else
+        {
+            ReadSecureRNG(array, length * sizeof(T));
+        }
     }
 
     enum class RngStringCharacters
@@ -28,12 +43,12 @@ namespace Aurora::RNG
         eAlphaCharacters,
         eAlphaNumericCharacters,
         eExtendedEntropy,
-        MAX
+        eCount
     };
 
     static void RngString(char *string, AuUInt length, RngStringCharacters type = RngStringCharacters::eAlphaCharacters)
     {
-        static std::pair<const char *, int> rngSequence[static_cast<int>(RngStringCharacters::MAX)] =
+        static std::pair<const char *, int> rngSequence[static_cast<int>(RngStringCharacters::eCount)] =
         {
             {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ", 52},
             {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890", 62},
@@ -46,8 +61,34 @@ namespace Aurora::RNG
 
         for (auto i = 0; i < length; i++)
         {
-            auto idx = static_cast<float>(reinterpret_cast<AuUInt8 *>(string)[i]) / 255.f * static_cast<float>(pair.second);
+            auto idx = std::floor(static_cast<float>(reinterpret_cast<AuUInt8 *>(string)[i]) / 255.f * static_cast<float>(pair.second - 1));
             string[i] = pair.first[static_cast<int>(idx)];
         }
     }
+    
+    static bool RngBoolean()
+    {
+        AuUInt8 x[1];
+        Read<true>(x);
+        return x[0] > 127;
+    }
+
+    static AuUInt8 RngByte()
+    {
+        AuUInt8 x[1];
+        Read<true>(x);
+        return x[0];
+    }
+
+    template<typename T>
+    static T &RngArray(T *items, AuUInt count)
+    {
+        return items[static_cast<int>(std::floor(static_cast<float>(RngByte()) / 255.f * static_cast<float>(count - 1))];
+    }
+
+    template<typename T>
+    static T &RngVector(const AuList<T> &items)
+    {
+        return RngArray(items.data(), items.size());
+    }
 }
\ No newline at end of file
diff --git a/Source/RNG/RNG.cpp b/Source/RNG/RNG.cpp
index d6b91669..f0e39d20 100644
--- a/Source/RNG/RNG.cpp
+++ b/Source/RNG/RNG.cpp
@@ -173,6 +173,12 @@ namespace Aurora::RNG
         SysAssertExp(bytes == length, "Couldn't consume {} RNG bytes", length);
     }
 
+    AUKN_SYM void ReadFastRNG(void *in, AuUInt length)
+    {
+        // TODO: implement me
+        return ReadSecureRNG(in, length);
+    }
+
     void Init()
     {
         InitRandPlatform();