Create our own Random class using the xoshiro256 algorithm

- This algorithm is typically used by .NET internally (and is Public Domain),
  but there is no guarantee that this is the case. By having a specific
  implementation, we should be able to guarantee deterministic output.
- Give access to the state of the Random object at any point via
  GetState and SetState methods that use Base64 strings. This should allow
  us to capture the RNG state if an error occurs and reproduce it regardless
  of if circumstances change.

Author: initsu

CommandLine/Program.cs

@@ -67,7 +67,7 @@ public int OnExecute()
 
         if (!Seed.HasValue) 
         {
-            var r = new Random();
+            var r = new System.Random();
             Seed = r.Next(1000000000);
         } 
         configuration!.Seed = Seed.Value.ToString();

CrossPlatformUI/ViewModels/RandomizerViewModel.cs

@@ -97,7 +97,7 @@ public RandomizerViewModel(MainViewModel main)
 
         RerollSeed = ReactiveCommand.Create(() =>
         {
-            Main.Config.Seed = new Random().Next(0, 999999999).ToString();
+            Main.Config.Seed = new System.Random().Next(0, 999999999).ToString();
         });
 
         LoadPreset = ReactiveCommand.Create<RandomizerConfiguration>(config =>

RandomizerCore/CharacterSprite.cs

@@ -56,7 +56,7 @@ public CharacterSprite(string displayName, byte[]? patch = null)
 
     public static CharacterSprite Random(CharacterSprite[] options)
     {
-        Random random = new Random();
+        System.Random random = new();
         return options[random.Next(options.Length - 1)];
     }
 };

RandomizerCore/Hyrule.cs

@@ -1,18 +1,16 @@
-using DynamicData;
-using FtRandoLib.Importer;
-using js65;
-using NLog;
-using System;
+using System;
 using System.Buffers;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
-using System.Reflection;
 using System.Text;
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
+using NLog;
+using js65;
+using FtRandoLib.Importer;
 using Z2Randomizer.RandomizerCore.Enemy;
 using Z2Randomizer.RandomizerCore.Overworld;
 using Z2Randomizer.RandomizerCore.Sidescroll;
@@ -174,7 +172,7 @@ public class Hyrule
     */
 
     public ROM ROMData { get; set; }
-    public Random r { get; set; }
+    public RandomizerCore.Random r { get; set; }
     public string Flags { get; private set; }
     public int SeedHash { get; private set; }
     public RandomizerProperties Props
@@ -459,7 +457,7 @@ public async Task<RandomizerResult> Randomize(byte[] vanillaRomData, RandomizerC
                     }
                 }
 
-                Random musicRng = new(SeedHash);
+                RandomizerCore.Random musicRng = new(SeedHash);
                 bool success = false;
                 int triesLeft = 8;
                 while (!success)
@@ -1273,7 +1271,7 @@ private async Task<bool> FillPalaceRooms(AsmModule sideviewModule)
         try
         {
             ROM testRom = new(ROMData);
-            Random testRng = new Random();
+            RandomizerCore.Random testRng = new(SeedHash);
             //This continues to get worse, the text is based on the palaces and asm patched, so it needs to
             //be tested here, but we don't actually know what they will be until later, for now i'm just
             //testing with the vanilla text, but this could be an issue down the line.
@@ -2262,7 +2260,7 @@ private void SwapUpAndDownstab()
     }
 
     //Updated to use fisher-yates. Eventually i'll catch all of these. N is small enough here it REALLY makes a difference
-    private static void ShuffleEncounters(ROM rom, Random r, List<int> addr)
+    private static void ShuffleEncounters(ROM rom, RandomizerCore.Random r, List<int> addr)
     {
         for (int i = addr.Count - 1; i > 0; --i)
         {
@@ -2274,7 +2272,7 @@ private static void ShuffleEncounters(ROM rom, Random r, List<int> addr)
         }
     }
 
-    private void RandomizeStartingValues(RandomizerProperties props, Assembler a, Random r, ROM rom)
+    private void RandomizeStartingValues(RandomizerProperties props, Assembler a, RandomizerCore.Random r, ROM rom)
     {
 
         rom.Put(0x17AF3, (byte)props.StartAtk);
@@ -3591,7 +3589,7 @@ private void ChangeMapperToMMC5(Assembler asm, bool preventFlash, bool enableZ2F
         a.Code(Util.ReadResource("Z2Randomizer.RandomizerCore.Asm.MMC5.s"), "mmc5_conversion.s");
     }
 
-    private void ApplyAsmPatches(RandomizerProperties props, Assembler engine, Random r, List<Text> texts, ROM rom, StatRandomizer randomizedStats)
+    private void ApplyAsmPatches(RandomizerProperties props, Assembler engine, RandomizerCore.Random r, List<Text> texts, ROM rom, StatRandomizer randomizedStats)
     {
         bool randomizeMusic = !props.DisableMusic && props.RandomizeMusic;
 

RandomizerCore/Music.cs

@@ -158,7 +158,7 @@ public MusicRandomizer(
         bool safeOnly)
     {
         _hyrule = hyrule;
-        _shuffler = new RandomShuffler(new Random(seed));
+        _shuffler = new RandomShuffler(new System.Random(seed));
         _rom = _hyrule.ROMData.GetBytes(0, ROM.RomSize);
         _romAccess = new(_rom);
         _jsonLibPaths = new(jsonLibPaths);

RandomizerCore/ROM.cs

@@ -616,7 +616,7 @@ public void UpdateSpritePalette(NesColor tunicColor, NesColor skinTone, NesColor
 
         static int RandomUniqueColor(params int?[] forbiddenColors)
         {
-            Random random = new Random();
+            System.Random random = new();
             int color;
             do
             {
@@ -678,7 +678,7 @@ public void UpdateProjectileSprite(BeamSprites beamSprite)
     {
         if (beamSprite == BeamSprites.RANDOM)
         {
-            Random r2 = new();
+            System.Random r2 = new();
             beamSprite = (BeamSprites)r2.Next(Enum.GetValues(typeof(BeamSprites)).Length - 1);
         }