From d286beadd312c608bcfd6d10e59f039ef66b747e Mon Sep 17 00:00:00 2001
From: Olly <Olly.cain@outlook.com>
Date: Sat, 5 Aug 2023 21:14:33 +0100
Subject: [PATCH] Better Randomize

---
 .../imports/simba/simba.import_random.pas     | 16 ++++++++-
 Source/simba.init.pas                         |  7 ++--
 Source/simba.random.pas                       | 34 +++++++++++++++++--
 3 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/Source/script/imports/simba/simba.import_random.pas b/Source/script/imports/simba/simba.import_random.pas
index f434ff2ac..f2c5cfcb6 100644
--- a/Source/script/imports/simba/simba.import_random.pas
+++ b/Source/script/imports/simba/simba.import_random.pas
@@ -151,7 +151,7 @@ procedure _LapeRandomModeI(const Params: PParamArray; const Result: Pointer); LA
 (*
 GaussRand
 ~~~~~~~~~
-> function GaussRand(Mean, Dev: Double): Double
+> function GaussRand(Mean, Dev: Double): Double;
 
 Generates a random gaussian/normal number.
 *)
@@ -160,6 +160,18 @@ procedure _LapeGaussRand(const Params: PParamArray; const Result: Pointer); LAPE
   PDouble(Result)^ := GaussRand(PDouble(Params^[0])^, PDouble(Params^[1])^);
 end;
 
+(*
+Randomize
+~~~~~~~~~
+> procedure Randomize;
+
+Generates a new `RandSeed`
+*)
+procedure _LapeRandomize(const Params: PParamArray); LAPE_WRAPPER_CALLING_CONV
+begin
+  BetterRandomize();
+end;
+
 procedure ImportRandom(Compiler: TSimbaScript_Compiler);
 begin
   with Compiler do
@@ -168,6 +180,8 @@ procedure ImportRandom(Compiler: TSimbaScript_Compiler);
 
     addGlobalVar(ltDouble, @RandCutoff, 'RandCutoff');
 
+    addGlobalFunc('procedure Randomize; override;', @_LapeRandomize);
+
     addGlobalFunc('function RandomCenterTPA(Amount: Integer; Box: TBox): TPointArray', @_LapeRandomCenterTPA);
     addGlobalFunc('function RandomTPA(Amount: Integer; Box: TBox): TPointArray', @_LapeRandomTPA);
 
diff --git a/Source/simba.init.pas b/Source/simba.init.pas
index b2b7eb55f..de3bd2117 100644
--- a/Source/simba.init.pas
+++ b/Source/simba.init.pas
@@ -19,7 +19,8 @@ interface
   {$IFDEF UNIX}
   cthreads,
   {$ENDIF}
-  classes, sysutils, lazlogger;
+  Classes, SysUtils,
+  simba.random;
 
 implementation
 
@@ -61,13 +62,13 @@ initialization
   LinuxInitialization();
   {$ENDIF}
 
-  Randomize();
-
   FormatSettings.ThousandSeparator := ',';
   FormatSettings.DecimalSeparator := '.';
   FormatSettings.DateSeparator := '-';
   FormatSettings.TimeSeparator := ':';
 
+  BetterRandomize();
+
 finalization
   {$IFDEF DARWIN}
   DarwinFinalization();
diff --git a/Source/simba.random.pas b/Source/simba.random.pas
index d94a3e0f0..2ba608e62 100644
--- a/Source/simba.random.pas
+++ b/Source/simba.random.pas
@@ -10,7 +10,7 @@
 interface
 
 uses
-  classes, sysutils,
+  Classes, SysUtils,
   simba.mufasatypes;
 
 function RandomCenterTPA(Amount: Integer; Box: TBox): TPointArray;
@@ -30,13 +30,16 @@ function RandomMode(Mode, Lo, Hi: Int64): Int64; overload;
 
 function GaussRand(Mean, Dev: Double): Double;
 
+procedure BetterRandomize;
+
 var
   RandCutoff: Double = 5;
 
 implementation
 
 uses
-  math;
+  Math,
+  simba.process;
 
 function nzRandom: Double;
 begin
@@ -139,5 +142,32 @@ function GaussRand(Mean, Dev: Double): Double;
   Result := Mean + Len * Cos(2 * PI * Random());
 end;
 
+{$R-}{$Q-}
+
+// https://github.com/dajobe/libmtwist/blob/master/seed.c
+procedure BetterRandomize;
+
+  procedure Mix(var A, B, C: UInt32);
+  begin
+    A -= C;  A := A xor ((C shl 4)  or (C shr (32-4)));  C += B;
+    B -= A;  B := B xor ((A shl 6)  or (A shr (32-6)));  A += C;
+    C -= B;  C := C xor ((B shl 8)  or (B shr (32-8)));  B += A;
+    A -= C;  A := A xor ((C shl 16) or (C shr (32-16))); C += B;
+    B -= A;  B := B xor ((A shl 19) or (A shr (32-19))); A += C;
+    C -= B;  C := C xor ((B shl 4)  or (B shr (32-4)));  B += A;
+  end;
+
+var
+  A, B, C: UInt32;
+begin
+  A := UInt32(GetTickCount64());
+  B := UInt32(GetProcessID());
+  C := UInt32(SimbaProcess.GetProcessRunnningTime(GetProcessID()));
+
+  Mix(A, B, C);
+
+  RandSeed := C;
+end;
+
 end.