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* fixed RandSeed bug

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This commit is contained in:
Jonas Maebe 1998-10-12 22:11:28 +00:00
parent ccd97bbec9
commit 3aca7519c9
1 changed files with 19 additions and 14 deletions
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33
rtl/inc/system.inc
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@ -35,7 +35,6 @@ const
{ Random / Randomize constants }
OldRandSeed : Longint = 0;
InitialSeed : Boolean = TRUE;
Seed1 : Longint = 0;
Seed2 : Cardinal = 0;
Seed3 : Cardinal = 0;
@ -180,24 +179,25 @@ Function Random : Real;
var
ReturnValue : Real;
begin
if (InitialSeed) OR ((RandSeed <> OldRandSeed) AND NOT InitialSeed) then
if (InitialSeed) OR ((RandSeed <> OldRandSeed) AND (NOT InitialSeed)) then
Begin
OldRandSeed:=RandSeed;
{ This is a pretty complicated affair }
{ Initially we must call UseSeed when RandSeed is initalized }
{ We must also call UseSeed each time RandSeed is reinitialized }
{ DO NOT CHANGE THE ORDER OF DECLARATIONS IN THIS BLOCK }
{ UNLESS YOU WANT RANDON TO CRASH OF COURSE (CEC) }
InitialSeed:=FALSE;
UseSeed(Randseed);
OldRandSeed:=RandSeed;
UseSeed(RandSeed);
end;
Inc(Seed1);
Seed1 := (Seed1 * 706) mod 500009;
Inc(RandSeed);
RandSeed := (RandSeed * 706) mod 500009;
OldRandSeed:=RandSeed;
INC(Seed2);
Seed2 := (Seed2 * 774) MOD 600011;
INC(Seed3);
Seed3 := (Seed3 * 871) MOD 765241;
ReturnValue := Seed1/500009.0 +
ReturnValue := RandSeed/500009.0 +
Seed2/600011.0 +
Seed3/765241.0;
Random := frac(ReturnValue);
@ -206,26 +206,27 @@ end;
Function Random(l : Longint) : Longint;
begin
if (InitialSeed) OR ((RandSeed <> OldRandSeed) AND NOT InitialSeed) then
if (InitialSeed) OR ((RandSeed <> OldRandSeed) AND (NOT InitialSeed)) then
Begin
OldRandSeed:=RandSeed;
{ This is a pretty complicated affair }
{ Initially we must call UseSeed when RandSeed is initalized }
{ We must also call UseSeed each time RandSeed is reinitialized }
{ DO NOT CHANGE THE ORDER OF DECLARATIONS IN THIS BLOCK }
{ UNLESS YOU WANT RANDON TO CRASH OF COURSE (CEC) }
InitialSeed:=FALSE;
OldRandSeed:=RandSeed;
UseSeed(Randseed);
end;
Inc(Seed1);
Seed1 := (Seed1 * 998) mod 1000003;
Random := Seed1 mod l;
Inc(RandSeed);
RandSeed := (RandSeed * 998) mod 1000003;
OldRandSeed:=RandSeed;
Random := RandSeed mod l;
end;
Procedure UseSeed(seed : Longint);
begin
Seed1 := seed mod 1000003;
randseed := seed mod 1000003;
Seed2 := (Random(65000) * Random(65000)) mod 600011;
Seed3 := (Random(65000) * Random(65000)) mod 765241;
end;
@ -475,12 +476,16 @@ end;
{
$Log$
Revision 1.38 1998-10-12 12:43:37 florian
Revision 1.39 1998-10-12 22:11:28 jonas
* fixed RandSeed bug
Revision 1.38 1998/10/12 12:43:37 florian
* made FPC_HANDLEERROR public
Revision 1.37 1998/10/07 11:40:08 jonas
* changed seed2 and seed3 to cardinal to prevent overflow
Revision 1.36 1998/10/05 12:32:51 peter
+ assert() support