Talk:GetRandomPercent
Is this similar to Morrowind's Random100 function, or can it be used in the same manner? The Imperial Dragon 12:58, 11 June 2006 (EDT)
Random100 (as one word) in Morrowind was a global that was set to 0-100 once per frame (in the script "Main")
set variable to GetRandomPercent
in Oblivion is the same as
set variable to Random 100
in Morrowind and will return a new random number ranging from 0-99 whenever you call it.
--JOG 13:40, 11 June 2006 (EDT)
I see, thank you. The Imperial Dragon 13:44, 11 June 2006 (EDT)
JOG 17:33, 29 July 2006 (EDT): Here's the math behind the first example:
short dice set dice to 1 + 0.06 * GetRandompercent
int(1 + 0.06 * 00) = int(1 + 0.00) = int(1.00) = 1
int(1 + 0.06 * 16) = int(1 + 0.96) = int(1.96) = 1 => Chance: 17%
int(1 + 0.06 * 17) = int(1 + 1.02) = int(2.02) = 2
int(1 + 0.06 * 33) = int(1 + 1.98) = int(2.98) = 2 => Chance: 17%
int(1 + 0.06 * 34) = int(1 + 2.02) = int(3.02) = 3
int(1 + 0.06 * 49) = int(1 + 2.94) = int(3.94) = 3 => Chance: 16%
int(1 + 0.06 * 50) = int(1 + 3.00) = int(4.00) = 4
int(1 + 0.06 * 66) = int(1 + 3.96) = int(4.96) = 4 => Chance: 17%
int(1 + 0.06 * 67) = int(1 + 4.02) = int(5.02) = 5
int(1 + 0.06 * 83) = int(1 + 4.98) = int(5.98) = 5 => Chance: 17%
int(1 + 0.06 * 84) = int(1 + 5.04) = int(6.04) = 6
int(1 + 0.06 * 99) = int(1 + 5.94) = int(6.94) = 6 => Chance: 16%
short dice set dice to 6/99 * GetRandompercent
Is the loaded variant and returns this:
int(6/99 * 00) = int(0.00) = 0
int(6/99 * 16) = int(0.97) = 0 => Chance: 17%
int(5/99 * 17) = int(1.03) = 1
int(5/99 * 32) = int(1.94) = 1 => Chance: 16%
int(5/99 * 33) = int(2.00) = 2
int(5/99 * 49) = int(2.97) = 2 => Chance: 17%
int(5/99 * 50) = int(3.03) = 3
int(5/99 * 65) = int(3.94) = 3 => Chance: 16%
int(5/99 * 66) = int(4.00) = 4
int(5/99 * 82) = int(4.97) = 4 => Chance: 17%
int(5/99 * 83) = int(5.03) = 5
int(5/99 * 98) = int(5.94) = 5 => Chance: 16%
int(5/99 * 99) = int(6.00) = 6 => Chance: 1%
Seems to me that for Random Numbers up to 50 you can use this Syntax:
short var Set var to ( GetRandomPercent % <2..50> ) + 1
Where "Percent Sign" is the Modulus Operator...
Should effectively give every value 2 thru 50 an equal chance... Dejunai 13:38, 31 August 2006 (EDT)
- Hehe, don't betray all the secrets of the "cryptic" coders :)--JOG 14:02, 31 August 2006 (EDT)
Algorithm
Here's the hex of the function
call sub_47DDA0; returns system time? calls GetSystemTimeAsFileTime mov edi, eax mov eax, 0AE147AE1h; or some other constant imul edi sar edx, 5 mov eax, edx shr eax, 1Fh add eax, edx imul eax, 64h add edi, eax
From Ian Patt "That function is a wrapper around MS' stdlib rand that calls srand(time(NULL)) if it hasn't been seeded yet. It only uses the system timer once. The rest of the code is just some modular arithmetic done in fixed point."--Haama 13:42, 25 May 2008 (EDT)