What is the algorithm used for GMS 2.x Random Number Generator?

[Kruno]

I am curious if it is using the 1980's LCG algorithm, or something akin to PCG32 algorithm (Permuted Congruential Generator).

 

[YellowAfterlife]

If you have a HTML5 GM module, you may compile in debug mode and then inspect the generated code in JS debugger - the exact algorithm name is not known, but the state is 128-bit (IIRC) and there's a handful of bit operations involved, which puts it into "definitely not LCG" bracket.

 

[Kruno]

Just as a precaution I have implemented PCG. I am writing simulations and this is mission critical for me. I have used poor RNG in the past and it cost me some serious time.

 

[Yal]

Just as a side note, I've seen disclaimers thrown around that the same seed gives different sequences on different targets, so the HTML5 source might be different from the RNG used on desktop targets, and so on, so inspecting one target's source tells you nothing about the others, and if you want consistent set-seed RNG between different ports of your game, you can't rely on the built-in system. Not sure if this was unified in GMS2 or is still a valid caveat. Okay, GMS2 manual still has the disclaimer.

 

[Kruno]

I don't mean to be annoying but does anyone know any more details? I am only concerned about GM:S 2 on the Desktop (win32).

Thanks.

 

[Nocturne]

It's the WELL512a algorithm you can see discussed here: https://stackoverflow.com/questions/1046714/what-is-a-good-random-number-generator-for-a-game
Actual code: http://www.iro.umontreal.ca/~panneton/well/WELL512a.c

 

[Sam (Deleted User)]

It's the WELL512a algorithm you can see discussed here: https://stackoverflow.com/questions/1046714/what-is-a-good-random-number-generator-for-a-game
Actual code: http://www.iro.umontreal.ca/~panneton/well/WELL512a.c

Thanks Nocturne! I know someone who had the exact same question who I'll be able to pass this on to.

 

[Kruno]

It's the WELL512a algorithm you can see discussed here: https://stackoverflow.com/questions/1046714/what-is-a-good-random-number-generator-for-a-game
Actual code: http://www.iro.umontreal.ca/~panneton/well/WELL512a.c

Thank you very much.