[Solved] ModuleTestSubject Question

[WololoW]

So when you look at some stock parts from the update, you will find that there is a new Module, ModuleTestSubject.

I was wondering how exactly the environments = 15 argument works in this code here,

MODULE
{
    name = ModuleTestSubject

    // nowhere: 0, srf: 1, ocean: 2, atmo: 4, space: 8
    environments = 15

    useStaging = True
    useEvent = False
}

As you see, the comment suggests that there are 5 options, but then directly below it, a 6th, not before mentioned, option is chosen.

Basically: What does "environments = 15" do, and why isnt it commented about?

Thanks in advance!

Edited July 23, 2014 by WololoW

[Justin Kerbice]

it's a bit mask ie in binary it is :

00000 = 0

00001 = 1

00010 = 2

00100 = 4

01000 = 8

01111 = 15 = 8 + 4 + 2 + 1

they choose the easy way to do it by considering only power of 2, including 0 (0, 1, 2, 4, 8... 1 = 2^0, 2 = 2^1, ... with ^ power operant) so they can check a bit is set by

if flags & 00001 = srf

(00111 & 00001 = 00001 binary and)

this is far more efficient (space and time) than numeric mask with things like enum or preprocessor constants, depending on language features.

[WololoW]

Okay, I was wondering if that was the case. Much appreciated!