AGS 4: Script API: add eRound options and new Maths.Random()

[ivan-mogilko]

Resolve #1983, #2683

Contents:

1. Expands eRound option with 2 new modes:

   • eRoundTowardsZero - rounds towards a closest integer less by magnitude (absolute value);
   • eRoundAwayFromZero - rounds towards a closest integer larger by magnitude (absolute value);

2. Add float Maths.Round(float, RoundDirection) - which rounds a float value to another float value (without making it int).

3. Add Maths.Random(limit), a proper variant of Random, which treats limit as an upper exclusive boundary. So Maths.Random(10) would choose a number between 0 and 9, but never 10.

4. Add Maths.RandomFloat() which produces a float in range [0.0, 1.0) (excluding 1.0).

[AlanDrake]

I've never seen a round direction in random algorithms, but I can see it could come in handy. sorry, I misread

The only weakness is relying on rand(), we should perhaps implement a xoshiro/xoroshiro/lehmer/PCG algorithm, which are fast and have better statistical distributions (could be another PR).

[messengerbag]

Thanks, that's grand, @ivan-mogilko!

Only thing is Maths.RandomFloat(), which – just as with Maths.Random() – I think should exclude the upper limit, i.e. [0.0, 1.0). This would be consistent with Math.random() in Java and Javascript, C#'s Random.NextDouble(), Python's random.random(), etc.

[ivan-mogilko]

Only thing is Maths.RandomFloat(), which – just as with Maths.Random() – I think should exclude the upper limit, i.e. [0.0, 1.0).

I was not sure if it should or not, but forgot to check existing examples.