GameCult/Aetheria
Watch
9
0
Fork
You've already forked Aetheria
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

SimulationDice: fmix32 moves out of FireControl, with the structured per-zone dice stream

Browse source 
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
This commit is contained in:
Meta Vens 2026-10-07 14:52:10 +02:00
commit 9116946874
3 changed files with 48 additions and 18 deletions
Download patch file Download diff file Expand all files Collapse all files

20
Assets/Scripts/ServerShared/FireControl.cs
View file

@ -667,22 +667,6 @@ public static class FireControl
// so whether a gated shot draws is unobservable from anywhere. The claim this comment used to make is
// gone with the stream it was about, and the test that asserted it became vacuous the same moment; what
// replaced it pins the live rule instead (combat touches no shared stream, on any path).
// 9.1 (docs/fire-control-cut.md): fmix32, MurmurHash3's 32-bit finalizer -- xor-shift, multiply,
// xor-shift, multiply, xor-shift. Diffuses a structured seed (here, a zone seed XORed with a small,
// low-bits-only ShotId) across every bit before the first xorshift draw reads it, so two seeds that
// differ only in ShotId's low bits still land on uncorrelated first outputs. Caller-side mixing only
// -- CultMath.Random itself is unchanged (see Commit's own note on why that follow-up is a separate
// CultLib cut).
private static uint MixSeed(uint seed)
{
seed ^= seed >> 16;
seed *= 0x85ebca6bu;
seed ^= seed >> 13;
seed *= 0xc2b2ae35u;
seed ^= seed >> 16;
return seed;
}
// Cut 12.2 (docs/fire-control-cut.md, "Bearing timing"): steps 1-5. Everything the shooter decided is
// frozen in `shot` (R10); everything the target is doing -- position (deviation) and now also facing
// (bearing) -- is read live, here, at the commit tick. The Cut 7 guard extends to cover the new factors:
@ -722,11 +706,11 @@ public static class FireControl
// round for NextFloat's first call, and one round does not diffuse a seed that differs from its
// neighbours only in ShotId's low bits. Unmixed, every zone's first draw was a near-constant
// function of ShotId (measured span ~0.125), making a shot a step function of p fixed at zone
// creation, not a roll (Soul C1). MixSeed is a standard fmix32 finalizer (MurmurHash3): this is
// creation, not a roll (Soul C1). SimulationDice.Mix is a standard fmix32 finalizer (MurmurHash3): this is
// a caller's obligation, not a CultMath defect -- seeding xorshift with a structured value and
// drawing once is the documented way to get a correlated first output, and a follow-up to give
// CultMath.Random a mixed-seed entry point of its own is recorded for a separate CultLib cut.
var random = new Random(MixSeed((zone.CombatSeed * 2654435761u) ^ (uint) shot.ShotId | 1u));
var random = new Random(SimulationDice.Mix((zone.CombatSeed * 2654435761u) ^ (uint) shot.ShotId | 1u));
var p = CommitProbability(shot, now, out var sil);
var hit = p > 0f && random.NextFloat() < p;