Fix wind turbine desync

[Tick-git]

Label: 1.6, Desync

Tested only on dev.

Issue:

Reported by two people on discord:

In RimWorld 1.6 desyncs occur whenever electrical devices - like ACs connected directly to wind turbines - lose power or regain power. The power state change seems to consistently trigger desyncs during multiplayer.

Fix:

Changes wind speed calculation to be equal on all clients.

This patch replaces object.GetHashCode() with a deterministic hash based on map.Tile when in multiplayer.

In version 1.5, this.map.Tile was used instead of this.map.GetHashCode().

In version 1.6, map.Tile is no longer an int, but a PlanetTile object. However, it can still be implicitly converted to an int.

Using GetHashCode() in 1.6 introduces wind speed randomness across game loads. This patch ensures consistency between all clients in multiplayer, but it removes the randomness.

Tested

• Wind turbine output is equal across all clients.
• Connected many consumers to a wind turbine, causing them to lose and regain power intermittently.
• Created a new settlement in the session to test whether the new wind manager calculates wind speed deterministically across clients as well.

Method in 1.6

private float BaseWindSpeedAt(int ticksAbs)
{
    if (this.windNoise == null)
    {
        int seed = Gen.HashCombineInt(this.map.GetHashCode(), 122049541) ^ Find.World.info.Seed;
        this.windNoise = new Perlin(3.9999998989515007E-05, 2.0, 0.5, 4, seed, QualityMode.Medium);
        this.windNoise = new ScaleBias(1.5, 0.5, this.windNoise);
        this.windNoise = new Clamp((double)WindManager.WindSpeedRange.min, (double)WindManager.WindSpeedRange.max, this.windNoise);
    }
    return (float)this.windNoise.GetValue((double)ticksAbs, 0.0, 0.0);
}

Method in 1.5

private float BaseWindSpeedAt(int ticksAbs)
{
    if (this.windNoise == null)
    {
        int seed = Gen.HashCombineInt(this.map.Tile, 122049541) ^ Find.World.info.Seed;
        this.windNoise = new Perlin(3.9999998989515007E-05, 2.0, 0.5, 4, seed, QualityMode.Medium);
        this.windNoise = new ScaleBias(1.5, 0.5, this.windNoise);
        this.windNoise = new Clamp((double)WindManager.WindSpeedRange.min, (double)WindManager.WindSpeedRange.max, this.windNoise);
    }
    return (float)this.windNoise.GetValue((double)ticksAbs, 0.0, 0.0);
}

[notfood]

This is a bug that could be reported to Ludeon, feels like a mistake on their part.