DayNightSystem¶

DayNightSystem


Phase · priority	Environment · 5
Reads	`world_time` (via `ctx.WorldTime`), `temperature` on `Outdoor` locations
Writes	`ambient_temperature` on the World node; `temperature` on `Outdoor` locations
Settings	`BaseDayTemperature` 15 °C, `TemperatureAmplitude` 10 °C, `OutdoorEquilibrationPerHour` 0.4
Status	designed · Phase 1 (#34)
PLAN	§11.4, §5.5
Player	Time

Computes the ambient temperature from the clock and pulls outdoor places toward it. It does not advance time: the engine owns world_time (an earlier draft had this system write it, which stopped the clock whenever the sun was toggled off).

var minuteOfDay = ctx.WorldTime % 1440;
var ambient = baseTemp + amp * DeterministicMath.Sin(2 * MathF.PI * minuteOfDay / 1440f);   // never Math.Sin
yield return new SetAttributeIntent(world, "ambient_temperature", ambient);

foreach (var outdoor in view.NodesWithComponent("Outdoor"))
{
    var temp  = view.GetOrDefault(outdoor, "temperature", ambient);
    var delta = (ambient - temp) * s.OutdoorEquilibrationPerHour / ctx.Hours(1);
    if (Math.Abs(delta) > 0.1f) yield return new DeltaAttributeIntent(outdoor, "temperature", delta);
}

Midday ≈ 25 °C, midnight ≈ 5 °C at defaults. Buildings (no Outdoor) are left to HeatSystem's slower equilibration, which is why they buffer the night.

Hot-toggle: off, ambient_temperature stays at its last value and the day stops changing; time itself continues. Trace: one ambient_temperature set per tick; outdoor deltas carry no Inputs (the cause is the clock).

History¶

Phase	Change
1	Introduced; no longer advances `world_time`; equilibration rate per hour; `DeterministicMath.Sin`.