Developer API

Verified against Sable 2.0.5 on Minecraft 1.21.1 (NeoForge 21.1.236). Package: com.radaeli.createaeronauticseasypressurecurve.

How it works

Sable evaluates air pressure on every call (DimensionPhysicsData.getAirPressure, which is basePressure × pressureFunction(y)) and caches nothing. The mod:

1. keeps a copy of the datapack's dimension physics (the baseline);
2. rebuilds Sable's map as baseline plus the saved overrides whenever a curve changes, and sends it to every player;
3. after a datapack reload, captures the new baseline and reapplies the overrides before Sable's own sync (OnDatapackSyncEvent at HIGHEST priority), so the packet Sable sends already carries them.

An override replaces only pressure_function and sets base_pressure to 1.0, so a point's value is the real pressure. Overrides are saved in a SavedData named create_aeronautics_easy_pressure_curve, in the overworld's data storage.

PressureCurveService

Method	Side	Description
Optional<PressureCurve> getOverride(MinecraftServer, ResourceKey<Level>)	server	The saved override, if any.
PressureCurve getEffective(Level)	both	The curve in force, with base_pressure folded into the values. On the client it reads what Sable synced.
PressureCurve getDatapackCurve(ServerLevel)	server	The datapack (or Sable default) curve, ignoring any override.
double sample(Level, double altitude)	both	Pressure at an altitude, as Sable computes it.
void set(MinecraftServer, ResourceKey<Level>, PressureCurve)	server	Saves the override, rebuilds Sable's map and sends it to all players.
void reset(MinecraftServer, ResourceKey<Level>)	server	Removes the override and goes back to the datapack.

set and reset can be called from any thread; off the server thread the work is queued onto it.

import com.radaeli.createaeronauticseasypressurecurve.PressureCurveService;
import com.radaeli.createaeronauticseasypressurecurve.curve.PressureCurve;
import com.radaeli.createaeronauticseasypressurecurve.curve.PressureCurvePoint;
import java.util.List;
import net.minecraft.server.MinecraftServer;
import net.minecraft.world.level.Level;

void thinAir(MinecraftServer server) {
    PressureCurve curve = new PressureCurve(List.of(
            new PressureCurvePoint(0, 1.0, 0.0),
            new PressureCurvePoint(300, 0.1, 0.0)));
    PressureCurveService.set(server, Level.OVERWORLD, curve);
}

This example was checked against the API, not compiled as a separate project.

PressureCurve

A record of List<PressureCurvePoint(altitude, value, slope)>. It is always valid: 1 to 64 points, finite numbers, value >= 0 and strictly increasing altitudes (points are sorted; two on the same altitude are rejected). The constructor throws IllegalArgumentException otherwise; PressureCurve.tryCreate(List) returns a DataResult instead.

It has a JSON CODEC (an array with the same fields as a Sable pressure_function) and a STREAM_CODEC. withPoint, withoutPoint(index) and scaled(factor) return new curves, and toSable() / fromSable(...) convert to and from Sable's BezierResourceFunction.

SetPressureCurvePayload

A client-to-server payload (create_aeronautics_easy_pressure_curve:set_pressure_curve) with a dimension and an optional curve; an empty curve means reset. The server ignores it unless the sender has permission level 2. Build one with SetPressureCurvePayload.set(dimension, curve) or SetPressureCurvePayload.reset(dimension).

Limits

• Only the public API above is a contract. SablePressureBridge is internal.
• The server needs the mod. On the client it is optional: the payload is registered as optional, so clients without the mod can join, and the editor tells players when the server lacks the mod.