Allow overriding individual AtmosFixMarkers with custom atmosphere

This mostly exists so freezers in a ship bought with pure nitrogen
atmosphere also actually contain a pure nitrogen atmosphere instead of
the regular freezer mix, which would immediately trigger air alarms.

As an aside: why the heck is the list of possible markers hardcoded in
fixgridatmos. You can just put the atmosphere definition on the marker
component. It's going to be fine. Nobody is running fixgridatmos in a
tight loop.

Author: isilkor

Content.Server/_NF/Shipyard/Systems/ShipyardSystem.CustomAtmos.cs

@@ -1,4 +1,3 @@
-using System.Linq;
 using Content.Server._NF.Shipyard.Components;
 using Content.Server.Atmos.Components;
 using Content.Server.Atmos.Monitor.Components;
@@ -52,10 +51,12 @@ private void ReplaceShuttleAtmosphere(
     {
         var mapGrid = shuttleGrid.Comp3!;
 
-        var mix = new GasMixture(Atmospherics.CellVolume) { Temperature = atmos.Temperature };
-        foreach (var (gas, moles) in atmos.Atmosphere)
+        var defaultAtmosMix = MakeGasMixFromDefinition(atmos);
+
+        var overrides = new Dictionary<int, GasMixture>();
+        foreach (var (marker, definition) in atmos.AtmosFixOverrides)
         {
-            mix.SetMoles(gas, moles);
+            overrides[marker] = MakeGasMixFromDefinition(definition);
         }
 
         var query = GetEntityQuery<AtmosFixMarkerComponent>();
@@ -69,15 +70,34 @@ private void ReplaceShuttleAtmosphere(
             if (_atmosphere.GetTileMixture(shuttleGrid, null, position, true) is not { Immutable: false } air)
                 continue;
 
-            // Skip any tiles with an AtmosFixMarker; they already have the correct atmosphere from FixGridAtmosCommand
-            if (_map.GetAnchoredEntities((shuttleGrid.Owner, mapGrid), position).Any(query.HasComp))
-                continue;
+            var targetMixture = defaultAtmosMix;
+
+            // Check whether we need to override any AtmosFixMarker on this tile
+            foreach (var entity in _map.GetAnchoredEntities((shuttleGrid.Owner, mapGrid), position))
+            {
+                if (query.TryComp(entity, out var marker))
+                {
+                    targetMixture = overrides.GetValueOrDefault(marker.Mode, defaultAtmosMix);
+                    break;
+                }
+            }
 
             // Replace atmosphere
-            air.CopyFrom(mix);
+            air.CopyFrom(targetMixture);
         }
     }
 
+    private static GasMixture MakeGasMixFromDefinition(AtmosphereDefinition atmos)
+    {
+        var mix = new GasMixture(Atmospherics.CellVolume) { Temperature = atmos.Temperature };
+        foreach (var (gas, moles) in atmos.Atmosphere)
+        {
+            mix.SetMoles(gas, moles);
+        }
+
+        return mix;
+    }
+
     // Assumption: There are way fewer shuttles in the game than there are top-level entities on the new grid, so
     // it's faster to look up all distro machines and check that they're on the shuttle we're setting up than going
     // through all entities on the shuttle and check that they have the atmos component

Content.Shared/_NF/Shipyard/Prototypes/ShuttleAtmospherePrototype.cs

@@ -5,20 +5,30 @@
 
 namespace Content.Shared._NF.Shipyard.Prototypes;
 
+public abstract class AtmosphereDefinition
+{
+    [DataField]
+    public float Temperature = Atmospherics.T20C;
+
+    [DataField(required: true)]
+    public Dictionary<Gas, float> Atmosphere = default!;
+}
+
 [Prototype]
-public sealed class ShuttleAtmospherePrototype : IPrototype
+public sealed class ShuttleAtmospherePrototype : AtmosphereDefinition, IPrototype
 {
     [IdDataField]
     public string ID { get; } = default!;
 
     [DataField(required: true)]
     public string Name = string.Empty;
 
+    /// <summary>
+    /// A set of atmosphere overrides for individual AtmosFixMarker tiles.
+    /// See Content.Server.Atmos.EntitySystems.AtmosphereSystem.FixGridAtmosCommand for a list of valid keys.
+    /// </summary>
     [DataField]
-    public float Temperature = Atmospherics.T20C;
-
-    [DataField(required: true)]
-    public Dictionary<Gas, float> Atmosphere = default!;
+    public Dictionary<int, ShuttleAtmosphereFixMarkerOverride> AtmosFixOverrides = [];
 
     [DataField]
     public ShuttleAtmosphereAlarms? Alarms;
@@ -27,6 +37,9 @@ public sealed class ShuttleAtmospherePrototype : IPrototype
     public List<Gas>? FilterGases;
 }
 
+[DataDefinition]
+public sealed partial class ShuttleAtmosphereFixMarkerOverride : AtmosphereDefinition;
+
 [DataDefinition]
 public sealed partial class ShuttleAtmosphereAlarms
 {

Resources/Prototypes/_NF/Shipyard/Base/atmos.yml

@@ -23,6 +23,11 @@
     gasThresholdPrototypes:
       Oxygen: voxOxygen
       Nitrogen: voxNitrogen
+  atmosFixOverrides:
+    6: # Freezer
+      temperature: 235
+      atmosphere:
+        Nitrogen: 129.64464
   filterGases:
   - Oxygen
   - CarbonDioxide