Internals alert fix and adjustment (#12517)

* add low pressure data field

* resolve CheckSeverity bug, replace logic

* add configurable low pressure threshhold

Content.Server/Atmos/Components/GasTankComponent.cs

@@ -8,9 +8,11 @@ namespace Content.Server.Atmos.Components
     public sealed class GasTankComponent : Component, IGasMixtureHolder
     {
         public const float MaxExplosionRange = 14f;
+        private const float DefaultLowPressure = 0f;
         private const float DefaultOutputPressure = Atmospherics.OneAtmosphere;
 
         public int Integrity = 3;
+        public bool IsLowPressure => (Air?.Pressure ?? 0F) <= TankLowPressure;
 
         [ViewVariables(VVAccess.ReadWrite), DataField("ruptureSound")]
         public SoundSpecifier RuptureSound = new SoundPathSpecifier("/Audio/Effects/spray.ogg");
@@ -32,6 +34,13 @@ namespace Content.Server.Atmos.Components
 
         [DataField("air")] [ViewVariables] public GasMixture Air { get; set; } = new();
 
+        /// <summary>
+        ///     Pressure at which tank should be considered 'low' such as for internals.
+        /// </summary>
+        [DataField("tankLowPressure")]
+        [ViewVariables]
+        public float TankLowPressure { get; set; } = DefaultLowPressure;
+
         /// <summary>
         ///     Distributed pressure.
         /// </summary>

Content.Server/Body/Systems/InternalsSystem.cs

@@ -208,10 +208,10 @@ public sealed class InternalsSystem : EntitySystem
     {
         if (component.BreathToolEntity == null || !AreInternalsWorking(component)) return 2;
 
-        // What we are checking here is if there is more moles in tank than we need.
+        // If pressure in the tank is below low pressure threshhold, flash warning on internals UI
         if (TryComp<GasTankComponent>(component.GasTankEntity, out var gasTank)
-            && (gasTank.OutputPressure * Atmospherics.BreathVolume / Atmospherics.R * gasTank.Air.Temperature) >= gasTank.Air.TotalMoles)
-            return 0;
+            && gasTank.IsLowPressure)
+                return 0;
 
         return 1;
     }

Resources/Prototypes/Entities/Objects/Tools/gas_tanks.yml

@@ -1,4 +1,4 @@
-- type: entity
+- type: entity
   abstract: true
   parent: BaseItem
   id: GasTankBase
@@ -44,6 +44,7 @@
     air:
       volume: 70
       temperature: 293.15
+    tankLowPressure: 30.0
   - type: Clothing
     sprite: Objects/Tanks/oxygen.rsi
     slots: