Frezon (#9980)

* stuff i'll have to fix anyway when n2o gets merged

* everything except the finished reactions

* freon coolant reaction but with bad curve

* miasmic subsumation

* freon production

* nitrogen and diff temp scaling

* uhh meant to change that

* #

* hitting that frezon boof

Content.Server/Atmos/Reactions/FrezonCoolantReaction.cs

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+using Content.Server.Atmos.EntitySystems;
+using Content.Shared.Atmos;
+using JetBrains.Annotations;
+
+namespace Content.Server.Atmos.Reactions;
+
+/// <summary>
+///     Takes in nitrogen and frezon and cools down the surrounding area.
+/// </summary>
+[UsedImplicitly]
+public sealed class FrezonCoolantReaction : IGasReactionEffect
+{
+    public ReactionResult React(GasMixture mixture, IGasMixtureHolder? holder, AtmosphereSystem atmosphereSystem)
+    {
+        var oldHeatCapacity = atmosphereSystem.GetHeatCapacity(mixture);
+        var temperature = mixture.Temperature;
+
+        var energyModifier = 1f;
+        var scale = (temperature - Atmospherics.FrezonCoolLowerTemperature) /
+                    (Atmospherics.FrezonCoolMidTemperature - Atmospherics.FrezonCoolLowerTemperature);
+
+        if (scale > 1f)
+        {
+            // Scale energy but not frezon usage if we're in a very, very hot place
+            energyModifier = Math.Min(scale, Atmospherics.FrezonCoolMaximumEnergyModifier);
+            scale = 1f;
+        }
+
+        if (scale <= 0)
+            return ReactionResult.NoReaction;
+
+        var initialNit = mixture.GetMoles(Gas.Nitrogen);
+        var initialFrezon = mixture.GetMoles(Gas.Frezon);
+
+        var burnRate = initialFrezon * scale / Atmospherics.FrezonCoolRateModifier;
+
+        var energyReleased = 0f;
+        if (burnRate > Atmospherics.MinimumHeatCapacity)
+        {
+            var nitAmt = Math.Min(burnRate * Atmospherics.FrezonNitrogenCoolRatio, initialNit);
+            var frezonAmt = Math.Min(burnRate, initialFrezon);
+            mixture.AdjustMoles(Gas.Nitrogen, -nitAmt);
+            mixture.AdjustMoles(Gas.Frezon, -frezonAmt);
+            // TODO nitrous oxide
+            mixture.AdjustMoles(Gas.CarbonDioxide, nitAmt + frezonAmt);
+            energyReleased = burnRate * Atmospherics.FrezonCoolEnergyReleased * energyModifier;
+        }
+
+        if (energyReleased >= 0f)
+            return ReactionResult.NoReaction;
+
+        var newHeatCapacity = atmosphereSystem.GetHeatCapacity(mixture);
+        if (newHeatCapacity > Atmospherics.MinimumHeatCapacity)
+            mixture.Temperature = (temperature * oldHeatCapacity + energyReleased) / newHeatCapacity;
+
+        return ReactionResult.Reacting;
+    }
+}

Content.Server/Atmos/Reactions/FrezonProductionReaction.cs

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+using Content.Server.Atmos.EntitySystems;
+using Content.Shared.Atmos;
+using JetBrains.Annotations;
+
+namespace Content.Server.Atmos.Reactions;
+
+/// <summary>
+///     Produces frezon from oxygen and tritium, with nitrogen as a catalyst that also acts as a stopper if too much is present.
+///     Has a max temperature, but paradoxically gets more efficient the hotter it is.
+/// </summary>
+[UsedImplicitly]
+public sealed class FrezonProductionReaction : IGasReactionEffect
+{
+    public ReactionResult React(GasMixture mixture, IGasMixtureHolder? holder, AtmosphereSystem atmosphereSystem)
+    {
+        var initialN2 = mixture.GetMoles(Gas.Nitrogen);
+        var initialOxy = mixture.GetMoles(Gas.Oxygen);
+        var initialTrit = mixture.GetMoles(Gas.Tritium);
+
+        var efficiency = mixture.Temperature / Atmospherics.FrezonProductionMaxEfficiencyTemperature;
+        var loss = 1 - efficiency;
+
+        // Less N2 is required the more efficient it is.
+        var minimumN2 = (initialOxy + initialTrit) / (Atmospherics.FrezonProductionNitrogenRatio * efficiency);
+
+        if (initialN2 < minimumN2)
+            return ReactionResult.NoReaction;
+
+        var oxyConversion = initialOxy / Atmospherics.FrezonProductionConversionRate;
+        var tritConversion = initialTrit / Atmospherics.FrezonProductionConversionRate;
+        var total = oxyConversion + tritConversion;
+
+        mixture.AdjustMoles(Gas.Oxygen, -oxyConversion);
+        mixture.AdjustMoles(Gas.Tritium, -tritConversion);
+        mixture.AdjustMoles(Gas.Frezon, total * efficiency);
+        mixture.AdjustMoles(Gas.Nitrogen, total * loss);
+
+        return ReactionResult.Reacting;
+    }
+}

Content.Server/Atmos/Reactions/MiasmicSubsumationReaction.cs

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+using Content.Server.Atmos.EntitySystems;
+using Content.Shared.Atmos;
+using JetBrains.Annotations;
+
+namespace Content.Server.Atmos.Reactions;
+
+/// <summary>
+///     Converts frezon into miasma when the two come into contact. Does not occur at very high temperatures.
+/// </summary>
+[UsedImplicitly]
+public sealed class MiasmicSubsumationReaction : IGasReactionEffect
+{
+    public ReactionResult React(GasMixture mixture, IGasMixtureHolder? holder, AtmosphereSystem atmosphereSystem)
+    {
+        var initialMiasma = mixture.GetMoles(Gas.Miasma);
+        var initialFrezon = mixture.GetMoles(Gas.Frezon);
+
+        var convert = Math.Min(Math.Min(initialFrezon, initialMiasma), Atmospherics.MiasmicSubsumationMaxConversionRate);
+
+        mixture.AdjustMoles(Gas.Miasma, convert);
+        mixture.AdjustMoles(Gas.Frezon, -convert);
+
+        return ReactionResult.Reacting;
+    }
+}