Give reaction prototypes a priority (nerf ClF3 + smoke) (#7268)

Content.Shared/Chemistry/Reaction/ReactionPrototype.cs

@@ -15,7 +15,7 @@ namespace Content.Shared.Chemistry.Reaction
     /// Prototype for chemical reaction definitions
     /// </summary>
     [Prototype("reaction")]
-    public sealed class ReactionPrototype : IPrototype
+    public sealed class ReactionPrototype : IPrototype, IComparable<ReactionPrototype>
     {
         [ViewVariables]
         [DataField("id", required: true)]
@@ -67,6 +67,33 @@ namespace Content.Shared.Chemistry.Reaction
         /// enough reactants, the reaction does not occur. Useful for spawn-entity reactions (e.g. creating cheese).
         /// </summary>
         [DataField("quantized")] public bool Quantized = false;
+
+        /// <summary>
+        /// Determines the order in which reactions occur. This should used to ensure that (in general) descriptive /
+        /// pop-up generating and explosive reactions occur before things like foam/area effects.
+        /// </summary>
+        [DataField("priority")]
+        public int Priority;
+
+        /// <summary>
+        ///     Comparison for creating a sorted set of reactions. Determines the order in which reactions occur.
+        /// </summary>
+        public int CompareTo(ReactionPrototype? other)
+        {
+            if (other == null)
+                return -1;
+
+            if (Priority != other.Priority)
+                return other.Priority - Priority;
+
+            // Prioritize reagents that don't generate products. This should reduce instances where a solution
+            // temporarily overflows and discards products simply due to the order in which the reactions occurred.
+            // Basically: Make space in the beaker before adding new products.
+            if (Products.Count != other.Products.Count)
+                return Products.Count - other.Products.Count;
+
+            return ID.CompareTo(other.ID);
+        }
     }
 
     /// <summary>

Content.Shared/Chemistry/Reaction/SharedChemicalReactionSystem.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using Content.Shared.Administration;
 using Content.Shared.Administration.Logs;
 using Content.Shared.Chemistry.Components;
@@ -211,44 +212,56 @@ namespace Content.Shared.Chemistry.Reaction
         ///     Removes the reactants from the solution, then returns a solution with all products.
         ///     WARNING: Does not trigger reactions between solution and new products.
         /// </summary>
-        private bool ProcessReactions(Solution solution, EntityUid owner, [MaybeNullWhen(false)] out Solution productSolution)
+        private bool ProcessReactions(Solution solution, EntityUid owner, FixedPoint2 maxVolume, SortedSet<ReactionPrototype> reactions)
         {
-            foreach(var reactant in solution.Contents)
+            HashSet<ReactionPrototype> toRemove = new();
+            Solution? products = null;
+
+            // attempt to perform any applicable reaction
+            foreach (var reaction in reactions)
             {
-                if (!_reactions.TryGetValue(reactant.ReagentId, out var reactions))
-                    continue;
-
-                foreach(var reaction in reactions)
+                if (!CanReact(solution, reaction, out var unitReactions))
                 {
-                    if (!CanReact(solution, reaction, out var unitReactions))
-                        continue;
-
-                    productSolution = PerformReaction(solution, owner, reaction, unitReactions);
-                    return true;
+                    toRemove.Add(reaction);
+                    continue;
                 }
+
+                products = PerformReaction(solution, owner, reaction, unitReactions);
+                break;
             }
 
-            productSolution = null;
-            return false;
+            // did any reaction occur?
+            if (products == null)
+                return false; ;
+
+            // Remove any reactions that were not applicable. Avoids re-iterating over them in future.
+            reactions.Except(toRemove);
+
+            if (products.TotalVolume <= 0)
+                return true;
+
+            // remove excess product
+            // TODO spill excess?
+            var excessVolume = solution.TotalVolume + products.TotalVolume - maxVolume;
+            if (excessVolume > 0)
+                products.RemoveSolution(excessVolume);
+
+            // Add any reactions associated with the new products. This may re-add reactions that were already iterated
+            // over previously. The new product may mean the reactions are applicable again and need to be processed.
+            foreach (var reactant in products.Contents)
+            {
+                if (_reactions.TryGetValue(reactant.ReagentId, out var reactantReactions))
+                    reactions.UnionWith(reactantReactions);
+            }
+
+            solution.AddSolution(products);
+            return true;
         }
 
         /// <summary>
         ///     Continually react a solution until no more reactions occur.
         /// </summary>
-        public void FullyReactSolution(Solution solution, EntityUid owner)
-        {
-            for (var i = 0; i < MaxReactionIterations; i++)
-            {
-                if (!ProcessReactions(solution, owner, out var products))
-                    return;
-
-                if (products.TotalVolume <= 0)
-                    return;
-
-                solution.AddSolution(products);
-            }
-            Logger.Error($"{nameof(Solution)} {owner} could not finish reacting in under {MaxReactionIterations} loops.");
-        }
+        public void FullyReactSolution(Solution solution, EntityUid owner) => FullyReactSolution(solution, owner, FixedPoint2.MaxValue);
 
         /// <summary>
         ///     Continually react a solution until no more reactions occur, with a volume constraint.
@@ -256,24 +269,22 @@ namespace Content.Shared.Chemistry.Reaction
         /// </summary>
         public void FullyReactSolution(Solution solution, EntityUid owner, FixedPoint2 maxVolume)
         {
+            // construct the initial set of reactions to check.
+            SortedSet<ReactionPrototype> reactions = new();
+            foreach (var reactant in solution.Contents)
+            {
+                if (_reactions.TryGetValue(reactant.ReagentId, out var reactantReactions))
+                    reactions.UnionWith(reactantReactions);
+            }
+
+            // Repeatedly attempt to perform reactions, ending when there are no more applicable reactions, or when we
+            // exceed the iteration limit.
             for (var i = 0; i < MaxReactionIterations; i++)
             {
-                if (!ProcessReactions(solution, owner, out var products))
+                if (!ProcessReactions(solution, owner, maxVolume, reactions))
                     return;
-
-                if (products.TotalVolume <= 0)
-                    return;
-
-                var totalVolume = solution.TotalVolume + products.TotalVolume;
-                var excessVolume = totalVolume - maxVolume;
-
-                if (excessVolume > 0)
-                {
-                    products.RemoveSolution(excessVolume); //excess product is deleted to fit under volume limit
-                }
-
-                solution.AddSolution(products);
             }
+
             Logger.Error($"{nameof(Solution)} {owner} could not finish reacting in under {MaxReactionIterations} loops.");
         }
     }

Resources/Prototypes/Recipes/Reactions/chemicals.yml

@@ -81,6 +81,7 @@
 - type: reaction
   id: PotassiumExplosion
   impact: High
+  priority: 20
   reactants:
     Water:
       amount: 1
@@ -98,6 +99,7 @@
 
 - type: reaction
   id: Smoke
+  priority: 10
   impact: High
   reactants:
     Phosphorus:
@@ -121,6 +123,7 @@
 
 - type: reaction
   id: Foam
+  priority: 10
   impact: High
   reactants:
     Fluorosurfactant:
@@ -146,6 +149,7 @@
 - type: reaction
   id: IronMetalFoam
   impact: High
+  priority: 10
   reactants:
     Iron:
       amount: 3
@@ -172,6 +176,7 @@
 - type: reaction
   id: AluminiumMetalFoam
   impact: High
+  priority: 10
   reactants:
     Aluminium:
       amount: 3

Resources/Prototypes/Recipes/Reactions/pyrotechnic.yml

@@ -30,6 +30,7 @@
 
 - type: reaction
   id: ChlorineTrifluoride
+  priority: 20
   reactants:
     Chlorine:
       amount: 1