Show other speso colours, add larger denominations (Frontier#1496) (#37030)

Content.Client/Stack/StackSystem.cs

@@ -66,10 +66,60 @@ namespace Content.Client.Stack
             if (!_appearanceSystem.TryGetData<bool>(uid, StackVisuals.Hide, out var hidden, args.Component))
                 hidden = false;
 
+            if (comp.LayerFunction != StackLayerFunction.None)
+                ApplyLayerFunction((uid, comp), ref actual, ref maxCount);
+
             if (comp.IsComposite)
                 _counterSystem.ProcessCompositeSprite(uid, actual, maxCount, comp.LayerStates, hidden, sprite: args.Sprite);
             else
                 _counterSystem.ProcessOpaqueSprite(uid, comp.BaseLayer, actual, maxCount, comp.LayerStates, hidden, sprite: args.Sprite);
         }
+
+        /// <summary>
+        /// Adjusts the actual and maxCount to change how stack amounts are displayed.
+        /// </summary>
+        /// <param name="ent">The entity considered.</param>
+        /// <param name="actual">The actual number of items in the stack. Altered depending on the function to run.</param>
+        /// <param name="maxCount">The maximum number of items in the stack. Altered depending on the function to run.</param>
+        /// <returns>Whether or not a function was applied.</returns>
+        private bool ApplyLayerFunction(Entity<StackComponent> ent, ref int actual, ref int maxCount)
+        {
+            switch (ent.Comp.LayerFunction)
+            {
+                case StackLayerFunction.Threshold:
+                    if (TryComp<StackLayerThresholdComponent>(ent, out var threshold))
+                    {
+                        ApplyThreshold(threshold, ref actual, ref maxCount);
+                        return true;
+                    }
+                    break;
+            }
+            // No function applied.
+            return false;
+        }
+
+        /// <summary>
+        /// Selects which layer a stack applies based on a list of thresholds.
+        /// Each threshold passed results in the next layer being selected.
+        /// </summary>
+        /// <param name="comp">The threshold parameters to apply.</param>
+        /// <param name="actual">The number of items in the stack. Will be set to the index of the layer to use.</param>
+        /// <param name="maxCount">The maximum possible number of items in the stack. Will be set to the number of selectable layers.</param>
+        private static void ApplyThreshold(StackLayerThresholdComponent comp, ref int actual, ref int maxCount)
+        {
+            // We must stop before we run out of thresholds or layers, whichever's smaller. 
+            maxCount = Math.Min(comp.Thresholds.Count + 1, maxCount);
+            var newActual = 0;
+            foreach (var threshold in comp.Thresholds)
+            {
+                //If our value exceeds threshold, the next layer should be displayed.
+                //Note: we must ensure actual <= MaxCount.
+                if (actual >= threshold && newActual < maxCount)
+                    newActual++;
+                else
+                    break;
+            }
+            actual = newActual;
+        }
     }
 }