speed up production if multiple buildings of the same type exist

OpenRA.Mods.RA/Player/ClassicProductionQueue.cs

@@ -8,6 +8,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.RA.Buildings;
@@ -71,5 +72,30 @@ namespace OpenRA.Mods.RA
 			}
 			return false;
 		}
+
+		public override int GetBuildTime(String unitString)
+		{
+			var unit = Rules.Info[unitString];
+			if (unit == null || ! unit.Traits.Contains<BuildableInfo>())
+				return 0;
+
+			if (self.World.LobbyInfo.GlobalSettings.AllowCheats && self.Owner.PlayerActor.Trait<DeveloperMode>().FastBuild) return 0;
+			var cost = unit.Traits.Contains<ValuedInfo>() ? unit.Traits.Get<ValuedInfo>().Cost : 0;
+
+			var selfsameBuildings = self.World.ActorsWithTrait<Production>()
+				.Where(p => p.Trait.Info.Produces.Contains(unit.Traits.Get<BuildableInfo>().Queue))
+				.Where(p => p.Actor.Owner == self.Owner).ToArray();
+
+			var speedUp = 1 - (selfsameBuildings.First().Trait.Info.SpeedUp * (selfsameBuildings.Count() - 1))
+				.Clamp(0, selfsameBuildings.First().Trait.Info.MaxSpeedUp);
+
+			var time = cost
+				* Info.BuildSpeed
+				* (25 * 60) /* frames per min */
+				* speedUp
+				 / 1000;
+
+			return (int) time;
+		}
 	}
 }

OpenRA.Mods.RA/Player/ProductionQueue.cs

@@ -253,7 +253,7 @@ namespace OpenRA.Mods.RA
 			}
 		}
 
-		public int GetBuildTime(String unitString)
+		virtual public int GetBuildTime(String unitString)
 		{
 			var unit = Rules.Info[unitString];
 			if (unit == null || ! unit.Traits.Contains<BuildableInfo>())
@@ -263,7 +263,7 @@ namespace OpenRA.Mods.RA
 			var cost = unit.Traits.Contains<ValuedInfo>() ? unit.Traits.Get<ValuedInfo>().Cost : 0;
 			var time = cost
 				* Info.BuildSpeed
-				* (25 * 60) /* frames per min */				/* todo: build acceleration, if we do that */
+				* (25 * 60) /* frames per min */
 				 / 1000;
 
 			if (unit.Traits.Contains<CustomBuildTimeValueInfo>())

OpenRA.Mods.RA/Production.cs

@@ -22,6 +22,9 @@ namespace OpenRA.Mods.RA
 	{
 		public readonly string[] Produces = { };
 
+		public readonly float SpeedUp = 0;
+		public readonly float MaxSpeedUp = 0;
+
 		public virtual object Create(ActorInitializer init) { return new Production(this); }
 	}