only show welding overlays when factories are producing

closes #3756

OpenRA.Mods.D2k/OpenRA.Mods.D2k.csproj

@@ -83,6 +83,7 @@
     <Compile Include="FogPaletteFromR8.cs" />
     <Compile Include="DamagedWithoutFoundation.cs" />
     <Compile Include="Render\WithBuildingPlacedOverlayInfo.cs" />
+    <Compile Include="Render\WithProductionOverlay.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <PropertyGroup>

OpenRA.Mods.D2k/Render/WithProductionOverlay.cs

@@ -0,0 +1,95 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2014 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using OpenRA.FileFormats;
+using OpenRA.Graphics;
+using OpenRA.Mods.RA.Buildings;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA.Render
+{
+	public class WithProductionOverlayInfo : ITraitInfo, Requires<RenderSpritesInfo>, Requires<IBodyOrientationInfo>
+	{
+		[Desc("Sequence name to use")]
+		public readonly string Sequence = "production-overlay";
+
+		[Desc("Position relative to body")]
+		public readonly WVec Offset = WVec.Zero;
+
+		public object Create(ActorInitializer init) { return new WithProductionOverlay(init.self, this); }
+	}
+
+	public class WithProductionOverlay : INotifyDamageStateChanged, ITick, INotifyBuildComplete, INotifySold
+	{
+		Animation overlay;
+		ProductionQueue queue;
+		bool buildComplete;
+
+		bool IsProducing
+		{
+			get { return queue != null && queue.CurrentItem() != null && !queue.CurrentPaused; }
+		}
+
+		public WithProductionOverlay(Actor self, WithProductionOverlayInfo info)
+		{
+			var rs = self.Trait<RenderSprites>();
+			var body = self.Trait<IBodyOrientation>();
+
+			buildComplete = !self.HasTrait<Building>(); // always render instantly for units
+
+			overlay = new Animation(rs.GetImage(self));
+			overlay.PlayRepeating(info.Sequence);
+			rs.anims.Add("production_overlay_{0}".F(info.Sequence),
+				new AnimationWithOffset(overlay,
+					() => body.LocalToWorld(info.Offset.Rotate(body.QuantizeOrientation(self, self.Orientation))),
+					() => !IsProducing || !buildComplete));
+		}
+
+		public void Tick(Actor self)
+		{
+			// search for the queue here once so we don't rely on order of trait initialization
+			if (queue == null)
+			{
+				var production = self.TraitOrDefault<Production>();
+
+				var perBuildingQueues = self.TraitsImplementing<ProductionQueue>();
+				queue = perBuildingQueues.FirstOrDefault(q => production.Info.Produces.Contains(q.Info.Type));
+
+				if (queue == null)
+				{
+					var perPlayerQueues = self.Owner.PlayerActor.TraitsImplementing<ProductionQueue>();
+					queue = perPlayerQueues.FirstOrDefault(q => production.Info.Produces.Contains(q.Info.Type));
+				}
+
+				if (queue == null)
+					throw new InvalidOperationException("Can't find production queues.");
+			}
+		}
+
+		public void BuildingComplete(Actor self)
+		{
+			buildComplete = true;
+		}
+
+		public void Sold(Actor self) { }
+		public void Selling(Actor self)
+		{
+			buildComplete = false;
+		}
+
+		public void DamageStateChanged(Actor self, AttackInfo e)
+		{
+			overlay.ReplaceAnim(RenderSprites.NormalizeSequence(overlay, e.DamageState, overlay.CurrentSequence.Name));
+		}
+	}
+}