Add GrantPrerequisiteChargeDrainPower and DrainPrerequisitePowerOnDamage.

These traits implement the Firestorm defense charge/drain logic.

OpenRA.Mods.Cnc/Traits/DrainPrerequisitePowerOnDamage.cs

@@ -0,0 +1,68 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2019 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, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Cnc.Traits
+{
+	[Desc("Converts damage to a charge level of a GrantPrerequisiteChargeDrainPower.")]
+	public class DrainPrerequisitePowerOnDamageInfo : ConditionalTraitInfo
+	{
+		[Desc("The OrderName of the GrantPrerequisiteChargeDrainPower to drain.")]
+		public readonly string OrderName = "GrantPrerequisiteChargeDrainPowerInfoOrder";
+
+		[Desc("Damage is multiplied by this number when converting damage to drain ticks.")]
+		public readonly int DamageMultiplier = 1;
+
+		[Desc("Damage is divided by this number when converting damage to drain ticks.")]
+		public readonly int DamageDivisor = 600;
+
+		public override object Create(ActorInitializer init) { return new DrainPrerequisitePowerOnDamage(init.Self, this); }
+	}
+
+	public class DrainPrerequisitePowerOnDamage : ConditionalTrait<DrainPrerequisitePowerOnDamageInfo>, INotifyOwnerChanged, IDamageModifier
+	{
+		SupportPowerManager spm;
+
+		public DrainPrerequisitePowerOnDamage(Actor self, DrainPrerequisitePowerOnDamageInfo info)
+			: base(info) { }
+
+		protected override void Created(Actor self)
+		{
+			base.Created(self);
+			spm = self.Owner.PlayerActor.Trait<SupportPowerManager>();
+		}
+
+		void INotifyOwnerChanged.OnOwnerChanged(Actor self, Player oldOwner, Player newOwner)
+		{
+			spm = newOwner.PlayerActor.Trait<SupportPowerManager>();
+		}
+
+		int IDamageModifier.GetDamageModifier(Actor self, Damage damage)
+		{
+			if (!IsTraitDisabled && damage != null)
+			{
+				var damageSubTicks = (int)(damage.Value * 100L * Info.DamageMultiplier / Info.DamageDivisor);
+
+				SupportPowerInstance spi;
+				if (spm.Powers.TryGetValue(Info.OrderName, out spi))
+				{
+					var dspi = spi as GrantPrerequisiteChargeDrainPower.DischargeableSupportPowerInstance;
+					if (dspi != null)
+						dspi.Discharge(damageSubTicks);
+				}
+			}
+
+			return 100;
+		}
+	}
+}

OpenRA.Mods.Cnc/Traits/SupportPowers/GrantPrerequisiteChargeDrainPower.cs

@@ -0,0 +1,211 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2019 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, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Collections.Generic;
+using System.Linq;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Cnc.Traits
+{
+	[Desc("Grants a prerequisite while discharging at a configurable rate.")]
+	public class GrantPrerequisiteChargeDrainPowerInfo : SupportPowerInfo, ITechTreePrerequisiteInfo
+	{
+		[Desc("Rate at which the power discharges compared to charging")]
+		public readonly int DischargeModifier = 300;
+
+		[FieldLoader.Require]
+		[Desc("The prerequisite type that this provides.")]
+		public readonly string Prerequisite = null;
+
+		[Translate]
+		[Desc("Label to display over the support power icon and in its tooltip while the power is active.")]
+		public readonly string ActiveText = "ACTIVE";
+
+		[Translate]
+		[Desc("Label to display over the support power icon and in its tooltip while the power is available but not active.")]
+		public readonly string AvailableText = "READY";
+
+		IEnumerable<string> ITechTreePrerequisiteInfo.Prerequisites(ActorInfo info)
+		{
+			yield return Prerequisite;
+		}
+
+		public override object Create(ActorInitializer init) { return new GrantPrerequisiteChargeDrainPower(init.Self, this); }
+	}
+
+	public class GrantPrerequisiteChargeDrainPower : SupportPower, ITechTreePrerequisite, INotifyOwnerChanged
+	{
+		readonly GrantPrerequisiteChargeDrainPowerInfo info;
+		TechTree techTree;
+		bool active;
+
+		public GrantPrerequisiteChargeDrainPower(Actor self, GrantPrerequisiteChargeDrainPowerInfo info)
+			: base(self, info)
+		{
+			this.info = info;
+		}
+
+		protected override void Created(Actor self)
+		{
+			// Special case handling is required for the Player actor.
+			// Created is called before Player.PlayerActor is assigned,
+			// so we must query other player traits from self, knowing that
+			// it refers to the same actor as self.Owner.PlayerActor
+			var playerActor = self.Info.Name == "player" ? self : self.Owner.PlayerActor;
+
+			techTree = playerActor.Trait<TechTree>();
+
+			base.Created(self);
+		}
+
+		void INotifyOwnerChanged.OnOwnerChanged(Actor self, Player oldOwner, Player newOwner)
+		{
+			techTree = newOwner.PlayerActor.Trait<TechTree>();
+			active = false;
+		}
+
+		public override SupportPowerInstance CreateInstance(string key, SupportPowerManager manager)
+		{
+			return new DischargeableSupportPowerInstance(key, info, manager);
+		}
+
+		public void Activate(Actor self, SupportPowerInstance instance)
+		{
+			active = true;
+			techTree.ActorChanged(self);
+		}
+
+		public void Deactivate(Actor self, SupportPowerInstance instance)
+		{
+			active = false;
+			techTree.ActorChanged(self);
+		}
+
+		IEnumerable<string> ITechTreePrerequisite.ProvidesPrerequisites
+		{
+			get
+			{
+				if (!active)
+					yield break;
+
+				yield return info.Prerequisite;
+			}
+		}
+
+		public class DischargeableSupportPowerInstance : SupportPowerInstance
+		{
+			// Whether the power is available to activate (even if not fully charged)
+			bool available;
+
+			// Whether the power is active right now
+			// Note that this is fundamentally different to SupportPowerInstance.Active
+			// which has a much closer meaning to available above.
+			bool active;
+
+			// Additional discharge rate accrued from damage
+			int additionalDischargeSubTicks = 0;
+
+			public DischargeableSupportPowerInstance(string key, GrantPrerequisiteChargeDrainPowerInfo info, SupportPowerManager manager)
+				: base(key, info, manager) { }
+
+			void Deactivate()
+			{
+				active = false;
+				notifiedCharging = false;
+
+				// Fully depleting the charge disables the power until it is again fully charged
+				if (!Active || remainingSubTicks >= TotalTicks * 100)
+					available = false;
+
+				foreach (var p in Instances)
+					((GrantPrerequisiteChargeDrainPower)p).Deactivate(p.Self, this);
+			}
+
+			public override void Tick()
+			{
+				var orig = remainingSubTicks;
+				base.Tick();
+
+				if (Ready)
+					available = true;
+
+				if (active && !Active)
+					Deactivate();
+
+				if (active)
+				{
+					remainingSubTicks = orig + ((GrantPrerequisiteChargeDrainPowerInfo)Info).DischargeModifier + additionalDischargeSubTicks;
+					additionalDischargeSubTicks = 0;
+
+					if (remainingSubTicks > TotalTicks * 100)
+					{
+						remainingSubTicks = TotalTicks * 100;
+						Deactivate();
+					}
+				}
+			}
+
+			public void Discharge(int subTicks)
+			{
+				additionalDischargeSubTicks += subTicks;
+			}
+
+			public override void Target()
+			{
+				if (available && Active)
+					Manager.Self.World.IssueOrder(new Order(Key, Manager.Self, false) { ExtraData = active ? 0U : 1U });
+			}
+
+			public override void Activate(Order order)
+			{
+				if (active && order.ExtraData == 0)
+				{
+					Deactivate();
+					return;
+				}
+
+				if (!available || order.ExtraData != 1)
+					return;
+
+				var power = Instances.FirstOrDefault(i => !i.IsTraitPaused);
+				if (power == null)
+					return;
+
+				active = true;
+
+				// Only play the activation sound once!
+				power.PlayLaunchSounds();
+
+				foreach (var p in Instances)
+					((GrantPrerequisiteChargeDrainPower)p).Activate(p.Self, this);
+			}
+
+			public override string IconOverlayTextOverride()
+			{
+				var info = Info as GrantPrerequisiteChargeDrainPowerInfo;
+				if (info == null || !Active)
+					return null;
+
+				return active ? info.ActiveText : available ? info.AvailableText : null;
+			}
+
+			public override string TooltipTimeTextOverride()
+			{
+				var info = Info as GrantPrerequisiteChargeDrainPowerInfo;
+				if (info == null || !Active)
+					return null;
+
+				return active ? info.ActiveText : available ? info.AvailableText : null;
+			}
+		}
+	}
+}

OpenRA.Mods.Common/Traits/SupportPowers/SupportPowerManager.cs

@@ -159,7 +159,7 @@ namespace OpenRA.Mods.Common.Traits
 		bool instancesEnabled;
 		bool prereqsAvailable = true;
 		bool oneShotFired;
-		bool notifiedCharging;
+		protected bool notifiedCharging;
 		bool notifiedReady;
 
 		public SupportPowerInstance(string key, SupportPowerInfo info, SupportPowerManager manager)