Add AttackSounds trait

This trait plays sounds when preparing to attack or attacking.

OpenRA.Mods.Common/OpenRA.Mods.Common.csproj

@@ -481,6 +481,7 @@
     <Compile Include="Traits\Sound\CaptureNotification.cs" />
     <Compile Include="Traits\Sound\DeathSounds.cs" />
     <Compile Include="Traits\Sound\SoundOnDamageTransition.cs" />
+    <Compile Include="Traits\Sound\AttackSounds.cs" />
     <Compile Include="Traits\SupplyTruck.cs" />
     <Compile Include="Traits\SupportPowers\AirstrikePower.cs" />
     <Compile Include="Traits\SupportPowers\GrantUpgradePower.cs" />

OpenRA.Mods.Common/Traits/Sound/AttackSounds.cs

@@ -0,0 +1,80 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2016 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.Linq;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Traits.Sound
+{
+	[Desc("Played when preparing for an attack or attacking.")]
+	public class AttackSoundsInfo : UpgradableTraitInfo
+	{
+		[Desc("Play a randomly selected sound from this list when preparing for an attack or attacking.")]
+		public readonly string[] Sounds = { };
+
+		[Desc("Delay in ticks before sound starts, either relative to attack preparation or attack.")]
+		public readonly int Delay = 0;
+
+		[Desc("Should the sound be delayed relative to preparation or actual attack?")]
+		public readonly AttackDelayType DelayRelativeTo = AttackDelayType.Preparation;
+
+		public override object Create(ActorInitializer init) { return new AttackSounds(init, this); }
+	}
+
+	public class AttackSounds : UpgradableTrait<AttackSoundsInfo>, INotifyAttack, ITick
+	{
+		readonly AttackSoundsInfo info;
+		int tick;
+
+		public AttackSounds(ActorInitializer init, AttackSoundsInfo info)
+			: base(info)
+		{
+			this.info = info;
+		}
+
+		void PlaySound(Actor self)
+		{
+			if (info.Sounds.Any())
+				Game.Sound.Play(info.Sounds.Random(self.World.SharedRandom), self.CenterPosition);
+		}
+
+		void INotifyAttack.Attacking(Actor self, Target target, Armament a, Barrel barrel)
+		{
+			if (info.DelayRelativeTo == AttackDelayType.Attack)
+			{
+				if (info.Delay > 0)
+					tick = info.Delay;
+				else
+					PlaySound(self);
+			}
+		}
+
+		void INotifyAttack.PreparingAttack(Actor self, Target target, Armament a, Barrel barrel)
+		{
+			if (info.DelayRelativeTo == AttackDelayType.Preparation)
+			{
+				if (info.Delay > 0)
+					tick = info.Delay;
+				else
+					PlaySound(self);
+			}
+		}
+
+		void ITick.Tick(Actor self)
+		{
+			if (IsTraitDisabled)
+				return;
+
+			if (info.Delay > 0 && --tick == 0)
+				PlaySound(self);
+		}
+	}
+}