Move warheads into mod code.

OpenRA.Mods.RA/Warheads/SpreadDamageWarhead.cs

@@ -0,0 +1,75 @@
+#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.Effects;
+using OpenRA.GameRules;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA
+{
+	public class SpreadDamageWarhead : DamageWarhead
+	{
+		[Desc("For Normal DamageModel: Distance from the explosion center at which damage is 1/2.")]
+		public readonly WRange Spread = new WRange(43);
+
+		public override void DoImpact(WPos pos, Actor firedBy, float firepowerModifier)
+		{
+			var world = firedBy.World;
+			var maxSpread = new WRange((int)(Spread.Range * (float)Math.Log(Math.Abs(Damage), 2)));
+			var hitActors = world.FindActorsInCircle(pos, maxSpread);
+
+			foreach (var victim in hitActors)
+				if (IsValidAgainst(victim, firedBy))
+				{
+					var damage = (int)GetDamageToInflict(pos, victim, firedBy, firepowerModifier);
+					victim.InflictDamage(firedBy, damage, this);
+				}
+		}
+
+		public override void DoImpact(Actor victim, Actor firedBy, float firepowerModifier)
+		{
+			if (IsValidAgainst(victim, firedBy))
+			{
+				var damage = GetDamageToInflict(victim.CenterPosition, victim, firedBy, firepowerModifier);
+				victim.InflictDamage(firedBy, damage, this);
+			}
+		}
+
+		public int GetDamageToInflict(WPos pos, Actor target, Actor firedBy, float modifier)
+		{
+			var healthInfo = target.Info.Traits.GetOrDefault<HealthInfo>();
+			if (healthInfo == null)
+				return 0;
+
+			var distance = Math.Max(0, (target.CenterPosition - pos).Length - healthInfo.Radius.Range);
+			var falloff = (float)GetDamageFalloff(distance * 1f / Spread.Range);
+			var rawDamage = (float)(falloff * Damage);
+
+			return (int)(rawDamage * modifier * EffectivenessAgainst(target.Info));
+		}
+
+		static readonly float[] falloff =
+		{
+			1f, 0.3678795f, 0.1353353f, 0.04978707f,
+			0.01831564f, 0.006737947f, 0.002478752f, 0.000911882f
+		};
+
+		static float GetDamageFalloff(float x)
+		{
+			var u = (int)x;
+			if (u >= falloff.Length - 1) return 0;
+			var t = x - u;
+			return (falloff[u] * (1 - t)) + (falloff[u + 1] * t);
+		}
+	}
+}