ChainAttacks.cs

 #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;
using System.Linq;
using OpenRA.Traits;

namespace OpenRA.Mods.RA
{
	// Order is important here!
	public enum ChainAttackModel
	{
		Multiplicative,
		Additive
	}

	[Desc("Actor can fire weapon at another ChainAttacks actor to increase the total damage output.")]
	public class ChainAttacksInfo : ITraitInfo, Requires<ArmamentInfo>
	{
		[Desc("Number of chained \"jumps\" our attack can perform.")]
		public readonly int MaximumChains = 1;

		[Desc("Actor receiving support classifications:")]
		public readonly string[] ReceiverTypes = { };

		[Desc("Actor sending support classification:")]
		public readonly string SenderType = null;

		[Desc("Defaults to primary Armament entry.")]
		public readonly string ArmamentName = "primary";

		[Desc("Range (in cells) that actor can scan for supporting ChainAttacks actors.")]
		public readonly WRange Range = WRange.FromCells(5);

		[Desc("Increase damage in a linear (Additive) or exponention (Multiplicative) fashion?")]
		public readonly ChainAttackModel DamageType = ChainAttackModel.Additive;

		[Desc("Amount of damage to add to total damage. Default is 0 which means \"add our weapon's default damage value.\"",
			"Only used if DamageType is Additive")]
		public readonly int LinearDamageAdded = 0;

		[Desc("Amount of damage to add to total damage. Default is 2.0 which doubles damage on each iteration.",
			"Only used if DamageType is Multiplicative")]
		public readonly float DamageMultiplier = 2.0f;

		public object Create(ActorInitializer init) { return new ChainAttacks(init.self, this); }
	}

	public class ChainAttacks : INotifyAttack, INotifyAppliedDamage
	{
		ChainAttacksInfo info;
		Armament weaponToUse;

		public ChainAttacks(Actor self, ChainAttacksInfo info)
		{
			this.info = info;
			weaponToUse = self.TraitsImplementing<Armament>()
				.FirstOrDefault(a => a.Info.Name == info.ArmamentName);
		}

		public void Attacking(Actor self, Target target, Armament a, Barrel barrel)
		{
			var supporters = self.World.FindActorsInCircle(self.CenterPosition, info.Range)
				.Where(s => s.SharesOwnerWith(self) && s.HasTrait<ChainAttacks>())
				.OrderBy(x => x.Trait<ChainAttacksInfo>().DamageType);

			var damageToAdd = 0;

			foreach (var supporter in supporters)
			{
				var cai = supporter.Info.Traits.Get<ChainAttacksInfo>();

				for (var i = 0; i < info.MaximumChains; i++)
					damageToAdd += RequestSupport(supporter, weaponToUse, cai.DamageType);

				Game.Debug("DamageToAdd: {0}.".F(damageToAdd));
			}

			// TODO: add `damageToAdd` to real damage output
		}

		int RequestSupport(Actor supporter, Armament arm, ChainAttackModel model)
		{
			var cai = supporter.Info.Traits.Get<ChainAttacksInfo>();
			if (!info.ReceiverTypes.Contains(cai.SenderType))
				return 0;

			var baseDamage = arm.Weapon.Warheads.First().Damage;

			return model == ChainAttackModel.Multiplicative ? (int)(baseDamage * info.DamageMultiplier) :
				(info.LinearDamageAdded == 0 ? baseDamage : info.LinearDamageAdded);
		}
	}
}