Auras

The aura system offers the following features:

• Automatically manages application and refreshing of buffs in a customisable manner
• Integrates with the buff system to allow easily customisable buffs to be applied
• Auras are bound to a specific buff to make it easier to work with

Usage

Creating an aura requires 2 classes to be created. The first thing we need is the buff to be applied. For this, you should use AuraBoundBuff, which is a small extension of BoundBuff that will help ensure that the auras will stack in a manner similar to default auras. Furthermore, it will ensure that the Stacks property is set to the number of aura bearers applying the buff.

using WCSharp.Buffs;
using static War3Api.Common;

public class MyBuff : AuraBoundBuff
{
	public MyBuff(unit caster, unit target) : base(caster, target)
	{
		EffectString = @"Abilities\Spells\Other\GeneralAuraTarget\GeneralAuraTarget.mdl";
		Bind(Constants.ABILITY_DEVOTION_AURA, Constants.BUFF_DEVOTION_AURA);
	}

	public override void OnApply()
	{
		BlzSetUnitArmor(Target, BlzGetUnitArmor(Target) + 5);
	}

	public override void OnExpire()
	{
		BlzSetUnitArmor(Target, BlzGetUnitArmor(Target) - 5);
	}
}

We don't need to set a duration here, this will be managed by the aura. For the aura itself, we'll inform C# that the aura should bind to MyBuff by extending it with Aura<MyBuff>. Then we can implement the abstract class, and create something like this:

public class MyAura : Aura<MyBuff>
{
	public MyAura(unit caster) : base(caster)
	{
		Radius = 800;
		EffectString = @"Abilities\Spells\Human\DevotionAura\DevotionAura.mdl";
		StackBehaviour = StackBehaviour.Stack;
	}

	// Use this to create new instances of MyBuff and perform additional initialisation if necessary
	protected override MyBuff CreateAuraBuff(unit unit)
	{
		return new MyBuff(Caster, unit);
	}

	// Use this to filter on units that should be buffed by this aura
	protected override bool UnitFilter(unit unit)
	{
		return IsUnitAlly(unit, CastingPlayer);
	}
}

And that's it! We now have our own Devotion Aura, including having it show a buff on the unit. This particular implementation won't show a "+5" on the unit stats, but you can easily achieve this by increasing the armour via a different method than BlzSetUnitArmor, such as giving the unit an item ability that increases armour.

Finally, to add this aura to a unit, simply create a new instance and add it to the system:

var unit = GetTriggerUnit();
var aura = new MyAura(unit);
AuraSystem.Add(aura);

Properties

Name	Description
Active	Inherited from IPeriodicDisposableAction. Set to false to disable and dispose.
Caster	The owner of the aura.
CastingPlayer	The player who owns the aura. This is set on creation, if you want it to automatically update, use AuraSystem.RegisterForOwnershipChanges.
Radius	The range within which units must be for the aura to be applied to them.
Duration	The duration in seconds of buffs applied by this aura. Defaults to 3.1. Unless you're making a pulsing aura, you will want the Duration to be greater than the SearchInterval.
SearchIntervalLeft	How long in seconds until this aura will next be applied to valid units in range.
SearchInterval	How long in seconds between applications of this aura. Defaults to 1.0.
StackBehaviour	The stack behaviour of buffs applied by this aura. Note that even with StackBehaviour.None, auras will still only stack once per aura instance.
EffectString	The path of the effect to use. Leave empty for no effect. If changed while the aura is already active, will destroy and recreate the effect.
EffectAttachmentPoint	The attachment point for the effect. If changed while the aura is already active, will destroy and recreate the effect at the desired attachment point. Defaults to origin.
EffectScale	The effect scale for the effect. If changed while the aura is already active, automatically modifies the effect.
Effect	The effect used by the aura. Creation of the effect should be done by setting EffectString, not by setting this property.
ActiveBuffsByUnit	A dictionary mapping units to active buffs.