View source for Creating a Behavior

Behaviors are classes that control a [[Unit]]. For example, health items have the Pickup behavior. This pickup behavior responds to the <code>Collide</code> function, so that it can perform an [[Effect]] when a [[Player]] touches the item.

__TOC__

==Minimal behavior==

The most basic behavior is one that does nothing and simply stores the [[UnitPtr]]:

<pre class="prettyprint">
class MyBehavior
{
  UnitPtr m_unit;

  MyBehavior(UnitPtr unit, SValue& params)
  {
    m_unit = unit;
  }
}
</pre>

==Parameters==

You can define parameters in your [[Unit file]], and then fetch them in your Behavior script. Take for example the following integer in the Behavior XML:

<pre class="prettyprint">
<behavior class="MyBehavior">
  <int name="move-time">1000</int>
</behavior>
</pre>

Then, to get the value of <code>move-time</code> in your script, you can do the following:

<pre class="prettyprint">
int m_moveTime;

MyBehavior(UnitPtr unit, SValue& params)
{
  m_unit = unit;
  m_moveTime = GetParamInt(unit, params, "move-time");
}
</pre>

To make the value optional instead of required, add the 4th optional argument <code>false</code>, followed by an optional default value. For example, if you would like <code>move-time</code> in the above example to be optional and default to 1000, you would do this:

<pre class="prettyprint">
m_moveTime = GetParamInt(unit, params, "move-time", false, 1000);
</pre>

==Functions==
Further, you can implement any function you'd like from the below list in your class, and they will be called as events.

<pre>
void Update(int dt)
void QueuedPathfind(array<vec2>@ path)
void QueuedFetchActors(array<UnitPtr>@ actors)
void Collide(UnitPtr unit, vec2 pos, vec2 normal)
void Collide(UnitPtr unit, vec2 pos, vec2 normal, Fixture@ fxSelf, Fixture@ fxOther)
void EndCollision(UnitPtr unit)
void EndCollision(UnitPtr unit, Fixture@ fxSelf, Fixture@ fxOther)
void Destroyed()
vec4 GetOverlayColor()
SValue@ Save()
void Load(SValue@ save)
void PostLoad(SValue@ save)
</pre>

[[Category:Tutorials]]