Game Development Reference
In-Depth Information
Awake versus Start
The
GameManager
class uses the
Awake
function, as opposed to
Start
, in code sample 3-12. The difference between
Start
and
Awake
is as follows:
Awake
is always called before
Start
.
Awake
is always called at object creation.
Start
is called on the first
frame in which the
GameObject
becomes active. If a
GameObject
starts the scene deactivated, then
Start
will not be called until the
object is activated. For objects that are activated by default,
Start
is
called at the beginning of the scene, after the
Awake
event.
If you need to cache component references into local variables of a
class, such as the Transform component in
ThisTransform
, then
use the
Awake
event rather than
Start
. During the
Start
event,
the assumption should be that all local references to objects are
already valid.
The great benefit of having a global, static
Instance
property for
GameManager
is that it becomes instantly and directly accessible to any other script file, without
the need for any local variables or object references. This means every class has
instant access to all
GameManager
properties and can call upon high-order game
functionality. For example, to set the game score variable on the
GameManager
from a different class, the following code sample 3-15 can be used:
using UnityEngine;
using System.Collections;
//-------------------------------------------
public class ScoreSetter : MonoBehaviour
{
//-------------------------------------------
// Use this for initialization
void Start ()
{
//Set score on GameManager
GameManager.Instance.HighScore = 100;
}
//-------------------------------------------
}
//-------------------------------------------
More information on singleton objects can be found online at
