RefactoringCode&Prefab — UnityGameDebut

Let’s Refactoring The Code — Episode #06

Published in

KidsTronics

4 min readMar 4, 2018

Hi, you there! Here is the previous code. Our solitary enemy is moving to the left and back … let’s add another enemy to the scene. Let’s go straight to the code refactoring:

Step #01 — Let’s pick Soldier.cs up to where we left off:

void Start () {
 
    // Grab the enemy’s ref.      mEnemy = transform.GetChild(0).gameObject;    // Get enemy position & use trig function
    // to move it to the left during 1sec
 
    enemyPos = mEnemy.transform.position; 
    enemyPos.z += Mathf.Cos(0.1f);     iTween.MoveTo(mEnemy, enemyPos, 1.0f); }

Refactoring Soldier.cs code by transport the last 3 lines to a new method and name it says MoveLeftwards() — use the lamp bulb icon; type:

private void MoveLeftwards()
    {    //TODO: Shooting logics goes here
       
    //Get enemy position and use trig function to move it Vector3  
    enemyPos = mEnemy.transform.position; 
    enemyPos.z += Mathf.Cos(0.1f);
    
    iTween.MoveTo(mEnemy, enemyPos, 1.0f); 
}

Step #02 —Copy & paste and make another method in Soldier.cs named MoveRightwards(); invert the angle; save everything;

private void MoveRightwards()
    {
        //TODO: stop Shootting at us log goes here!
     
        //Move upwards
        Vector3 enemyPos = mEnemy.transform.position;
        enemyPos.z -= Mathf.Cos(-0.1f);       iTween.MoveTo(mEnemy, enemyPos, LeftTime);    }

The moment the enemy is in the left position he will shoot at us:/ when he’s in the right position he must go back to the idle status…but this is for further down the road (TODO list);

Step #03 —In Soldier.cs, Use Invoke() on Start() to call the MoveRightwards() after 3s; see:

void Start (){   MoveLeftwards();   //return to the right position and stayd there        
   Invoke("MoveRightwards", 3.0f);}

Step #04 — Now we need 3 variables in Soldier.cs to control the time the enemy is in the left (LeftTime), shooting at us (ShootTime) and in the right (right time) positions:

public float LeftTime =  2.0f;
public float ShootTime = 1.0f;
public float RightTime = 3.0f;

Substitute all the magic numbers in Soldier.cs…

void Awake(){    (...)
    Invoke("MoveRightwards", ShootTime);}private void MoveLeftwards(){    (...)
    iTween.MoveTo(mEnemy, enemyPos, LeftTime);}private void MoveRightwards(){
    (...)
    iTween.MoveTo(mEnemy, enemyPos, RightTime);}

Step #05 — Let’s add Soldier.Activate() so that the method that controls the enemy status is not in the Start(), and let’s make it callable (public) from other objects :

public void Activate(){   MoveLeftwards();   //return to the right position and stayed there        
   Invoke("MoveRightwards", RightTime);}

The enemy moves to the left position and returns back to the right and remains there. Meanwhile, he must shoot at us, right? For this, we need a controller: EnemyController.cs responsible for the soldier's behavior control. Here’s the concept:

Note that each soldier has it’s own behavior, but **EnemyController** controls them all together.

Step #06–Create an 1) Empty gameObject, 2) rename it to EnemyController, 3) right mouse click, Create > C# Script, name it EnemyController.cs, and 4) drag n’ drop this to gameObject just created;

Step #07 —Using Prefabs: 1) Create a folder Assets >Prefabs, then create a prefab by selecting 2) Assets > Create Prefab inside this folder, then 3) dragging Soldier gameObject onto the empty prefab asset that appears, and 4) finally rename it to Soldier; Simply dragging the prefab asset from the project view to the scene view will then create instances of the prefab. Objects created as prefab instances will be shown in the hierarchy view in blue text. (Normal objects are shown in black text);

Step #08 — Now 1) add prefab Soldier to the scene and positioning it at the third tower; 2) Rewrite its name, Soldier(1) and Soldier(2);

Step #09— Go to Assets > Scripts > EnemyController.cs and add an array of Soldier named Enemies (save it) :

public Soldier[] Enemies;

Step #10 — Return to Unity and 1) Select EnemyController on Explorer, then you’ll see these property Enemies — since it’s public; 2) type size=2 and them 3) Drag n’ drop the objects Soldier(1) and Soldier(2) to the slots created;