WEBVTT

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Game Advanced
Beta Type Version

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GCC Academy

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Hello

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I am Lee Youngho, in charge of the shooting game development lecture

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In this chapter, we will learn the Beta Type version

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First, we will learn how to create a manager using the Singleton design pattern

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We will understand design patterns and learn how to create

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and use the Singleton pattern for score management

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Next, we will learn about memory management using objectPool

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We will implement objectPooling

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using array and list data structures

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Creating a Manager Using the Singleton Design Pattern

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Let's learn how to create a manager

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using the Singleton pattern

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The pattern you see here refers to a design pattern

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which is essentially a way of structuring or designing the system

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Singleton is like this

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Singleton literally means something singular

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When using these single instances

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C# provides grammatical elements in the pattern

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A key grammatical element used in the Singleton pattern

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is static

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Like this

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Let's draw a circle

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We call it a class or an instance

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Anyway, these are objects

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Right? these are objects

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Object A

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Object B

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Each of them has its own member variables

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properties and features like this

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properties and features are going to be here like this

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The variables inside this function

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are called local variables

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The variables that are inside the class but outside the functions are called member variables

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and from the class's perspective, they are considered global

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From its perspective, these are considered global

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Why? Because it can access them as well

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But this one,  called member variables

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Let's say each object is like a school

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Jane is here

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John is here

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For each object

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In school, when they want to share information with everyone

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what do they use?

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They utilize a white board

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white board right?

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On the board, detention

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John

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we can write like this

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then who would've written this?

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Of course, someone must have written this

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for contents to be registered on the board

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The area where everyone has access to

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is what we call the Static area

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So this is a static area

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In this area

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we could have a detention list

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like this

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the important part is actually, who wrote this

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Someone must've written it to be there

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When the teacher comes in and asks

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who wrote this?

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So, they place the reference

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Who wrote this? Jane wrote it

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Right here, we specify Jane wrote this

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Attach Jane as a reference

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Jane. reference, like this

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Jane is the name of the class

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We can use the class name this here

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But then she writes again

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under Detention list, John, Jane wrote the same thing again

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If they wrote the same thing over and over

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the teacher can

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be angry with the kids

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So, in here

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Just like I mentioned

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Can there be two variables of the same name?

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There shouldn't be

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Since this is a storage, data area

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you can use static to register data here

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with static attached

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and utilize it

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of course we can add functions

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With one reference

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We can only register one variable

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This is what static area is all about

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This design method is

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called the Singleton pattern

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We can use this method

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to make our ScoreManager

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There are several ways of making

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different singleton patterns

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Here, we will create and use it

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in a simplified form

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But the content is the same

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Open ScoreManager.cs

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Open it from the visual studio

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I will go here

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GetScore

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below that

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and right above Start function

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let me declare

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Here, we will create a Singleton object

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public static here

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attach static over here

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grammatically

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and then, with whose name?

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with this ScoreManager's name

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it can be registered as a reference

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for the variable that comes after

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So, we first write the data type after this

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We will register ScoreManager here

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since the name is a variable

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Typically, Singleton objects are written in uppercase

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Instance like this

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Let's leave it without any value

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Then, a singleton object

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gets registered right here

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With the name of Instance

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The data type will be registered as ScoreManager

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How can we make it?

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ScoreManager.Instance

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Like this

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then we don't have when

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There's no value to it

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when are we going to specify the value here?

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What kind of value goes in there?

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When you press the play button

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the ScoreManager object will be

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loaded into memory

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meaning it will be created

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and it is instance

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When it's being created

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we can have the value in here

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then we can use Start function

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it can be good if we do that

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Start and similar ones

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are life cycle function right?

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Life cycle functions

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go through a life of getting created and removed

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These also have the point of view

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First, we have Jane here

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the number one

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this one is created first

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and then the number two is created next

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when that happens, number two wants to know about number one

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So, it uses number one dot, name dot and so on

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accessing will face no problems

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but what's the problem? this could happen

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If it's trying to access the second instance

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before it has been created

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it would cause a problem because the instance doesn't exist yet

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So, would it be a problem or no?

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Of course it will be, because it doesn't exist yet

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It just doesn't exist

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So, it is required to be assumed

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that they must exist together

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For that

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Which life cycle function should we use?

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There's a function called Awake

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This Awake function, when we press play

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we have in our world

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the ones that are registered

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ones that are already added into the hierarchy

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In those cases

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the Awake function is called first

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That's why this one is already created

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it's not born yet, only been conceived

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Then, those objects will call

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all of their Awake functions first

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and handle their initialization

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after all the Awake functions

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of the objects are called and process is complete

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Then, the OnEnabled function

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an event function is called next

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After this one

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Only after that, the Start function

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will be called for all the objects collectively

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In other words, if we set the

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ScoreManager's Instance value

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in the Awake function, the value will already be assigned

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so there won't be any problems

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So, we will create an Awake function

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and set the value there

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Right above Start function

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I will make an Awake function like this

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In here, when the Instance has to no

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If, Instance has no value, null

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What are we going to do then?

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By using this, you are referring

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to the instance of the object itself

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The Instance object refers to the ScoreManager object

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This Instance Object

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Itself wants to be in there

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So, in the world, who is it?

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It is the ScoreManager object itself

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being assigned to the Instance variable

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How do we access it?

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Use ScoreManager

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Then how do we want

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others to access me?

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When you access it here

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we are referring

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to myself by using Jane.me

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We can access and use the Instance object here

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as much as we want

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Now, let's take a quick look at how

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this makes things much more convenient

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Go into Enemy.cs

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To get the value for this one

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Find the GameObject first

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There was the inconvenience of having

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to retrieve the ScoreManager component

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Now, this part is no longer necessary

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Need no more

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Instead of using sm, you can directly use ScoreManager.Instance

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to access the ScoreManager instance

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Just like so

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Because it's directly the ScoreManager instance

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we can directly assign it here like this

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By doing this, we can access and use it conveniently

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without having to find other objects

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This is the advantage of utilizing singleton pattern

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Save it and go back to Unity

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To press play button

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the normal increase of the current score when running the game has been confirmed

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You can see that the current score is

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increasing correctly

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But if we only use it this way

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it can feel a bit inconvenient

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Why?

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It’s quite difficult to interpret here, right?

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Let's say you guys just came back after a few days of sleep

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If you looked at this code after about ten days

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you'd have to deal with the issue of interpreting it

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What is this all about?

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It means that the readability is low

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To improve the readability of this part, we can make adjustments

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Let's try using the Get Set properties

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provided by the C# language to improve this

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Let's move to ScoreManager.cs

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By using Get/Set Property form C#

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Let's create the ones

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 that are under GetScore

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and SetScore

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Get set Property's grammar is very simple

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Look at it this way

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Do you know what Sphinx is?

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It has human head

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But what body does it have?

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It has a body of a lion, some kind of man beast

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It seems like the Sphinx might be strange, but it's that kind of feeling

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What is this?

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Two different species are combined together

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In this way, different types of forms have been combined

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So, you can think of the Get/Set properties

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in a similar way

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The head part is the variable being used, so it functions like a variable

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The head part is the variable

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and the body part

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the body part is the function

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This is how the Get/Set properties are used

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As we use ScoreManager

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Let's look into it in details

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Shall we first create a SetProperty

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to make the Get/Set properties below?

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Let's create GetProperty and SetProperty like this

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We will add public to allow external access

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set the type to int, and name it Score

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You will access it using the name Score like this

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How is it? Up to this point, it just looks like a variable

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but now the body part has been added

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This is the characteristic of Get/Set properties

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By adding Get/Set properties here

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we can create a function like GetScore

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Just like creating a Get function

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The role it does

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We will take the role from here and place it here

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Then, it will be able to perform exactly the same role as the GetScore function

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The content is implemented like a function

282
00:12:22.419 --> 00:12:24.987
Now, let's add the SetProperty

283
00:12:26.700 --> 00:12:30.859
The Set works the same way as SetScore

284
00:12:30.859 --> 00:12:34.900
So, you can take the part from SetScore

285
00:12:34.900 --> 00:12:36.059
select everything

286
00:12:36.059 --> 00:12:38.219
Let's cut it and place it elsewhere

287
00:12:38.219 --> 00:12:44.219
Ctrl and x and place it inside the Set function

288
00:12:44.219 --> 00:12:48.539
We have transformed the function into a Get Set property

289
00:12:48.539 --> 00:12:52.380
Why? This is done for usability and readability

290
00:12:52.380 --> 00:12:55.260
So, how do you use it?

291
00:12:55.260 --> 00:12:57.500
You can use it like a variable

292
00:12:57.500 --> 00:13:00.580
If you use it like a variable, you want to get the value

293
00:13:00.580 --> 00:13:03.059
Usually, when getting the value, how do we do it?

294
00:13:03.059 --> 00:13:08.859
In the form on the right, we have the assignment operator

295
00:13:08.859 --> 00:13:12.299
When you have int a, let's say we assign 10 to it

296
00:13:12.299 --> 00:13:14.659
Then call this assignment operator

297
00:13:14.659 --> 00:13:16.340
Right? assignment operator

298
00:13:16.340 --> 00:13:19.340
Then what do we call this part on the right?

299
00:13:19.340 --> 00:13:21.558
Usually we refer to it as R value, the value on the right side of the equation

300
00:13:21.558 --> 00:13:23.179
So, when we have this

301
00:13:23.179 --> 00:13:26.580
We call Get right away

302
00:13:26.580 --> 00:13:29.859
Get, right?

303
00:13:29.859 --> 00:13:31.259
How about on the left side?

304
00:13:31.259 --> 00:13:36.580
We are inserting the value, making it Set

305
00:13:36.580 --> 00:13:38.619
Did you understand? L value for this one

306
00:13:38.619 --> 00:13:40.580
Sending the value on the right side to the left

307
00:13:40.580 --> 00:13:44.380
Get for this side, and Set for the other side

308
00:13:44.380 --> 00:13:46.859
Did you understand?

309
00:13:46.859 --> 00:13:48.500
When you want to get a certain value

310
00:13:48.500 --> 00:13:50.219
For this value, use Get

311
00:13:50.219 --> 00:13:52.739
and for the other, use Set

312
00:13:52.739 --> 00:13:54.689
And for this one here

313
00:13:54.689 --> 00:13:56.780
use it like it's a variable

314
00:13:56.780 --> 00:13:59.739
Let's take a look at how to use it

315
00:13:59.739 --> 00:14:03.580
Since the Get and Set functions

316
00:14:03.580 --> 00:14:05.419
will be replaced with Get/Set properties

317
00:14:05.419 --> 00:14:10.059
we will go ahead and delete them

318
00:14:10.059 --> 00:14:11.780
Now, we will use Score

319
00:14:11.780 --> 00:14:15.700
and move on to Enemy.cs

320
00:14:15.700 --> 00:14:18.659
Things are made complex like this, right?

321
00:14:18.659 --> 00:14:20.020
How can we handle this part?

322
00:14:20.020 --> 00:14:21.859
We can make it a single line like this

323
00:14:21.859 --> 00:14:25.299
In ScoreManager, the Instance part remains the same

324
00:14:25.299 --> 00:14:28.179
Getting the Singleton object is the same

325
00:14:28.179 --> 00:14:30.179
But here, which do we use?

326
00:14:30.179 --> 00:14:33.539
the Score variable is a Get/Set property

327
00:14:33.539 --> 00:14:37.059
It looks like a variable, but its body is a function

328
00:14:37.059 --> 00:14:40.380
We want to increase the value here

329
00:14:40.380 --> 00:14:41.500
like this

330
00:14:41.500 --> 00:14:43.900
Then we are increasing the value

331
00:14:43.900 --> 00:14:45.739
How are we supposed to use this?

332
00:14:45.739 --> 00:14:47.700
Actually it is set up like this

333
00:14:47.700 --> 00:14:53.099
this code essentially retrieves the current value of Score

334
00:14:53.099 --> 00:14:54.979
and then adds 1 to it

335
00:14:54.979 --> 00:15:01.380
You can do this to increase by 1

336
00:15:01.380 --> 00:15:03.830
Originally, this is implemented in a way

337
00:15:03.830 --> 00:15:05.299
that allows it to be shortened

338
00:15:05.299 --> 00:15:08.340
So, as you can see, here it is getting the value

339
00:15:08.340 --> 00:15:09.619
which is the Get

340
00:15:09.619 --> 00:15:13.140
Then, when we add the two values and put the result back here

341
00:15:13.140 --> 00:15:15.140
it becomes Set

342
00:15:15.140 --> 00:15:16.260
Did you understand?

343
00:15:16.260 --> 00:15:21.780
How is the readability between the one above

344
00:15:21.780 --> 00:15:24.020
and the one below, given how simple it is?

345
00:15:24.020 --> 00:15:25.979
At once, you can know that

346
00:15:25.979 --> 00:15:26.700
this one increases the score

347
00:15:26.700 --> 00:15:28.780
This one is somewhat complicated

348
00:15:28.780 --> 00:15:30.630
So, with this part

349
00:15:30.630 --> 00:15:33.940
we will upgrade it

350
00:15:33.940 --> 00:15:36.539
Save it

351
00:15:36.539 --> 00:15:38.700
When we save it inside here

352
00:15:38.700 --> 00:15:40.619
and actually have the screen updated

353
00:15:40.619 --> 00:15:41.700
in details

354
00:15:41.700 --> 00:15:46.099
check every bit of this saves properly

355
00:15:46.099 --> 00:15:47.114
Let's play it now

356
00:16:06.419 --> 00:16:08.940
Right now, I see the current score and the high score are being updated

357
00:16:08.940 --> 00:16:10.609
I will turn it off and then turn it back on

358
00:16:12.619 --> 00:16:16.219
We can see that the save is properly done

359
00:16:16.219 --> 00:16:19.580
By applying the Singleton design pattern

360
00:16:19.580 --> 00:16:22.780
and implementing the Get/Set properties

361
00:16:22.780 --> 00:16:26.700
you can create a solution that allows you to implement

362
00:16:26.700 --> 00:16:27.871
this content in such a simple way

363
00:16:28.395 --> 00:16:32.157
Memory Management Using an objectPool

364
00:16:32.900 --> 00:16:35.140
Then, this time, let's learn

365
00:16:35.140 --> 00:16:37.440
how to utilize an objectPool

366
00:16:37.440 --> 00:16:39.219
for memory management

367
00:16:39.219 --> 00:16:41.020
An objectPool is

368
00:16:41.020 --> 00:16:45.419
a technique where, as I mentioned before

369
00:16:45.419 --> 00:16:48.769
when shooting bullets, you take the bullets from the magazine

370
00:16:48.769 --> 00:16:49.918
and use them

371
00:16:51.700 --> 00:16:54.340
There will be two places where the objectPool is used

372
00:16:54.340 --> 00:16:57.900
The first place is where the bullets are created

373
00:16:57.900 --> 00:16:59.460
The bullets are being created where?

374
00:16:59.460 --> 00:17:00.966
in the PlayerFire.cs file

375
00:17:00.966 --> 00:17:03.659
a bullet is fired whenever it's needed

376
00:17:03.659 --> 00:17:07.260
So, here, let's create a magazine where

377
00:17:07.260 --> 00:17:09.540
we can use the objectPool

378
00:17:09.540 --> 00:17:15.660
Let's first name this the objectPool Magazine

379
00:17:15.660 --> 00:17:21.099
Then, let's add the number of bullets to be placed in the magazine here

380
00:17:21.099 --> 00:17:25.370
Next, let's create an objectPool array

381
00:17:25.370 --> 00:17:33.060
corresponding to this magazine

382
00:17:33.060 --> 00:17:35.939
Then, this will be the size of the array

383
00:17:35.939 --> 00:17:39.780
So, let's add public int poolSize for that

384
00:17:39.780 --> 00:17:43.380
The name will be poolSize, and the value will be set to 10

385
00:17:43.380 --> 00:17:45.660
That means the magazine will hold 10 bullets

386
00:17:45.660 --> 00:17:49.380
The size of this array will be the value you set

387
00:17:49.380 --> 00:17:52.430
So, you will add GameObject

388
00:17:52.430 --> 00:17:54.420
and then insert the array like this

389
00:17:54.420 --> 00:17:57.620
And then, you will name it

390
00:17:57.620 --> 00:18:00.459
bulletObjectPool like this

391
00:18:00.459 --> 00:18:04.099
So, when do we add bullets to this magazine?

392
00:18:04.099 --> 00:18:07.459
At the start, we create all the bullets at once

393
00:18:07.459 --> 00:18:09.339
Then, when we fire bullets during the game

394
00:18:09.339 --> 00:18:12.180
we can take them from the magazine and shoot them

395
00:18:12.180 --> 00:18:20.339
So, when it is created, to the objectPool

396
00:18:20.339 --> 00:18:23.699
which is the magazine

397
00:18:23.699 --> 00:18:29.060
it will generate and add one bullet at a time

398
00:18:29.060 --> 00:18:31.300
Let's go ahead and implement this

399
00:18:31.300 --> 00:18:34.380
The first step is when it is created, so we will do it in the Start function

400
00:18:34.380 --> 00:18:37.130
And ultimately, what we want to do is

401
00:18:37.130 --> 00:18:39.619
add bullets to the magazine

402
00:18:39.619 --> 00:18:43.300
want to add bullets to the objectPool

403
00:18:43.300 --> 00:18:46.540
This is our ultimate goal

404
00:18:46.540 --> 00:18:53.221
Then, the second step is to generate the bullets in the bullet factory

405
00:18:56.300 --> 00:19:00.500
And how many bullets should be generated in the bullet factory?

406
00:19:00.500 --> 00:19:03.395
We need to generate 10 of them in total

407
00:19:03.395 --> 00:19:09.565
So, you need to loop to create as many bullets as the number of bullets according to magazine capacity

408
00:19:12.099 --> 00:19:13.459
So, what do we do?

409
00:19:13.459 --> 00:19:19.559
You need to first create the magazine

410
00:19:19.559 --> 00:19:21.979
with a size that can hold the bullets

411
00:19:21.979 --> 00:19:27.180
Then, if you do it in order, it will work like this

412
00:19:27.180 --> 00:19:30.020
Create the magazine with the appropriate size

413
00:19:30.020 --> 00:19:32.620
Then loop through the size of the magazine

414
00:19:32.620 --> 00:19:34.540
and create one bullet at a time

415
00:19:34.540 --> 00:19:38.260
What do you do? add it to the magazine

416
00:19:38.260 --> 00:19:42.859
So, first, I'll create the size for the magazine here

417
00:19:42.859 --> 00:19:46.819
So, you will create an array by adding

418
00:19:46.819 --> 00:19:49.780
new GameObject to bulletObjectPool

419
00:19:49.780 --> 00:19:56.540
The size of the array will be equal to poolSize

420
00:19:56.540 --> 00:19:59.780
Then, for the second step

421
00:19:59.780 --> 00:20:01.699
you need to loop and repeat the process

422
00:20:01.699 --> 00:20:05.859
Repeating means using a loop, a for loop would be appropriate

423
00:20:05.859 --> 00:20:09.109
int i equal to 0 how many i?

424
00:20:09.109 --> 00:20:12.099
so the loop will run timed by poolSize

425
00:20:12.099 --> 00:20:14.339
i++

426
00:20:14.339 --> 00:20:16.979
Each time, you can create one bullet

427
00:20:16.979 --> 00:20:19.292
and add it to the objectPool

428
00:20:22.420 --> 00:20:24.540
Where do we create the bullets?

429
00:20:24.540 --> 00:20:28.660
Currently, when the fire button is pressed

430
00:20:28.660 --> 00:20:31.241
bullets are created and placed like this

431
00:20:31.241 --> 00:20:32.500
that's what we've done so far

432
00:20:32.500 --> 00:20:34.420
Do you know the part where the bullet is created?

433
00:20:34.420 --> 00:20:36.870
You can press Ctrl and C to copy it

434
00:20:36.870 --> 00:20:38.819
and then paste it here

435
00:20:38.819 --> 00:20:44.713
Then, this part becomes the bullet creation in the bullet factory

436
00:20:44.713 --> 00:20:47.540
Next, you want to add the bullet to the objectPool

437
00:20:47.540 --> 00:20:48.859
That means you want to add it to the array

438
00:20:48.859 --> 00:20:51.441
So at bulletObjectPool

439
00:20:51.441 --> 00:20:54.990
Which order? at i-th position

440
00:20:54.990 --> 00:20:58.859
let's add the created bullet to the pool like this

441
00:20:58.859 --> 00:21:02.819
After saving it, when you go and press the play button, right?

442
00:21:02.819 --> 00:21:06.780
Then, all the bullets will fire at once

443
00:21:06.780 --> 00:21:08.979
How is it? they all releases at once

444
00:21:08.979 --> 00:21:11.060
This is not what we want

445
00:21:11.060 --> 00:21:14.739
So, instead of automatically flying out at the start

446
00:21:14.739 --> 00:21:17.260
we want to disable the bullet

447
00:21:17.260 --> 00:21:20.310
by setting its SetActive to false

448
00:21:20.310 --> 00:21:21.979
This will deactivate the bullet

449
00:21:21.979 --> 00:21:24.500
preventing it from moving or performing any actions

450
00:21:24.500 --> 00:21:26.339
Let's go and see what happens

451
00:21:26.339 --> 00:21:28.140
Click play button

452
00:21:28.140 --> 00:21:32.740
Then, you can see that a total of 10 bullets

453
00:21:32.740 --> 00:21:35.180
have been created from here to here

454
00:21:35.180 --> 00:21:36.579
and It is disabled

455
00:21:36.579 --> 00:21:39.060
So, when we press the fire button

456
00:21:39.060 --> 00:21:42.160
we can check each one

457
00:21:42.160 --> 00:21:44.380
and make it fly one by one

458
00:21:44.380 --> 00:21:47.630
Now, let's go ahead and implement

459
00:21:47.630 --> 00:21:50.819
the part where we fire the bullet

460
00:21:50.819 --> 00:21:55.420
Until now, when the user presses the fire button

461
00:21:55.420 --> 00:21:58.939
we created a bullet and set its position

462
00:21:58.939 --> 00:22:02.060
Now, how should this part be modified?

463
00:22:02.060 --> 00:22:12.500
Exactly, now we need to take a bullet from the magazine and fire it

464
00:22:12.500 --> 00:22:15.819
However, when we take a bullet from the magazine and fire it

465
00:22:15.819 --> 00:22:19.979
you'll see that we fired one bullet

466
00:22:19.979 --> 00:22:24.020
This is the screen, and we fired one bullet here

467
00:22:24.020 --> 00:22:24.939
So, it is flying now

468
00:22:24.939 --> 00:22:28.060
It's flying, and then you fired another bullet

469
00:22:28.060 --> 00:22:32.219
Should it fly again? No

470
00:22:32.219 --> 00:22:36.020
Exactly, we shouldn't suddenly take it and shoot it again from here

471
00:22:36.020 --> 00:22:38.619
At the very least, we need to wait until the bullet leaves the screen

472
00:22:38.619 --> 00:22:40.519
before we can take it back and fire it again

473
00:22:40.519 --> 00:22:42.140
or perform similar tasks

474
00:22:42.140 --> 00:22:45.219
In other words, we shouldn't reuse a bullet

475
00:22:45.219 --> 00:22:48.660
that is already activated and flying

476
00:22:48.660 --> 00:22:50.619
the deactivated ones

477
00:22:50.619 --> 00:22:53.459
We need to make sure that only the deactivated ones

478
00:22:53.459 --> 00:22:55.660
are taken and fired from here

479
00:22:55.660 --> 00:22:57.099
If all the bullets are already created

480
00:22:57.099 --> 00:23:00.979
meaning there are 10 bullets

481
00:23:00.979 --> 00:23:04.060
and they're already prepared

482
00:23:04.060 --> 00:23:06.979
you won't be able to shoot if there are no more available bullets

483
00:23:06.979 --> 00:23:11.322
In that case, you would need to increase the size of the magazine or perform a similar task

484
00:23:11.322 --> 00:23:13.060
Fortunately, after shooting all the bullets

485
00:23:13.060 --> 00:23:16.060
this one bullet went outside, and we deactivated it

486
00:23:16.060 --> 00:23:16.979
Then what happens?

487
00:23:16.979 --> 00:23:19.739
Now, we will be able to fire this bullet again

488
00:23:19.739 --> 00:23:24.420
when firing a bullet from the magazine

489
00:23:24.420 --> 00:23:29.939
the first condition that it should be deactivated and ready to be reused

490
00:23:29.939 --> 00:23:42.260
You must fire a deactivated bullet

491
00:23:42.260 --> 00:23:48.739
This means that we are activating the bullet again

492
00:23:48.739 --> 00:23:51.420
Let's go ahead and implement this

493
00:23:51.420 --> 00:23:53.180
When taking a bullet from the magazine to fire

494
00:23:53.180 --> 00:23:54.420
it should be a deactivated bullet

495
00:23:54.420 --> 00:23:58.697
Then, we need to loop through the entire magazine

496
00:23:58.697 --> 00:24:00.819
Start with for function

497
00:24:00.819 --> 00:24:02.819
int i = 0

498
00:24:02.819 --> 00:24:07.140
Since it's the same as above, let's copy it

499
00:24:07.140 --> 00:24:14.260
if we copy it inside this function, it will work as expected

500
00:24:14.260 --> 00:24:16.979
let's try adding it up to this point for now

501
00:24:16.979 --> 00:24:19.140
this should also be inside the for loop

502
00:24:19.140 --> 00:24:20.579
but we can do that later

503
00:24:20.579 --> 00:24:22.819
let's see what happens

504
00:24:22.819 --> 00:24:26.140
First, we need to figure out if it's deactivated bullet or not

505
00:24:26.140 --> 00:24:26.819
How do we do it?

506
00:24:26.819 --> 00:24:29.939
if i-th bullet in the ObjectPool

507
00:24:29.939 --> 00:24:36.020
if bulletObjectPool

508
00:24:36.020 --> 00:24:40.500
the i-th bullet

509
00:24:40.500 --> 00:24:43.939
if it's deactivated, let's process it

510
00:24:43.939 --> 00:24:47.459
let's place it in a way that's easier to understand first

511
00:24:47.459 --> 00:24:49.300
Let's first take one bullet

512
00:24:49.300 --> 00:24:52.619
So, we can place it as GameObject bullet

513
00:24:52.619 --> 00:24:55.900
and then position it like this

514
00:24:55.900 --> 00:24:58.339
Let's move it into the for loop as well

515
00:24:58.339 --> 00:25:00.939
When this is done

516
00:25:00.939 --> 00:25:02.819
for deactivated bullet

517
00:25:02.819 --> 00:25:05.500
you can check if the bullet is currently activated

518
00:25:05.500 --> 00:25:08.619
or deactivated by asking it

519
00:25:08.619 --> 00:25:12.699
Bullet, dot give me activeSelf

520
00:25:12.699 --> 00:25:15.780
This will tell us whether it is

521
00:25:15.780 --> 00:25:17.780
currently active or inactive

522
00:25:17.780 --> 00:25:20.099
If it is true, it means the bullet is activated

523
00:25:20.099 --> 00:25:22.660
and if it is false, it means the bullet is deactivated

524
00:25:22.660 --> 00:25:24.220
What is this value?

525
00:25:24.220 --> 00:25:26.260
since it is deactivated, it will be false

526
00:25:26.260 --> 00:25:30.339
What do we want to do here?

527
00:25:30.339 --> 00:25:34.219
What we want to do is this part

528
00:25:34.219 --> 00:25:37.939
after firing, placing the bullet at the muzzle's position

529
00:25:37.939 --> 00:25:42.540
First, let's place the bullet at the muzzle's position

530
00:25:42.540 --> 00:25:45.819
So, you set the bullet's position and then activate it

531
00:25:45.819 --> 00:25:49.469
Bullet.SetActive then true

532
00:25:49.469 --> 00:25:53.180
It would be activated then

533
00:25:53.180 --> 00:25:55.180
So, now we've already fired

534
00:25:55.180 --> 00:25:57.579
Do we have to continue to figure out?

535
00:25:57.579 --> 00:25:59.300
You need to shoot only once

536
00:25:59.300 --> 00:26:06.664
We can use break to exit the for loop

537
00:26:06.664 --> 00:26:10.430
Let's save it see what happens

538
00:26:16.020 --> 00:26:19.109
As you can see, initially, the bullets are all

539
00:26:19.109 --> 00:26:21.900
in a deactivated state when they start

540
00:26:21.900 --> 00:26:23.060
Let me fire one

541
00:26:27.099 --> 00:26:30.299
after bang bang bang, suddenly

542
00:26:30.299 --> 00:26:31.900
there are only 7 bullets left

543
00:26:31.900 --> 00:26:35.660
It seems that an error has occurred, as seen in the console window

544
00:26:35.660 --> 00:26:38.099
Why does this happen, MissingReferenceException?

545
00:26:38.099 --> 00:26:40.819
Let's double click it to expand it

546
00:26:40.819 --> 00:26:42.619
This part is where an error occurred

547
00:26:42.619 --> 00:26:45.180
What this means is that when we collide with the enemy

548
00:26:45.180 --> 00:26:48.619
we're handling the situation where both

549
00:26:48.619 --> 00:26:49.660
the enemy and the player die

550
00:26:49.660 --> 00:26:52.140
In other words, we made them disappear from the world

551
00:26:52.140 --> 00:26:54.260
they were completely removed

552
00:26:54.260 --> 00:26:57.310
But when I try to use it, it says

553
00:26:57.310 --> 00:27:00.402
It's not there

554
00:27:00.402 --> 00:27:04.300
Do you understand the point of the issue?

555
00:27:04.300 --> 00:27:06.600
Then, when it collides with an enemy

556
00:27:06.600 --> 00:27:09.020
or when it collides with the DestryZone

557
00:27:09.020 --> 00:27:11.339
If it's a bullet, what should we do?

558
00:27:11.339 --> 00:27:16.180
We would need to add it back to the magazine

559
00:27:16.180 --> 00:27:18.656
In the Enemy OnCollisionEnter

560
00:27:18.656 --> 00:27:24.140
after reviewing where that both the enemy and the bullet are involved

561
00:27:24.140 --> 00:27:29.420
if it's a bullet, what should we do?

562
00:27:29.420 --> 00:27:33.865
Then we should add it back

563
00:27:33.865 --> 00:27:35.398
if we don't, Players and other objects

564
00:27:35.398 --> 00:27:37.860
will disappear

565
00:27:37.860 --> 00:27:39.819
and in order to figure out it's a bullet

566
00:27:39.819 --> 00:27:41.060
we need to proceed with this first

567
00:27:41.060 --> 00:27:45.619
if, the one collided, other

568
00:27:45.619 --> 00:27:50.099
We took a look at the name of other.gameObject

569
00:27:50.099 --> 00:27:52.945
If the name contains Bullet

570
00:27:52.945 --> 00:27:55.660
if the name includes Bullet

571
00:27:55.660 --> 00:27:57.459
what do we do when there's Bullet?

572
00:27:57.459 --> 00:27:59.219
It is Bullet

573
00:27:59.219 --> 00:28:01.380
What do we do?

574
00:28:01.380 --> 00:28:03.300
Let's deactivate it

575
00:28:03.300 --> 00:28:07.819
So, let's deactivate this

576
00:28:07.819 --> 00:28:09.939
This is the process of loading the magazine

577
00:28:09.939 --> 00:28:16.859
so, use other.gameObject.SetActive and false

578
00:28:16.859 --> 00:28:26.619
Otherwise, from else, use Destroy

579
00:28:26.619 --> 00:28:29.500
With this set up, when the colliding object is Bullet

580
00:28:29.500 --> 00:28:31.260
it will deactivate and put it back to the magazine

581
00:28:31.260 --> 00:28:33.540
or, it will be destroyed

582
00:28:33.540 --> 00:28:36.060
set this value like this

583
00:28:36.060 --> 00:28:38.260
Which other part should it go into?

584
00:28:38.260 --> 00:28:41.219
We shall set one up for DestroyZone, too

585
00:28:41.219 --> 00:28:45.184
Let me choose this part here like this

586
00:28:45.184 --> 00:28:46.819
Ctrl and C

587
00:28:46.819 --> 00:28:49.569
Comeback to DestroyZone

588
00:28:49.569 --> 00:28:51.339
Want to destroy one that's colliding

589
00:28:51.339 --> 00:28:56.699
Ctrl and V to this part

590
00:28:56.699 --> 00:28:59.180
If the object that collided is a bullet, we should deactivate it

591
00:28:59.180 --> 00:29:01.619
If it's not a bullet, we should destroy it

592
00:29:01.619 --> 00:29:03.180
That's that

593
00:29:03.180 --> 00:29:04.870
Let's play a bit

594
00:29:04.870 --> 00:29:05.870
Play

595
00:29:11.140 --> 00:29:13.577
So far, we've managed to create the bullets

596
00:29:13.577 --> 00:29:15.500
and set them up with an objectPool

597
00:29:15.500 --> 00:29:18.140
Now, let's handle the enemies in the same way

598
00:29:18.140 --> 00:29:22.260
and set them up with an objectPool as well

599
00:29:22.260 --> 00:29:24.739
To make EnemyObjectPool

600
00:29:24.739 --> 00:29:26.820
Currently, as we can see, the EnemyManager is handling

601
00:29:26.820 --> 00:29:31.060
these tasks for each Enemy

602
00:29:31.060 --> 00:29:33.780
Here, we have the EnemyManager as shown

603
00:29:33.780 --> 00:29:36.420
If each EnemyManager has its own objectPool

604
00:29:36.420 --> 00:29:37.900
it could become difficult to manage

605
00:29:37.900 --> 00:29:39.939
So, we'll use a single EnemyManager and

606
00:29:39.939 --> 00:29:43.189
let the others just reference the position where they should be created

607
00:29:43.189 --> 00:29:45.459
allowing them to use the same objectPool

608
00:29:45.459 --> 00:29:47.659
So, let's have it be used

609
00:29:47.659 --> 00:29:50.380
with the name of SpawnPoint

610
00:29:50.380 --> 00:29:53.619
Press Ctrl and D in EnemyManager to duplicate

611
00:29:53.619 --> 00:29:56.300
Then Enemy will be created at this position

612
00:29:56.300 --> 00:29:59.344
Let's name all the duplicates as SpawnPoint

613
00:29:59.344 --> 00:30:03.938
SpawnPoint, like this

614
00:30:03.938 --> 00:30:06.492
Change the name to SpawnPoint for all of them

615
00:30:09.632 --> 00:30:11.230
So, without the EnemyManager

616
00:30:11.230 --> 00:30:13.180
select all the others

617
00:30:13.180 --> 00:30:15.409
Enemy Manager script on the right

618
00:30:15.409 --> 00:30:19.109
shall be removed in Remove Component

619
00:30:19.109 --> 00:30:23.280
Then, there will be only one EnemyManager left

620
00:30:23.280 --> 00:30:26.280
and a Transform component

621
00:30:26.280 --> 00:30:28.833
And then, for this EnemyManager

622
00:30:28.833 --> 00:30:33.000
we will set it up so that enemies are created at the locations of these spawnpoint objects

623
00:30:33.000 --> 00:30:35.650
So the enemies will be generated based on their respective spawn points

624
00:30:35.650 --> 00:30:38.360
So let's dive into EnemyManager

625
00:30:38.360 --> 00:30:41.560
Just as before, let's set it up

626
00:30:41.560 --> 00:30:45.639
to use the objectPool in the same way as with bullets

627
00:30:45.639 --> 00:30:55.151
So, you'll create a size for the objectPool

628
00:30:55.151 --> 00:30:56.651
and then you'll also need an array for the enemies

629
00:30:56.651 --> 00:31:00.119
You can set public int poolSize

630
00:31:00.119 --> 00:31:02.728
so that 10 enemies can spawn at once

631
00:31:02.728 --> 00:31:04.328
just like bullets

632
00:31:04.328 --> 00:31:06.028
having maximum enemies of 10

633
00:31:06.028 --> 00:31:08.614
Next, let's create the objectPool array

634
00:31:08.614 --> 00:31:10.053
like this

635
00:31:10.053 --> 00:31:13.603
You can create the GameObject array

636
00:31:13.603 --> 00:31:19.199
and name it enemyObjectPool like this

637
00:31:19.199 --> 00:31:22.050
Next, there were the SpawnPoint objects where they would be created

638
00:31:22.050 --> 00:31:25.350
So, right now, you've placed 5 SpawnPoint objects

639
00:31:25.350 --> 00:31:27.639
To specify the positions of the 5 SpawnPoint objects

640
00:31:27.639 --> 00:31:29.905
Let's create a Transform array

641
00:31:29.905 --> 00:31:35.010
Here, let's store the relevant details

642
00:31:35.010 --> 00:31:37.036
for the spawnpoint objects in the array

643
00:31:37.036 --> 00:31:40.625
and we'll create a public transform array

644
00:31:40.625 --> 00:31:46.380
and name it SpawnPoint

645
00:31:46.380 --> 00:31:48.580
Shall we save it now?

646
00:31:48.580 --> 00:31:51.360
and go back to Unity

647
00:31:51.360 --> 00:31:53.560
In the EnemyManager

648
00:31:53.560 --> 00:31:55.210
you can see the Spawn Points here, right?

649
00:31:55.210 --> 00:31:56.959
The Pool Size is also set to 10

650
00:31:56.959 --> 00:31:59.859
by pressing + button, you can add one vehicle by another

651
00:31:59.859 --> 00:32:03.259
If you look at the top right of the Inspector window

652
00:32:03.259 --> 00:32:04.760
There's a lock here

653
00:32:04.760 --> 00:32:07.038
Let me lock this up

654
00:32:07.038 --> 00:32:09.438
So even if you select other objects

655
00:32:09.438 --> 00:32:11.238
if you click it, the lock stays locked

656
00:32:11.238 --> 00:32:13.240
it remains fixed on the EnemyManager

657
00:32:13.240 --> 00:32:17.040
Now, let's select the SpawnPoint and choose them all at once

658
00:32:17.040 --> 00:32:18.840
and then grab this SpawnPoint

659
00:32:18.840 --> 00:32:22.334
drag and drop it in here

660
00:32:22.334 --> 00:32:24.834
All the objects will be arranged at once

661
00:32:24.834 --> 00:32:29.039
Once this task is complete, I will unlock the lock again

662
00:32:29.039 --> 00:32:31.789
Now, let's implement it so that we can use the objectPool

663
00:32:31.789 --> 00:32:33.539
Let's implement this

664
00:32:33.539 --> 00:32:38.536
First, we need to fill the objectPool when the objects are spawned

665
00:32:38.536 --> 00:32:46.360
Let's add the data to the objectPool below here

666
00:32:46.360 --> 00:32:51.010
For that, the objectPool size needs to be created in advance

667
00:32:51.010 --> 00:32:57.039
So, for the enemyObjectPool

668
00:32:57.039 --> 00:32:58.739
how many should we add in the new GameObject

669
00:32:58.739 --> 00:33:00.636
Let's first create an array

670
00:33:00.636 --> 00:33:03.318
with the size of the Pool Size

671
00:33:03.318 --> 00:33:05.693
Then, we need to repeatedly add

672
00:33:05.693 --> 00:33:08.522
one object at a time to the pool

673
00:33:08.522 --> 00:33:15.672
for(int i=0;〈poolSize;i++)

674
00:33:15.672 --> 00:33:17.479
Let's create it repeatedly

675
00:33:17.479 --> 00:33:24.020
GameObject enemy equals Instantiate

676
00:33:24.020 --> 00:33:25.822
What should be added here?

677
00:33:25.822 --> 00:33:27.272
enemyFactory

678
00:33:27.272 --> 00:33:29.872
Actually, you don't need to write this yourself

679
00:33:29.872 --> 00:33:33.653
as this content is already in the Update

680
00:33:33.653 --> 00:33:36.836
Take this whole thing and paste it like this

681
00:33:39.080 --> 00:33:44.280
Then, let's add one object at a time to the objectPool each time

682
00:33:44.280 --> 00:33:47.808
And what do we need to do? deactivate

683
00:33:47.808 --> 00:33:49.358
This should fill in there

684
00:33:49.358 --> 00:33:54.199
So in here, enemyObjectPool

685
00:33:54.199 --> 00:33:58.182
place enemy in i-th order

686
00:34:00.039 --> 00:34:01.960
Then, deactivate it

687
00:34:01.960 --> 00:34:09.360
Deactivate by using enemy,SetActive and false

688
00:34:09.360 --> 00:34:12.210
After saving

689
00:34:12.210 --> 00:34:14.199
Let's see of enemies actually spawn

690
00:34:14.199 --> 00:34:15.735
If you press play button

691
00:34:18.200 --> 00:34:19.972
Not only the bullets, but if you scroll down

692
00:34:19.972 --> 00:34:24.072
you will also see that 10 enemies

693
00:34:24.072 --> 00:34:25.079
 are pre created

694
00:34:25.079 --> 00:34:26.168
Everything is disabled right?

695
00:34:28.737 --> 00:34:31.787
In this way, you can create enemies

696
00:34:31.787 --> 00:34:36.119
in the same way as bullets

697
00:34:36.119 --> 00:34:38.961
Next, to use it, how do we use it?

698
00:34:38.961 --> 00:34:42.369
Come down, and in the Update

699
00:34:42.369 --> 00:34:45.600
Instead of simply creating an enemy at a specific time

700
00:34:45.600 --> 00:34:46.650
what do we do now?

701
00:34:46.650 --> 00:34:49.650
we can take an enemy from the objectPool and use it when needed

702
00:34:49.650 --> 00:34:52.839
So, this part

703
00:34:52.839 --> 00:34:59.401
Take objects from ObjectPool to use

704
00:35:01.777 --> 00:35:03.927
What do we need to do first?

705
00:35:03.927 --> 00:35:06.227
We need to detect the ones that are deactivated

706
00:35:06.227 --> 00:35:13.947
So, for(int i=0;i〈poolSize;i++)

707
00:35:13.947 --> 00:35:18.297
When this is possible, we can create enemy

708
00:35:18.297 --> 00:35:22.920
Once you are done with this, make sure to move it up

709
00:35:22.920 --> 00:35:26.420
First, let's take the enemy

710
00:35:26.420 --> 00:35:30.119
and add it to gameObject

711
00:35:30.119 --> 00:35:35.839
Let me get the i-th element from enemyObjectPool like this

712
00:35:35.839 --> 00:35:38.539
This part is the same as Bullet

713
00:35:38.539 --> 00:35:43.650
Let me skip whatever we've covered before

714
00:35:43.650 --> 00:35:45.200
If it's deactivated

715
00:35:45.200 --> 00:35:48.274
we will be using only the ones

716
00:35:48.274 --> 00:35:50.079
that are deactivated in the if enemy

717
00:35:50.079 --> 00:35:53.279
enemy.activeSelf

718
00:35:53.279 --> 00:35:55.729
What is the value? When false

719
00:35:55.729 --> 00:35:59.040
it will be deactivate right away

720
00:35:59.040 --> 00:36:02.340
You can set up it's position first

721
00:36:02.340 --> 00:36:03.540
And what do we need to do for this one?

722
00:36:03.540 --> 00:36:05.640
simply just Activate it

723
00:36:05.640 --> 00:36:11.109
enemy.SetActive and true, all is good

724
00:36:11.109 --> 00:36:13.959
enemy will be activate as well

725
00:36:13.959 --> 00:36:16.059
Now that you've created one, what's the next step?

726
00:36:16.059 --> 00:36:17.909
We don't have to keep repeating, right?

727
00:36:17.909 --> 00:36:21.959
break and end the search

728
00:36:21.959 --> 00:36:24.609
By doing this, finish up the results

729
00:36:24.609 --> 00:36:26.509
and now Enemy will be utilizing

730
00:36:26.509 --> 00:36:28.320
the ObjectPool just like Bullet

731
00:36:28.320 --> 00:36:31.020
But, we haven't set up what happens when Enemy collides

732
00:36:31.020 --> 00:36:37.160
When OnCollisionEnter happens in Enemy.cs

733
00:36:37.160 --> 00:36:39.360
When OnCollisionEnter happens

734
00:36:39.360 --> 00:36:41.410
and the enemy is supposed to die

735
00:36:41.410 --> 00:36:43.040
what are we supposed to do?

736
00:36:43.040 --> 00:36:44.890
we should deactivate the enemy and return it

737
00:36:44.890 --> 00:36:47.600
to magazine or to the ObjectPool just like for Bullets

738
00:36:47.600 --> 00:36:49.800
Do not use Destroy gameObject

739
00:36:49.800 --> 00:36:57.586
How? return it to ObjectPool

740
00:36:57.586 --> 00:36:58.936
How do we handle this?

741
00:36:58.936 --> 00:37:03.286
gameObject.SetActive and false

742
00:37:03.286 --> 00:37:05.399
this way it will work fine

743
00:37:05.399 --> 00:37:09.099
we have to consider one more thing, it is the DestroyZone

744
00:37:09.099 --> 00:37:11.499
If it's a bullet, we can do it this way

745
00:37:11.499 --> 00:37:14.576
but if it's not, we destroy it

746
00:37:14.576 --> 00:37:17.526
This part shouldn't be written like this

747
00:37:17.526 --> 00:37:20.126
For Bullet or Enemy

748
00:37:20.126 --> 00:37:22.640
For both Bullet and Enemy, they need to be deactivated

749
00:37:22.640 --> 00:37:25.290
So, add or in this part

750
00:37:25.290 --> 00:37:28.600
I will copy and paste the code above here

751
00:37:28.600 --> 00:37:31.020
Name for this

752
00:37:31.020 --> 00:37:33.470
when the name contains Enemy

753
00:37:33.470 --> 00:37:35.279
then it means this is Enemy

754
00:37:35.279 --> 00:37:39.379
If it's a bullet or an enemy

755
00:37:39.379 --> 00:37:41.359
we will deactivate it

756
00:37:41.359 --> 00:37:45.963
we can add this logic to the DestroyZone

757
00:37:45.963 --> 00:37:48.480
Let's save it and see what we've got

758
00:37:48.480 --> 00:37:49.466
hit Play button

759
00:38:00.480 --> 00:38:03.280
Doesn't the enemy seem to spin around

760
00:38:03.280 --> 00:38:04.600
or come in an odd way here?

761
00:38:04.600 --> 00:38:09.839
So, select the Enemy in the Prefabs folder

762
00:38:09.839 --> 00:38:13.880
Let's open the Rigidbody section like this

763
00:38:13.880 --> 00:38:17.839
In the Rigidbody, you'll see a section called Constraints

764
00:38:17.839 --> 00:38:20.079
Here, you'll see that everything is set to Freeze

765
00:38:20.079 --> 00:38:23.229
The Freeze on Position and Rotation in the Rigidbody means

766
00:38:23.229 --> 00:38:26.200
that it prevents the object from being affected by physics

767
00:38:26.200 --> 00:38:28.030
Let's play again

768
00:38:39.428 --> 00:38:42.760
We can see that enemies generate normally

769
00:38:42.760 --> 00:38:46.010
Next, for position

770
00:38:46.010 --> 00:38:48.479
Since enemy is being generated only from this one position

771
00:38:48.479 --> 00:38:50.479
So, let's modify to have enemies created

772
00:38:50.479 --> 00:38:52.760
from the SpawnPoints

773
00:38:52.760 --> 00:38:55.810
When creating this at EnemyManager

774
00:38:55.810 --> 00:38:57.919
It is currently set to its own position

775
00:38:57.919 --> 00:39:00.623
But what do we do now?

776
00:39:00.623 --> 00:39:05.799
Let's have enemies come out from SpawnPoints

777
00:39:05.799 --> 00:39:09.130
We will set it randomly

778
00:39:09.130 --> 00:39:11.400
So, let's pick a random index

779
00:39:11.400 --> 00:39:14.550
Pick a random index with int index and then where?

780
00:39:14.550 --> 00:39:18.719
Random.Range

781
00:39:18.719 --> 00:39:25.519
from 0, spawnPoint size and length

782
00:39:25.519 --> 00:39:27.280
If we set up like this, what happens?

783
00:39:27.280 --> 00:39:32.520
From here, it will pick the corresponding value, up to -1

784
00:39:32.520 --> 00:39:34.599
Because arrays start from 0

785
00:39:34.599 --> 00:39:37.999
so bring our attention here

786
00:39:37.999 --> 00:39:40.610
instead of using the transform's position, who?

787
00:39:40.610 --> 00:39:46.352
index-th which is at spawnPoints

788
00:39:46.352 --> 00:39:47.880
We’re saying let’s take the position

789
00:39:47.880 --> 00:39:51.599
from the one we randomly selected and use it

790
00:39:51.599 --> 00:39:55.795
Now it will spawn between these spawn points

791
00:40:01.455 --> 00:40:04.822
We can see it randomly spawning from various places

792
00:40:04.822 --> 00:40:06.972
If you think it's coming out too slowly

793
00:40:06.972 --> 00:40:08.920
In this case, in EnemyManager

794
00:40:08.920 --> 00:40:12.440
the minTime and maxTime are not public

795
00:40:12.440 --> 00:40:15.320
So if you change it to public

796
00:40:15.320 --> 00:40:17.960
it will be exposed in the editor

797
00:40:17.960 --> 00:40:21.280
Save it, and let's see

798
00:40:21.280 --> 00:40:23.230
It would be good if you could adjust

799
00:40:23.230 --> 00:40:26.000
the Min Time and Max Time appropriately

800
00:40:26.000 --> 00:40:31.520
If we set it between 0.2 to 1 second, or between 2 seconds

801
00:40:31.520 --> 00:40:34.719
it could spawn very frequently in short intervals

802
00:40:39.874 --> 00:40:42.200
By making these modifications

803
00:40:42.200 --> 00:40:45.300
you will have learned how to use the enemy

804
00:40:45.300 --> 00:40:46.959
objectPool

805
00:40:46.959 --> 00:40:50.309
Now, let's look at the issues

806
00:40:50.309 --> 00:40:51.959
with using an array in this case

807
00:40:51.959 --> 00:40:53.559
Right now, the array is set to 10 elements

808
00:40:53.559 --> 00:40:55.360
but if we had 10,000

809
00:40:55.360 --> 00:40:57.599
for example, and we had to detect

810
00:40:57.599 --> 00:41:00.160
the 10,000th element in a for loop

811
00:41:00.160 --> 00:41:02.160
we would have the problem

812
00:41:02.160 --> 00:41:04.260
of the loop running 10,000 times every frame

813
00:41:04.260 --> 00:41:06.279
This kind of problem can occur

814
00:41:06.279 --> 00:41:07.560
when simply detecting the element

815
00:41:07.560 --> 00:41:11.480
So, when using an array, the detection time can become long

816
00:41:11.480 --> 00:41:14.280
and this could result in a situation where not using

817
00:41:14.280 --> 00:41:16.639
an objectPool is actually better

818
00:41:16.639 --> 00:41:19.239
This time, by using a List

819
00:41:19.239 --> 00:41:23.400
Let's improve the objectPool's search speed

820
00:41:23.400 --> 00:41:26.239
In an array, data is written in order

821
00:41:26.239 --> 00:41:30.480
 but in the case of a List, the data is stored here

822
00:41:30.480 --> 00:41:33.480
and then in the below, there's an address

823
00:41:33.480 --> 00:41:37.430
It's not written in order

824
00:41:37.430 --> 00:41:38.599
in the memory space like an array

825
00:41:38.599 --> 00:41:41.599
instead, the data scattered across different locations in memory

826
00:41:41.599 --> 00:41:45.120
So, who does this data point to?

827
00:41:45.120 --> 00:41:48.236
You can point to it like this, using its address

828
00:41:48.236 --> 00:41:50.945
And it can point to its address like this

829
00:41:53.539 --> 00:41:57.440
This is what you can consider the structure of a List

830
00:41:57.440 --> 00:41:59.360
If you want to remove it

831
00:41:59.360 --> 00:42:00.559
then how?

832
00:42:00.559 --> 00:42:03.209
If we remove this, we can just cut this List

833
00:42:03.209 --> 00:42:05.879
and switch the reference address

834
00:42:05.879 --> 00:42:09.400
And if you want to add it, you can simply add it like this

835
00:42:09.400 --> 00:42:14.279
So, the List makes adding and removing data very convenient

836
00:42:14.279 --> 00:42:18.320
So, by adding only the deactivated ones to the List

837
00:42:18.320 --> 00:42:21.639
when they are activated, we can remove them

838
00:42:21.639 --> 00:42:25.679
By constantly taking the first item, deleting it, and doing this

839
00:42:25.679 --> 00:42:28.240
the remaining items will stay in the List

840
00:42:28.240 --> 00:42:30.759
So, we only bring in and use the ones that are deactivated

841
00:42:30.759 --> 00:42:34.720
Then, after using them, add the ones that are finished to the back

842
00:42:34.720 --> 00:42:37.679
and this way, we can work very efficiently

843
00:42:37.679 --> 00:42:39.919
Even if there are 10,000 items like in a for loop

844
00:42:39.919 --> 00:42:42.000
we can create a structure that allows us to retrieve them

845
00:42:42.000 --> 00:42:43.880
through a search in a single step

846
00:42:43.880 --> 00:42:46.080
So, now we will change this part

847
00:42:46.080 --> 00:42:48.720
where we are using

848
00:42:48.720 --> 00:42:51.880
what are we going to do? change an array to a List

849
00:42:51.880 --> 00:42:54.480
So, instead of using an array

850
00:42:54.480 --> 00:42:58.479
let's change it to public List and GameObject

851
00:42:58.479 --> 00:43:02.479
and switch the array to a List

852
00:43:02.479 --> 00:43:05.600
Let's first change the bullet, not the enemy

853
00:43:05.600 --> 00:43:15.399
In PlayerFire, set it as a public List

854
00:43:15.399 --> 00:43:17.919
and then we’ve created it using a List

855
00:43:17.919 --> 00:43:21.151
So, instead of being limited to the array size

856
00:43:21.151 --> 00:43:26.279
we can create it using equal sign and new

857
00:43:26.279 --> 00:43:29.240
Now we've created the List object

858
00:43:29.240 --> 00:43:33.039
From now on, instead of specifying

859
00:43:33.039 --> 00:43:34.279
the index to insert it

860
00:43:34.279 --> 00:43:36.399
you can simply add it here

861
00:43:36.399 --> 00:43:40.899
By using the .add function with the List

862
00:43:40.899 --> 00:43:44.119
when you add the Bullet

863
00:43:44.119 --> 00:43:47.240
it will be inserted at the end of the List

864
00:43:47.240 --> 00:43:49.559
continuously adding it to the back

865
00:43:49.559 --> 00:43:50.809
You can structure it exactly like

866
00:43:50.809 --> 00:43:52.720
an array by using a List in this way

867
00:43:52.720 --> 00:43:56.440
The way you use it and retrieve items is the same as with an array

868
00:43:56.440 --> 00:43:59.000
How? You can retrieve it like this

869
00:43:59.000 --> 00:44:02.199
However, if until now you had to detect

870
00:44:02.199 --> 00:44:07.399
and find deactivated objects every time the fire button was pressed

871
00:44:07.399 --> 00:44:09.520
here you will make sure to only store what?

872
00:44:09.520 --> 00:44:12.759
Only store deactivated objects

873
00:44:12.759 --> 00:44:15.399
Already, here, the deactivated objects have been set up

874
00:44:15.399 --> 00:44:18.080
So, you only need to retrieve the first one here

875
00:44:18.080 --> 00:44:20.399
However, if the magazine is empty and there are no bullets left

876
00:44:20.399 --> 00:44:21.399
then that won't work

877
00:44:21.399 --> 00:44:26.880
So, how do we handle this part? It should be done like this

878
00:44:26.880 --> 00:44:31.735
If there are bullets in the magazine

879
00:44:31.735 --> 00:44:36.880
let's take the first bullet from it

880
00:44:36.880 --> 00:44:39.279
This way, it will work

881
00:44:39.279 --> 00:44:42.329
Why? Because this magazine will only contain

882
00:44:42.329 --> 00:44:44.119
deactivated objects

883
00:44:44.119 --> 00:44:46.931
So if you look at if there are Bullets in the magazine

884
00:44:46.931 --> 00:44:51.331
look at, if, bulletObjectPool

885
00:44:51.331 --> 00:44:52.809
We can use a function called Count

886
00:44:52.809 --> 00:44:54.659
This uses the size of the List

887
00:44:54.659 --> 00:44:56.600
to get how many are currently present

888
00:44:56.600 --> 00:44:58.959
If there are any, it would be if the size is greater than 0

889
00:44:58.959 --> 00:45:01.320
Since there are always items

890
00:45:01.320 --> 00:45:06.480
At that point, instead of using a for loop

891
00:45:06.480 --> 00:45:08.720
we can change it to an if statement

892
00:45:08.720 --> 00:45:09.640
We don't need break here

893
00:45:09.640 --> 00:45:12.119
Since we're only retrieving one

894
00:45:12.119 --> 00:45:16.959
instead of using i, we just need to get the 0th element

895
00:45:16.959 --> 00:45:19.959
And there’s no need to detect deactivated bullets

896
00:45:19.959 --> 00:45:24.440
Since only deactivated bullets will be placed here anyway

897
00:45:24.440 --> 00:45:29.480
So, I will move this part up like this

898
00:45:29.480 --> 00:45:33.279
And I will remove the part where detection is done as well

899
00:45:33.279 --> 00:45:35.480
Then things get really simple

900
00:45:35.480 --> 00:45:38.279
After retrieving the bullet and activating it

901
00:45:38.279 --> 00:45:42.600
you need to remove that bullet from the list

902
00:45:42.600 --> 00:45:51.279
Once it's activated, you can remove it from the bulletObjectPool by using Remove function

903
00:45:51.279 --> 00:45:55.440
Who? Remove the bullet

904
00:45:55.440 --> 00:45:58.359
Then, that removes the bullet from the list

905
00:45:58.359 --> 00:46:00.440
Why? Because it's been activated

906
00:46:00.440 --> 00:46:03.390
It can no longer be added to the pool

907
00:46:03.390 --> 00:46:04.959
which only contains deactivated objects

908
00:46:04.959 --> 00:46:07.760
That's why we remove it

909
00:46:07.760 --> 00:46:10.160
Now, let's check it out

910
00:46:10.160 --> 00:46:12.720
after writing it this way

911
00:46:12.720 --> 00:46:17.297
Press the play button, and it should be deactivated in the same way

912
00:46:19.119 --> 00:46:21.239
I fired a bullet

913
00:46:21.239 --> 00:46:27.320
However, if you look now, all the deactivated bullets

914
00:46:27.320 --> 00:46:28.920
have disappeared

915
00:46:28.920 --> 00:46:31.519
but if one is deactivated, it should be activated

916
00:46:31.519 --> 00:46:33.279
yet there are cases where that doesn't happen

917
00:46:33.279 --> 00:46:36.760
What’s happening is that when the enemy collides with the bullet

918
00:46:36.760 --> 00:46:39.359
it should be put back into the magazine

919
00:46:39.359 --> 00:46:41.359
but right now

920
00:46:41.359 --> 00:46:43.687
all we're doing is deactivating it

921
00:46:43.687 --> 00:46:48.279
So, we need to add the bullet back into the magazine

922
00:46:48.279 --> 00:46:52.799
Add it back into the magazine, this step is necessary

923
00:46:52.799 --> 00:46:53.920
In case of Bullet

924
00:46:53.920 --> 00:46:56.239
So, where is this magazine?

925
00:46:56.239 --> 00:46:57.640
It's in PlayerFire

926
00:46:57.640 --> 00:47:01.760
This is a component attached to Player

927
00:47:01.760 --> 00:47:05.239
So this PlayerFire is

928
00:47:05.239 --> 00:47:06.880
I would put it as Player

929
00:47:06.880 --> 00:47:09.799
We can use GameObject.Find

930
00:47:09.799 --> 00:47:12.920
 to find the Player in the world

931
00:47:12.920 --> 00:47:15.519
Among the components attached to it, which one?

932
00:47:15.519 --> 00:47:16.839
PlayerFire

933
00:47:16.839 --> 00:47:19.320
This is what we are looking for

934
00:47:19.320 --> 00:47:23.399
Who should we get it from, attached to it?

935
00:47:23.399 --> 00:47:27.040
You can use Add on bulletObjectPool

936
00:47:27.040 --> 00:47:28.320
to add the bullet

937
00:47:28.320 --> 00:47:30.200
Now, you can add this bullet

938
00:47:30.200 --> 00:47:35.359
By simply inserting the gameObject into other

939
00:47:35.359 --> 00:47:36.640
since it is deactivated

940
00:47:36.640 --> 00:47:39.880
this will complete the task of putting it back into the magazine

941
00:47:39.880 --> 00:47:42.399
save it now

942
00:47:42.399 --> 00:47:45.399
he same issue would occur when the bullet collides

943
00:47:45.399 --> 00:47:47.600
with the DestroyZone

944
00:47:47.600 --> 00:47:50.519
You can press Ctrl and C

945
00:47:50.519 --> 00:47:53.519
and then add it to the DestroyZone as well

946
00:47:53.519 --> 00:47:56.040
in the OnTriggerEnter of the DestroyZone

947
00:47:56.040 --> 00:47:58.440
you perform these actions

948
00:47:58.440 --> 00:47:59.359
when it's a Bullet or an Enemy

949
00:47:59.359 --> 00:48:01.559
It seems like there’s a need to separate

950
00:48:01.559 --> 00:48:02.920
and handle these tasks

951
00:48:02.920 --> 00:48:08.559
So I would close this OR part

952
00:48:08.559 --> 00:48:13.052
After placing it like this, using else

953
00:48:13.052 --> 00:48:19.000
or else if to modify it again

954
00:48:19.000 --> 00:48:22.079
For the bullet case, we can do it like this

955
00:48:22.079 --> 00:48:25.760
Since deactivating them is the same for both

956
00:48:25.760 --> 00:48:28.200
let's handle it like this

957
00:48:28.200 --> 00:48:31.079
For the enemy case, we haven't handled it yet

958
00:48:31.079 --> 00:48:34.029
For the bullet case, this task of reassigning it

959
00:48:34.029 --> 00:48:35.799
to the player is necessary

960
00:48:35.799 --> 00:48:37.320
Now, save

961
00:48:37.320 --> 00:48:40.440
In the Enemy, this part of adding it to the magazine

962
00:48:40.440 --> 00:48:42.159
In the DestroyZone, the part

963
00:48:42.159 --> 00:48:43.760
where we currently add to the magazine

964
00:48:43.760 --> 00:48:45.119
is handled like this

965
00:48:45.119 --> 00:48:49.104
Save the changes, and then go ahead and test it again

966
00:49:03.170 --> 00:49:05.559
It seems like the part is working correctly now

967
00:49:05.559 --> 00:49:07.559
But we have a problem here

968
00:49:07.559 --> 00:49:10.760
If you click on it, what issues do you see?

969
00:49:10.760 --> 00:49:12.919
It says we have an error, here

970
00:49:12.919 --> 00:49:14.919
It seems like the error

971
00:49:14.919 --> 00:49:17.880
we are encountering is a null reference error

972
00:49:17.880 --> 00:49:19.440
what is a null?

973
00:49:19.440 --> 00:49:21.080
In here, what null is

974
00:49:21.080 --> 00:49:24.159
This happens when you're trying to retrieve a value from ones that don't exist

975
00:49:24.159 --> 00:49:25.919
Exactly, since the player has died

976
00:49:25.919 --> 00:49:27.320
after colliding with the enemy

977
00:49:27.320 --> 00:49:29.159
But it is already dead

978
00:49:29.159 --> 00:49:30.719
but trying to access the PlayerFire component

979
00:49:30.719 --> 00:49:33.880
We cannot retrieve the component of an already dead object

980
00:49:33.880 --> 00:49:34.760
Nope

981
00:49:34.760 --> 00:49:37.660
So, this part needs to be handled

982
00:49:37.660 --> 00:49:40.760
by detecting it beforehand

983
00:49:40.760 --> 00:49:43.719
Sure, let's try modifying the code here a bit

984
00:49:43.719 --> 00:49:48.840
Let's first create a GameObject and add it here

985
00:49:48.840 --> 00:49:52.719
Let's name it "player" and proceed

986
00:49:52.719 --> 00:49:54.559
Position it like this

987
00:49:54.559 --> 00:49:57.479
Let's change the name of the object here to pf

988
00:49:57.479 --> 00:49:59.440
Since it's PlayerFire

989
00:49:59.440 --> 00:50:02.640
Let's change it like this

990
00:50:02.640 --> 00:50:07.440
Now, retrieve the component from this player object

991
00:50:07.440 --> 00:50:09.919
this is what we are going to have

992
00:50:09.919 --> 00:50:11.359
Found the Player now

993
00:50:11.359 --> 00:50:13.799
Then, retrieve the PlayerFire component from the player

994
00:50:13.799 --> 00:50:15.359
Yes, isn't this the same issue?

995
00:50:15.359 --> 00:50:20.640
But here, if the player exists

996
00:50:20.640 --> 00:50:23.440
we can add a check to detect it like this

997
00:50:23.440 --> 00:50:26.817
You can handle it like this

998
00:50:29.520 --> 00:50:32.919
so that the code inside the

999
00:50:32.919 --> 00:50:35.359
if block only runs when the player exists

1000
00:50:35.359 --> 00:50:38.559
Only to be handled when the player exists

1001
00:50:38.559 --> 00:50:41.520
the same issue would occur with the enemy as well

1002
00:50:41.520 --> 00:50:43.970
Let's take, add Bullet into the magazine

1003
00:50:43.970 --> 00:50:45.400
Ctrl and C

1004
00:50:45.400 --> 00:50:48.880
Just like Player, when Enemy dies

1005
00:50:48.880 --> 00:50:50.679
we are not supposed to handle this

1006
00:50:50.679 --> 00:50:52.644
add Bullet into the magazine, this part

1007
00:50:52.644 --> 00:50:54.559
change it like this

1008
00:50:54.559 --> 00:50:57.000
Save it and then run test again

1009
00:50:57.000 --> 00:50:59.799
Now, we should be able to see that the issue has been resolved

1010
00:51:07.799 --> 00:51:10.000
We don't get the error message at all

1011
00:51:10.000 --> 00:51:12.146
So like this

1012
00:51:12.146 --> 00:51:15.599
We've tried changing the objectPool to use a List

1013
00:51:15.599 --> 00:51:18.599
The same work can be done for the enemy as well

1014
00:51:18.599 --> 00:51:22.903
In EnemyManager, you can change it like this

1015
00:51:22.903 --> 00:51:24.640
and switch it to a List

1016
00:51:24.640 --> 00:51:30.090
Then, you can simply use new

1017
00:51:30.090 --> 00:51:33.200
and add it like this

1018
00:51:33.200 --> 00:51:35.400
Next, instead of directly

1019
00:51:35.400 --> 00:51:36.799
assigning the enemy with equal sign

1020
00:51:36.799 --> 00:51:39.599
and use Add function

1021
00:51:39.599 --> 00:51:42.599
change it to add the enemy in the form of an addition

1022
00:51:42.599 --> 00:51:45.880
It's exactly the same as adding the bullet

1023
00:51:45.880 --> 00:51:49.280
Then, move down and update it so that after a certain amount of time

1024
00:51:49.280 --> 00:51:51.239
we have the process of detecting

1025
00:51:51.239 --> 00:51:56.389
So, when it's in the magazine or objectPool

1026
00:51:56.389 --> 00:52:01.378
objectPool

1027
00:52:01.378 --> 00:52:08.078
use if and enemyObjectPool.Count

1028
00:52:08.078 --> 00:52:09.880
What do we want to do?

1029
00:52:09.880 --> 00:52:12.880
Instead of using a for loop

1030
00:52:12.880 --> 00:52:16.200
we just retrieve the 0th element

1031
00:52:16.200 --> 00:52:19.119
and is there any need to check if it's deactivated?

1032
00:52:19.119 --> 00:52:23.159
No, therefore move it outside of the if statement and remove the if block

1033
00:52:23.159 --> 00:52:28.559
 you can remove the if statement like this

1034
00:52:28.559 --> 00:52:32.479
And finally, you should remove

1035
00:52:32.479 --> 00:52:36.320
the enemy from the enemy objectPool

1036
00:52:36.320 --> 00:52:40.960
So, use enemyObjectPool.Remove

1037
00:52:40.960 --> 00:52:43.660
to remove Who? the enemy

1038
00:52:43.660 --> 00:52:47.280
from the objectPool like this

1039
00:52:47.280 --> 00:52:52.200
Great! Now, when it collides

1040
00:52:52.200 --> 00:52:54.352
When the enemy dies, what happens?

1041
00:52:54.352 --> 00:52:57.479
we need to add it back to the objectPool in the same way

1042
00:52:57.479 --> 00:53:01.679
Enemies can't collide with each other

1043
00:53:01.679 --> 00:53:05.359
so this part needs to be handled accordingly

1044
00:53:05.359 --> 00:53:09.039
this should only be handled in the DestroyZone

1045
00:53:09.039 --> 00:53:12.200
At this point, the enemy will be deactivated

1046
00:53:12.200 --> 00:53:14.320
but where is it in the objectPool?

1047
00:53:14.320 --> 00:53:15.520
It's in the EnemyManager

1048
00:53:15.520 --> 00:53:18.400
If you add it to the EnemyManager

1049
00:53:18.400 --> 00:53:21.880
it will make the process easier to manage

1050
00:53:21.880 --> 00:53:26.000
if you make it a singleton design pattern, it will be easier to manage and access

1051
00:53:26.000 --> 00:53:28.359
I will just let you guys figure that part out

1052
00:53:28.359 --> 00:53:31.159
We will take the content here and

1053
00:53:31.159 --> 00:53:35.159
use it by simply changing the name

1054
00:53:35.159 --> 00:53:36.880
Deactivate

1055
00:53:36.880 --> 00:53:41.400
This time, instead of the magazine, what instead?

1056
00:53:41.400 --> 00:53:45.479
Enemy, enemyObjectPool

1057
00:53:45.479 --> 00:53:47.559
This time, we are looking for whom?

1058
00:53:47.559 --> 00:53:50.080
we need to find EnemyManager

1059
00:53:50.080 --> 00:53:53.159
The one in the EnemyManager

1060
00:53:53.159 --> 00:53:55.000
let's put it as em

1061
00:53:55.000 --> 00:53:59.960
Since it's EnemyManger, right?

1062
00:53:59.960 --> 00:54:06.239
Who do we need to get inside EnemyManager?

1063
00:54:06.239 --> 00:54:09.799
You need to retrieve the EnemyManager class

1064
00:54:09.799 --> 00:54:11.840
this component

1065
00:54:11.840 --> 00:54:14.960
get EnemyManager component

1066
00:54:14.960 --> 00:54:17.880
We can keep the variable as pf as it is

1067
00:54:17.880 --> 00:54:21.000
This would now be which, not bulletObjectPool?

1068
00:54:21.000 --> 00:54:25.960
enemyObjectPool

1069
00:54:25.960 --> 00:54:30.892
If it’s a bit confusing, you can refer to it as manager

1070
00:54:30.892 --> 00:54:32.440
Great

1071
00:54:32.440 --> 00:54:33.760
We just changed the name here

1072
00:54:33.760 --> 00:54:35.320
It’s exactly the same as the upper part

1073
00:54:35.320 --> 00:54:38.280
By simply changing the name, get GameObject

1074
00:54:38.280 --> 00:54:39.680
then get the EnemyManager component

1075
00:54:39.680 --> 00:54:41.799
attached to that GameObject

1076
00:54:41.799 --> 00:54:43.599
Afterward, we access the objectPool attached to it

1077
00:54:43.599 --> 00:54:46.191
and complete the task in this way

1078
00:54:48.963 --> 00:54:51.400
So, we've learned how to retrieve

1079
00:54:51.400 --> 00:54:53.719
deactivate, and add it back to the enemy objectPool

1080
00:54:53.719 --> 00:54:57.190
completing the entire process

1081
00:54:57.190 --> 00:54:59.808
Let's save and find out if it works

1082
00:55:25.039 --> 00:55:30.359
Now, you can see that the enemies are coming in like this

1083
00:55:30.359 --> 00:55:32.320
then it stops coming in

1084
00:55:32.320 --> 00:55:33.479
we've got ourselves a problem here

1085
00:55:33.479 --> 00:55:36.880
Let’s take a look at what issues might be present

1086
00:55:36.880 --> 00:55:39.320
When the EnemyManager is created

1087
00:55:39.320 --> 00:55:43.200
In the DestroyZone

1088
00:55:43.200 --> 00:55:46.400
when the enemy collides with it

1089
00:55:46.400 --> 00:55:48.520
it's correctly added back into the objectPool

1090
00:55:48.520 --> 00:55:54.320
When the enemy collides with a bullet or the player

1091
00:55:54.320 --> 00:55:56.320
is there a part where it's added back to the objectPool?

1092
00:55:56.320 --> 00:56:00.440
We have none, when the bullet hits the enemy

1093
00:56:00.440 --> 00:56:02.400
there's currently no possibility for that enemy to be recreated

1094
00:56:02.400 --> 00:56:03.880
or added back to the objectPool

1095
00:56:03.880 --> 00:56:07.400
because the enemy isn't being added back to the objectPool

1096
00:56:07.400 --> 00:56:09.919
So, this part in the DestroyZone

1097
00:56:09.919 --> 00:56:13.039
if it collided with a Bullet

1098
00:56:13.039 --> 00:56:15.640
 for the enemy when it collides with a bullet

1099
00:56:15.640 --> 00:56:19.919
it's just deactivating enemy only

1100
00:56:19.919 --> 00:56:24.080
but what about me? what am I doing?

1101
00:56:24.080 --> 00:56:26.760
It's simply being deactivated

1102
00:56:26.760 --> 00:56:28.599
where should I add into?

1103
00:56:28.599 --> 00:56:32.080
it should be returned to the objectPool

1104
00:56:32.080 --> 00:56:34.080
So, let's take this part and place it

1105
00:56:34.080 --> 00:56:36.630
in the corresponding section of

1106
00:56:36.630 --> 00:56:38.200
Enemy.cs from DestroyZone

1107
00:56:38.200 --> 00:56:41.599
For the deactivation part, let's add it back to the objectPool

1108
00:56:41.599 --> 00:56:45.599
Ctrl and C this part

1109
00:56:45.599 --> 00:56:48.799
In Enemy.cs, after SetActive false, go ahead

1110
00:56:48.799 --> 00:56:50.799
and press Ctrl+V to paste it there

1111
00:56:50.799 --> 00:56:52.400
What happens?

1112
00:56:52.400 --> 00:56:55.440
after deactivating it, you need to bring the EnemyManager back

1113
00:56:55.440 --> 00:56:58.640
and reassign it, all the way through this process

1114
00:56:58.640 --> 00:57:00.000
worked right?

1115
00:57:00.000 --> 00:57:02.799
In the OnCollisionEnter section of the Enemy

1116
00:57:02.799 --> 00:57:06.440
the enemy itself is not currently being added back

1117
00:57:06.440 --> 00:57:08.159
to the objectPool at the end

1118
00:57:08.159 --> 00:57:11.160
So, you can add that part here to ensure the enemy is added back

1119
00:57:11.160 --> 00:57:13.330
Save and go play

1120
00:57:16.359 --> 00:57:18.076
before pressing play, for testing

1121
00:57:18.076 --> 00:57:20.976
You can try setting the objectPool size

1122
00:57:20.976 --> 00:57:22.920
to just 3 for now

1123
00:57:22.920 --> 00:57:24.814
When you play

1124
00:57:27.239 --> 00:57:29.880
the objectPool will contain 3 objects

1125
00:57:29.880 --> 00:57:33.479
What happens if I shoot once

1126
00:57:33.479 --> 00:57:34.252
Now

1127
00:57:37.885 --> 00:57:40.319
It seems that in the objectPool

1128
00:57:40.319 --> 00:57:42.319
other objects besides the enemy are

1129
00:57:42.319 --> 00:57:44.040
being added to the enemy objectPool

1130
00:57:44.040 --> 00:57:47.800
If you look, Bullet is added

1131
00:57:47.800 --> 00:57:50.884
We see that bullets are being added to the objectPool as well

1132
00:57:53.280 --> 00:57:54.400
Why is this happening?

1133
00:57:54.400 --> 00:57:57.119
If you take a look at code, we did something wrong

1134
00:57:57.119 --> 00:57:59.239
It looks like this happened because of a simple copy paste

1135
00:57:59.239 --> 00:58:02.160
Which do we need to return the enemy to the objectPool?

1136
00:58:02.160 --> 00:58:03.880
Instead of adding the object that collided with

1137
00:58:03.880 --> 00:58:06.830
it should add myself back to the objectPool

1138
00:58:06.830 --> 00:58:08.640
by only adding myself

1139
00:58:08.640 --> 00:58:14.009
since it's the enemy, you need to add the enemy back into the enemyObjectPool

1140
00:58:14.009 --> 00:58:15.520
We should add its own GameObject

1141
00:58:15.520 --> 00:58:19.195
not the GameObject of Other

1142
00:58:19.195 --> 00:58:22.119
Let's save it and check again

1143
00:58:22.119 --> 00:58:24.119
Play

1144
00:58:24.119 --> 00:58:25.319
All the enemies are inside now

1145
00:58:25.319 --> 00:58:26.520
Bang!

1146
00:58:26.520 --> 00:58:27.460
Now

1147
00:58:30.839 --> 00:58:32.590
Enemy comes out

1148
00:58:34.560 --> 00:58:36.880
And we see Enemy gets added back into the pool

1149
00:58:36.880 --> 00:58:38.880
We can see how it works

1150
00:58:38.880 --> 00:58:41.040
If we increase the objectPool size to 10

1151
00:58:41.040 --> 00:58:43.005
10 objects will be added at once

1152
00:58:47.199 --> 00:58:50.719
As enemies appear on the screen, the pool will gradually decrease

1153
00:58:50.719 --> 00:58:53.839
there are 8 objects in the pool, and since 2 have been used, only 8 remain available

1154
00:58:53.839 --> 00:58:56.289
So, we have learned how to implement

1155
00:58:56.289 --> 00:58:58.160
the work up to the beta version

1156
00:58:58.160 --> 00:59:01.599
I will summarize the content learned from this chapter

1157
00:59:01.599 --> 00:59:04.399
First, we learned how to create a manager

1158
00:59:04.399 --> 00:59:06.920
using the Singleton design pattern

1159
00:59:06.920 --> 00:59:08.920
We understood the Singleton design pattern

1160
00:59:08.920 --> 00:59:10.520
and learned how to implement

1161
00:59:10.520 --> 00:59:12.670
Score Manager as a Singleton object

1162
00:59:12.670 --> 00:59:15.680
using the static keyword

1163
00:59:15.680 --> 00:59:17.730
Then, using the Singleton object

1164
00:59:17.730 --> 00:59:20.319
modified the code to set the score

1165
00:59:20.319 --> 00:59:23.199
We learned how to improve code readability

1166
00:59:23.199 --> 00:59:27.199
by using the Get/Set properties in C#

1167
00:59:27.199 --> 00:59:32.319
Next, we learned about memory management using the objectPool

1168
00:59:32.319 --> 00:59:35.400
First, we implemented an objectPool using an array

1169
00:59:35.400 --> 00:59:37.599
and explored its drawbacks

1170
00:59:37.599 --> 00:59:39.400
Then, we improved the objectPool by using

1171
00:59:39.400 --> 00:59:44.439
a list data structure to enhance the search speed

1172
00:59:44.439 --> 00:59:47.339
We implemented this objectPool

1173
00:59:47.339 --> 00:59:50.760
for the creation of bullets and enemies

1174
00:59:50.760 --> 00:59:52.738
Great job so far!

1175
00:59:53.161 --> 00:59:54.051
Creating a manager using the Singleton design pattern
The Singleton design pattern
A method of registering and using only one object instance as static

1176
00:59:54.051 --> 00:59:54.911
Since ScoreManager is the only manager that handles the score, it is created as a Singleton object for use

1177
00:59:54.911 --> 00:59:55.661
I moved to the Enemy.cs script and changed it to access the Instance member of ScoreManager

1178
00:59:55.661 --> 00:59:56.552
Get, Set Property
Create a Get and Set property named Score in ScoreManager

1179
00:59:56.552 --> 00:59:57.361
Copy the implementation of the GetScore function into the getter of Score
Copy the implementation of the SetScore function into the setter of Score

1180
00:59:57.361 --> 00:59:58.156
Remove the GetScore and SetScore functions
Move to the Enemy script and change the score modification code to use the Get/Set property

1181
00:59:58.156 --> 00:59:59.169
Memory management using an objectPool
Creating a bullet objectPool
Add an objectPool size property and an array for the objectPool in PlayerFire.cs

1182
00:59:59.169 --> 01:00:00.291
Implementation order
Create a magazine with a size to hold bull
Repeat bullet creation
Create bullets
Add bullets into ObjectPool

1183
01:00:00.291 --> 01:00:01.244
Create the bulletObjectPool array with the size of the pool
Since it requires repetitive actions, implement it using a for loop in C#

1184
01:00:01.244 --> 01:00:02.270
Modify the bullet creation code in the Update function of PlayerFire to use
Deactivate the used bullet instead of removing it and return it to the mag

1185
01:00:02.270 --> 01:00:03.235
Add the same code to DestroyZone.cs as well

1186
01:00:03.235 --> 01:00:04.285
Creating an objectPool for enemies
Creating SpawnPoint
Select the EnemyManager game object and press Ctrl and D to duplicate it

1187
01:00:04.285 --> 01:00:05.335
Exclude EnemyManager and rename duplicates to SpawnPoint
Remove the EnemyManager component from all SpawnPoint objects

1188
01:00:05.335 --> 01:00:06.326
Declare a SpawnPoint array to remember the positions enemies will spawn
Create an objectPool with a size capable of holding enemies, and use a loop

1189
01:00:06.326 --> 01:00:07.285
Modify the Update function to use the objectPool and find any deactivated Enemy to activate it
Modify Enemy.cs to deactivate the Enemy

1190
01:00:07.285 --> 01:00:08.080
Add a condition in DestroyZone to deactivate the Enemy
Move to EnemyManager.cs and assign the generated enemy's position to the SpawnPoint location

1191
01:00:08.080 --> 01:00:08.872
Create an objectPool using a list
Replace the bullet objectPool with a list
Change the data type of the PlayerFire.cs object pool to List

1192
01:00:08.872 --> 01:00:09.573
Modify the Start and Update functions to use a List
Insert the bullet into the objectPool in DestroyZone.cs when it's a bullet

1193
01:00:09.573 --> 01:00:10.273
Move to the Enemy class and get the PlayerFire object to insert values into the bulletObjectPool list

1194
01:00:10.273 --> 01:00:10.986
Replace the Enemy objectPool with a list
Move to EnemyManager.cs and change GameObject enemyObjectPool to a List

1195
01:00:10.986 --> 01:00:11.656
Modify the Start function to replace object creation with a List and use the Add function to insert values

1196
01:00:11.656 --> 01:00:12.315
Modify the Update function to use a List instead of a for loop for checking
Insert the Enemy into the objectPool in DestroyZone.cs using a List

1197
01:00:12.315 --> 01:00:12.999
Move to the Enemy class and, on collision, insert the Enemy back into the EnemyManager's List objectPool