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With our enemy waves now working, it's time to start thinking of creative ways to kill our player,

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because at the moment the enemies can just pass right through them.

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And I think it would be nice before we start adding things like projectiles is to just have the player

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take damage if they collide with one of the enemies.

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So it almost becomes a game of dodge.

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To do this, we are going to need a couple of new scripts.

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But before we jump into the code side, let's set up our player and our enemy so that they can interact

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with each other over in our Prefabs folder.

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Let's click on both our enemy and our player because we're going to be setting up pretty much exactly

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the same.

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So doing it this way, we can add components to both objects rather than doing them one at a time.

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Over in our inspector, let's add some components and the first thing we need is a rigid body, 2D.

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And in here, the only thing we want to change for now is the body type.

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We want to change it from being dynamic to kinematic.

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And this is because we're moving all of our objects in code rather than relying on the physical system

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with our rigid body added.

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Let's go ahead and add another component and this time we're going to need a type of collider.

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Now there are a few different 2D colliders that we can choose from.

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So you may want to choose a box or a capsule, but I'm actually going to go with a circle.

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And the reason I've chosen a circle collider here is because I think it will nicely encapsulate our

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sprites, but depending on the sprites you're using, you may want to choose a different type of 2D

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collider with these components added to both our enemy and our player, let's just do some fine adjustments

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on each.

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So I'm going to start by going into my enemy prefab and just reducing the size of this circle.

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Collider A little bit, and I like to use the edit collider option.

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So we highlight this and then we can just drag in these nodes to change the size.

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Now this isn't an exact science and it doesn't have to be perfect, but I think somewhere around here

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is going to be okay.

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So if the player collides with the tips of these wings, the collision isn't going to be detected.

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But it can be nice just to give the player a little bit of leeway so that game doesn't feel too unfair.

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Then we're going to do the same thing on our player, so we'll open up our player prefab and again,

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just change the size of our circle collider.

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And again, I'm not being too precious about this.

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So if we happen to clip our wings, we're not going to take any damage.

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But something around here should be okay.

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After all, we can always come back and adjust these later on.

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We're not fixing any of this in stone just yet, and that will definitely be something we'd want to

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keep an eye on during our plate testing.

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So with our collider set up, there is one more thing that I've forgotten to do.

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So let's select both our enemy and our player once again.

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And if we go down into our circle Collider, we don't want these to be colliders.

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We want them to be triggers.

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And this will allow the objects to pass through one another rather than bouncing off each other.

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So with that all set up now let's think about what script we're going to need.

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Well, our player is going to need some health, so we could put that in our existing player script.

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But since our enemy is also going to need some health, I think it makes much more sense to have a dedicated

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script purely for looking after the health of an object.

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So let's create that new script.

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Lets right click Create C-sharp script and call this the Health script.

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And this is going to be attached to both our player and our enemy.

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So again, back over in our prefabs, let's select both of our prefabs.

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Scroll down and add the new health component that we've just created.

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And secondly, we're going to need a way of dealing damage to these objects that have health.

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So for now, we just want the enemy to be able to hurt the player.

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But later on, we're also going to want things like projectiles to be dealing damage as well.

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So again, it makes sense to have a dedicated script that can do this.

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And this kind of script reuse is really important in game development because it's going to save us

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a lot of time if we've got a lot of things in our game doing very similar things.

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So let's create another C-sharp script.

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And this time we're going to call it the damage dealer.

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Now to write both of these scripts, let's start off with our damage dealer, because this is going

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to be an incredibly simple script.

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It's really not going to do much at all.

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We're not going to need start and update, and all this is really going to do is hold the amount of

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damage the object that this is attached to is going to do.

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So let's create a serialized field of type int and call this the damage value or just damage in fact.

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And by default, let's give that a value of around ten.

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Next, we're going to need a getter so that other scripts can access this amount of damage that needs

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to be dealt.

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So we're just going to need a public int get damage.

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And return the damage.

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Now, we may come back and add things to this later on, but at its core, this is really all it needs

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to do.

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So let's save our script and now let's go into our health script.

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This one is going to be a little bit more complicated, but really not by much at the moment.

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So again, let's get rid of the start and update.

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And this script is going to hold the amount of health our object has.

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So let's have another serialized field of type int called health and let's maybe give that a default

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value of 50.

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Now the basic logic that we're going to be following is that our damage dealer is going to come in and

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hit the thing with health and then reduce that health by the damage amount.

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That's why we went through the trouble of adding those triggers on our objects earlier so that we can

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use the on trigger enter to DX method.

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So let's write our on trigger enter to DX method.

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This requires us to pass in a collider to DH and we'll call this the other collider.

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And in this method we want to check whether the thing we're colliding with is a damaged dealer and if

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it is, we want to take some damage.

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And there are a few different ways that we might check what the other collider is.

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We could use things like tags or layer masks and things like that.

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But what I'm going to do is I'm just going to query whether I can get the damaged dealer component off

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of that other object.

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So let's create a temporary variable or type damaged dealer and we'll call this the damage dealer.

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And this is going to be equal to the other dot get component of type damage dealer.

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So this will check the collider that we're passing in and see whether we can grab a component of type

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damage dealer.

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Now if this is successful, then our damaged deal dealer variable will hold a reference to that component.

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But if it fails, our damage dealer is going to be null.

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So now that we've tried to get our component, we can ask if our damage dealer does not equal null or

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in other words, if we do have something stored in that variable, then we want to take some damage.

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And we're also going to want to tell the damaged dealer that it actually hit something so that can destroy

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itself.

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So let's start with this second one and tell our damage dealer that it hit something and that it should

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destroy itself.

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So over in our damage dealer, let's add another public method.

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This can be void and we can just call this hit in here.

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We want to destroy our damage dealer so our enemy that we've hit or a projectile that's later going

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to be coming our way.

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And we can do that with destroy game object.

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So save our damage dealer, jump back into health and we can replace our comment here with damage dealer

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dot hit with that sorted.

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Now let's think about taking some damage and this is going to be your challenge.

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I want you to write the method for taking damage.

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This method that we're going to call take damage is going to pass in the amount of damage taken which

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we can get from our damage dealer, reduce our health by that damage amount.

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And if we run out of health, then we want to destroy the game object.

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So pause the video now and give that a go.

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Okay.

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Welcome back.

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So let's write our take damage method.

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We said this wanted to pass in the amount of damage from our damage dealer.

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So we can get that from our damage dealer.

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Don't get damage.

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So that's us calling the method, but we still need to write it.

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So underneath our on trigger enter method, let's have a void, take damage.

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And this is going to pass in an integer for the amount of damage in here.

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We want to reduce our health by the damage being taken so we can say health minus equals the damage.

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And then if our health runs out from taking this damage, we can say if our health is less than or equal

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to zero, then we want to destroy our game object.

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So we're taking a fairly simplistic approach for just destroying objects whenever they hit another object.

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But later on we will be expanding on that by adding things like a particle system and explosion sound

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and a whole bunch of other cool stuff.

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But for now, this is good enough.

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So let's save our script, head over into Unity and test this out.

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Now, before we go and hit play, we do need to add our damage dealer to our enemy.

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So in our prefabs folder let's go to our enemy prefab and add a component of type damage dealer and

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our player has been given a default health of 50, the same as our enemy.

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So let's give our damage stealer of four now a value of 25.

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This will mean we can hit two enemies before being destroyed.

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This is just for testing so we can see things in action.

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And later on I'd probably want this to be a lot higher to really incentivize the player not to touch

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the enemies.

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But for now, that should be fine.

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So let's go ahead and hit play and test this out.

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And now if we collide with an enemy, it disappears.

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And if we hit a second enemy, then both the player and the enemy get destroyed.

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So our health and our damaged dealing system is working nicely and with a few tweaks to our enemy wave

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system.

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To make it more frantic, we could have a very nice game of Dodge on our hands, but this is called

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Laser Defender.

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And what's a game of laser defender without any lasers?

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So in the next lecture, let's start adding some projectiles for the player to dodge as well and see

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how our damage dealer script can be reused for other objects in the game.

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So I'll see you there.