Challenge: Design a New Building

So far, you have created two buildings: one that fires projectiles when enemies are within its Area of Engagement and another that continuously generates Gold. In this challenge, you should define a new structure of your own choosing. Below are a few ideas to choose from.

A turret that has a larger range but longer cooldown
A turret that fires at all enemies within its Area of Engagement
A building that doubles the amount of gold of all GoldGenerates adjacent to it
A building that slows down enemies that are within its AreaOfEngagment
A building of your own design

Challenge: Add a Build Button for your new Building

Add a third button that can be used to place your new building
Enter Play Mode to test that your building works as expected
If all went well, you should have a scene that looks similar to the one below. For the demo, I've created a Cannon turret that has a wider range than the original Turret but has a longer cooldown.

BuildingData

Currently, the cost of each building is set to 50 directly in the code. To give your player more interesting choices, you can make each building have a different cost. To do this, you will create a ScriptableObject.

Defining a Scriptable Object

A ScriptableObject can be used to define and edit data in the Unity Inspector that does not exist on a Game Object.

Read the Friendly Manual: Unity - Manual: ScriptableObject
In your Scripts folder right click
Select Create > Scripting > ScriptableObject Script
Name the ScriptableObject: "BuildingData"

Open the BuildingData script
Verify that the class is named BuildingData
Verify that the class extends ScriptableObject
Verify the menuName is set to Scriptable Objects/BuildingData

Creating a Scriptable Object

Create a new folder in Assets called Data
Open the Data folder
Right click and select Create > Scriptable Objects > BuildingData
Note: The option to select Scriptable Objects > BuildingData was defined by the CreateAssetMenu attribute in your BuildingData script.

Rename the new BuildingData object to TurretData

Adding Properties to BuildingData

Open the BuildingData script
Add a string Name property
Add an int Cost property

Editing Properties in the Inspector

Similar to MonoBehaviours you can modify serialized properties in Unity's Inspector.

Select TurretData in your Project window
Set the Cost in the Inspector
Set the Name in the Inspector

Practice: Add a BuildingPrefab Property

Add a GameObject BuildingPrefab property to BuildingData
In the Inspector set BuildingPrefab to be your Turret Prefab

When you've finished, your TurretData should look similar to the image below:

Creating Multiple Instances

One of the benefits of a ScriptableObject is the ability to create multiple instances each with their own values.

In your Data folder:
Create a BuildingData for your GoldGenerator
Create a BuildingData for the building you defined at the beginning of this lesson

When you're done, your Data folder and objects should look similar to the video below:

Building Spawner

Your TurretSpawner has outgrown its original functionality. Its initial purposed was meant to spawn turrets. However, it is time to replace it with a BuildingSpawner that can be used to place anything defined as a BuildingData.

Rename TurretSpawner to BuildingSpawner

Select the TurretSpawner script
Rename the script to BuildingSpawner

Open the script
Update the class name to match the file name BuildingSpanwer

Update References in the Scene

Select your TurretSpawner from the Hierarchy
Rename it to BuildingSpawner
Verify that it has a Building Spawner component in the Inspector

Refactor `BuildingSpawner` to use BuildingData

Open the BuildingSpawner MonoBehaviour
Remove the TurretPrefab property
Add a BuildingData Selected

Update your Instatiate call to use the Selected.BuildingPrefab property
If necessary, update any other references to TurretPrefab to use Selected.BuildingPrefab

Update Buttons

In the Hierarchy select Turret Button
Update the OnClick listener to set Selected to TurretData
Enter Play Mode to test that you can place your Turret

Repeat this process for your other 2 buildings

When you have finished, your game should look and act similar to the video below:

Use `Selected.Cost`

In BuildingSpawner.SpawnTurret:
Update your code such that Controller.Gold is reduced by Selected.Cost when the building is placed.

Enter Play Mode and test that each building used the specified amount

Challenge: Fix BuildingSpawner

Currently, BuildingSpawner always displays 50 Gold - Place Turret even when placing non-turret buildings. Additionally, you can build structures that cost too much so long as you have at least 50 gold.

The Info Label should display the cost and name of Selected
The Info Label should display Not Enough Gold if the player does not have enough gold to build the selected building
Update CanSpawn to use Selected.Cost
Update your InfoLabel's starting text to be empty (or another message of your choice)