1. How to structure your code

Avoid the need to do domain reloading

How much speed is there to gain

• Unity 2021.3.9f1
• Almost empty project

5.5sec vs 0.1sec

How to make it work

• Avoid static fields
• Watch out for registering / unregistering handlers

public class StaticCounterExampleFixed : MonoBehaviour {
	static int counter = 0;

    [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
    static void Init() {
        counter = 0;   
    }
}

var isInFastMode = EditorSettings
	.enterPlayModeOptionsEnabled;
    
if (isInFastMode) {        
    if (GUILayout.Button(new GUIContent("SPEED"), _ButtonStylesEnabled)) {
        EditorSettings.enterPlayModeOptionsEnabled 
        	= false;
        EditorSettings.enterPlayModeOptions 
        	= EnterPlayModeOptions.None;
    }    
}
else {
    if (GUILayout.Button(new GUIContent("SPEED"), _ButtonStylesDisabled)) {
        EditorSettings.enterPlayModeOptionsEnabled 
        	= true;
        EditorSettings.enterPlayModeOptions 
        	= EnterPlayModeOptions.DisableDomainReload;
    }    
}

1. How to structure your code

Spearate your model from the view

Benefits of View-Model separation

• You'll ensure system separation
• Encourages writing functional code with clean data flow
• You'll be able to write edit mode tests

Tests

• No need to have them from the start
• No need to have 100% code coverage
• Very usefull as a documentation
• Actually speeds up new feature development as project grows

Data Flow

1. How to structure your code

Encapsulate systems

Goal: running pieces of the game independently

Tools to achieve encapsulation

• Use message queues instead of referencing
• Pass data through model
• Inject needed dependencies

  ... more on that later

2. How to store your data

Keeping data in Scriptable Objects

Seems like a great idea...

• Easy to start
• Changes update live
• Really powerfull with Odin:
• [Inline Editor]
• SO variables

No need for [CreateAssetMenu]

Pitfalls

Editor Performance

Pitfalls

Saving

Pitfalls

Changing SO structure

3. Which libraries and frameworks to use

Beyond Zenject

public class Foo : MonoBehaviour {
    ISomeService _Service;

    public void Init(ISomeService service) {
    	_Service = service;
    }

    public void DoSomething() {
        _Service.PerformTask();
    }
}

...

foo.Init(new Service());

public class TestInstaller : MonoInstaller {
	public override void InstallBindings() {
		Container
			.Bind<ISomeService>().FromInstance(new Service());
	}
}

public class Foo : MonoBehaviour {
	[Inject]
	ISomeService _Service;

	public void DoSomething() {
		_Service.PerformTask();
	}
}

public class Context : ScriptableObject {
    
	public ISomeService Service => _Service ??= new Service();

	private ISomeService _Service;

}

public class Foo : MonoBehaviour {
	[SerializeField]
	Context _Context;

	public void DoSomething() {
		_Context.Service.PerformTask();
	}
}

public class Foo : MonoBehaviour {   
	Context Context => 
		_Context ??= Resources.Load<Context>("context");

	Context _Context;

	public void DoSomething() {
		Context.Service.PerformTask();
	}
}

How to initialise MonoBehaviuors

• Before any game code starts
• Guaranteed to run everytime

[InitializeOnLoadAttribute]
public static class BootLoader {
	static BootLoader() {
		EditorApplication.playModeStateChanged += (nState) => {
			if (nState != PlayModeStateChange.ExitingEditMode)
				return;

			EditorPrefs.SetString(
				KEY_RETURN_TO_SCENE, 
				EditorSceneManager.GetActiveScene().name);

			var bootScene = AssetDatabase
				.LoadAssetAtPath<SceneAsset>($"Boot.unity");

			EditorSceneManager.playModeStartScene = bootScene;
		};
	}
}
							

						private void Load() {
						    var returnScene = EditorPrefs
						    	.GetString(KEY_RETURN_TO_SCENE, null);
						    EditorPrefs.SetString(KEY_RETURN_TO_SCENE, null);

						    if (returnScene != null) {
						        EditorSceneManager.LoadScene(
						        	returnScene, 
						        	LoadSceneMode.Additive);
						    }
						}							
						

What are the benefits

• Can run from any scene
• Easier DI to use
• Can run prefabs in separation

4. How to structure project

Avoid nested prefabs

Problems with nested prefabs

• Can never be sure change propagates
• Weird behaviour with overwritten properties
• Requires great discipline
• Sometimes flat out breaks

What instead

• Keep flat prefab structure
• Break prefab instances when making changes
• Prefer instantiating prefabs
• Avoid loading prefabs with scenes

4. How to structure project

Watch out for resource hog

Every referenced prefab is loaded

Addressables

• Not as hard as you think
• Quite more stable than you anticipate
• Easy way to add "soft" references
• No need for creating bundles -can still load from resources