unity-csharp

name	unity-csharp
description	Unity C# development — MonoBehaviour lifecycle, DOTS/ECS, URP/HDRP, ScriptableObjects, and Unity best practices
allowed-tools	["Read","Write","Bash","Grep"]
effort	high

When to activate

• Building games or tools with Unity Engine
• Writing performant C# scripts with Unity API patterns
• Using DOTS/ECS for high-performance entity systems
• Working with URP/HDRP shader graphs and render pipelines
• Implementing Unity addressables and asset management

When NOT to use

• For Unreal Engine development (use unreal-cpp)
• For Godot development (use godot-gdscript)
• For non-game Unity tooling

Instructions

1. Lifecycle awareness. Awake (once) → OnEnable (each activation) → Start (first frame) → Update (every frame) → OnDisable → OnDestroy.
2. Performance. Object pooling for frequent instantiate/destroy. Avoid GetComponent in Update (cache in Start). Use CompareTag not ==.
3. Data-driven design. ScriptableObjects for config data. JSON/YAML for level data. Addressables for async asset loading.
4. DOTS/ECS. Use for systems with 1000+ entities. Burst compiler for native performance. Jobs system for parallel work.
5. Input System. New Input System (package) over legacy. Action-based input. Support gamepad, keyboard, touch simultaneously.
6. Testing. Unity Test Framework (NUnit). Play mode tests for gameplay logic. Edit mode tests for editor tools.
7. Build optimization. IL2CPP for production. Strip engine code. Minimize shader variants. Profile with Unity Profiler.

Example

// ScriptableObject-driven weapon config
[CreateAssetMenu(menuName = "Weapons/Weapon Config")]
public class WeaponConfig : ScriptableObject {
    public float damage = 10f;
    public float fireRate = 0.2f;
    public float range = 50f;
    public AudioClip fireSound;
    public GameObject muzzleFlashPrefab;
}

public class WeaponController : MonoBehaviour {
    [SerializeField] private WeaponConfig config;
    private float nextFireTime;
    
    void Update() {
        if (Input.GetButton("Fire") && Time.time >= nextFireTime) {
            Fire();
            nextFireTime = Time.time + config.fireRate;
        }
    }
}