Recharge delay on shield regen through coroutines

Questions & Answers
1

I’m trying to implement a recharge delay for my energy shield class using coroutines. The idea is to reset duration of the delay each time damage is received. I’ve got this code so far:

public class ShieldStats : MonoBehaviour {
    public float currentShield = 0;
    public float maxShield = 100f;
    public float rechargeRate = 0f;
    public float rechargeDelay = 0f;
	public float rechargeDelay = 0f;
	private bool shieldRechargeAllowed = true;

	void Start () {
		InvokeRepeating ("RechargeShield", 1, 0.1f);
	}

	public float ApplyDamage (float damage) {
		StartCoroutine (DisallowShieldRegenForXSeconds (rechargeDelay));
	        ......
	}

	public void RechargeShield () {
		if (shieldRechargeAllowed && currentShield < maxShield) {
			currentShield += rechargeRate;
			if (currentShield > maxShield)
				currentShield = maxShield;
			}
	}

	void OnDisable () {
		CancelInvoke ("RechargeShield");
	}

	IEnumerator DisallowShieldRegenForXSeconds (float rechargeDelay) {
		shieldRechargeAllowed = false;
		yield return new WaitForSeconds (rechargeDelay);
		shieldRechargeAllowed = true;
	} 
}

Thing is, each time damage applied - new coroutine is instantiated. When the damage is received after old coroutine yield’s it creates new coroutine which sets flag to false, but when old coroutine starts again - it sets bool to true, where it should be false.

Is there a way to stop previous coroutine instances and keep only latest one called? Or should I use deltatime for this purposes?

2

You can use StopAllCoroutines() to stop all executing coroutines before starting a new one. That way you can ensure that there is only one instance of a specified coroutine at a given time.
Take a look at StopAllCoroutines and StopCoroutine

3

maybe a crude fix but you can run a timer like this>

float rechargeCooldown = 0f;

void Update () {
    rechargeCooldown = Mathf.Max(rechargeCooldown - Time.deltaTime, 0f);  
}

public float ApplyDamage (float damage) {
    rechargeCooldown = rechargeDelay;
}

public void RechargeShield () {
    if (rechargeCooldown == 0f && currentShield < maxShield) {