A few days ago I started a new project, a MOBA like test, and it is been going well for the most part. Currently I am having difficulties importing slowness effect or buff/debuff system in to the game. The exact problem is with the timer I need to change the speed value of the character but I can not use ref/out parameters in coroutines. I tried some other things like using invoke or using functions but they just do not do what I want. All feedback is appreciated and thanks in advance
Here is the code:

Coroutine:

public IEnumerator ApplyDebuff(ref float stat, float percentage, float duration)
{
    float originalValue = stat;
    float timeStamp = Time.time;

    while (Time.time < timeStamp   duration)
    {
        float debuffValue = percentage / 100 * originalValue;
        stat -= debuffValue;

        yield return null;
    }
    stat = originalValue;
}

Where I call the coroutine

private void CheckForCollision()
{
    Collider[] colliders = Physics.OverlapSphere(position, scale, layerMask);

    foreach(Collider c in colliders)
    {
        c.TryGetComponent<PlayerController>(out PlayerController player);
        player.ApplyDebuff(ref player.speed, 70, 5);
        player.TakeDamage(50);

        Destroy(gameObject);
    }
}

CodePudding user response：

You can't use ref in IEnumerator, the Action<float> solves the problem. This method is called Callback.

public IEnumerator ApplyDebuff(float stat, float percentage, float duration, Action<float> OnWhileAction, Action<float> AfterWaitAction)
{
    float originalValue = stat;
    float timeStamp = Time.time;

    while (Time.time < timeStamp   duration)
    {
        float debufValue = percentage / 100 * originalValue;

        OnWhileAction(debufValue);
        
        yield return null;
    }
    AfterWaitAction(originalValue);
}

The following lambda can execute your command after wait simply.

foreach(Collider c in colliders)
{
    /// ...
    player.ApplyDebuff(player.speed, 70, 5, debufValue => player.speed-=debufValue,  orginalValue => player.speed = orginalValue);
    ///...
}

For using System library as write using system in top of code;