RT - Simple coroutine tweens

RT.cs

using System;
using System.Collections;
using UnityEngine;

public static class RT
{
	static public IEnumerator Tween(float duration, Action<float> task, Func<float,float> easeFunc = null, float delay = 0)
	{
		while(delay > 0) 
		{
			delay -= Time.deltaTime;
			yield return null;
		}

		if(duration <= 0) 
		{
			task(1f);
		}
		else 
		{
			float t = -delay; //at this point delay can only be zero or negative. if negative it means we overshot it a bit, so start the tween using that amount
			while(t < 1f)
			{
				t = t+Time.deltaTime/duration;
				if(t > 1f) t = 1f;
				if(easeFunc == null) task(t); else task(easeFunc(t));
				yield return null;
			}
		}
	}

	static public IEnumerator AddCallback(IEnumerator routine, Action callback)
	{
		while(routine.MoveNext()) yield return routine.Current;
		callback();
	}

	//keep doing task every frame until it returns false
	static public IEnumerator Do(Func<bool> task)
	{
		while(task()) yield return null;
	}
}