public static IEnumerator ExpoFade(Image target, float start, float end, float animationTime)
{
float elapsedTime = 0;
Color c = Color.white;
while (elapsedTime < animationTime)
{
c.a = PennerAnimation.ExpoEaseIn(
elapsedTime,
start,
end - start,
animationTime
);
target.color = c;
elapsedTime += Time.deltaTime;
yield return(0);
}
c.a = end;
target.color = c;
}