using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ColorInterpolation : MonoBehaviour
{
    public Color startColor;
    public Color endColor;

    private void OnGUI()
    {
        if (GUILayout.Button("Over 5 seconds"))
            //interpolate from A to B in 5 seconds
            StartCoroutine(TransitionOverDuration(5));

        if (GUILayout.Button("Half spectrum per second"))
            //interpolate from white to black in 2 seconds
            StartCoroutine(TransitionOverDuration(0.5f));
    }

    IEnumerator TransitionOverDuration(float duration)
    {
        float startTime = Time.time;
        float endTime = startTime + duration;

        Color c = startColor;
        while(Time.time < endTime)
        {
            //remap Time.time to 0-->1 range (or p for percentage completion)
            float p = Mathf.InverseLerp(startTime, endTime, Time.time);
            c = Color.Lerp(startColor, endColor, p);

            Debug.Log($"<color=#{ColorUtility.ToHtmlStringRGBA(c)}>Color!</color> {Time.time.ToString("f2")}");
            yield return null;
        }
    }


    IEnumerator TransitionBySpeed(float speed)
    {

        Color c = startColor;

        while (c != endColor)
        {
            //cool usage of Vector4! For what is a color if not but 4 floats!?
            c = Vector4.MoveTowards(c, endColor, speed * Time.deltaTime);

            Debug.Log($"<color=#{ColorUtility.ToHtmlStringRGBA(c)}>Color!</color> {Time.time.ToString("f2")}");
            yield return null;
        }
    }
}