using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class HUDFPS : MonoBehaviour
{

    public  float updateInterval = 0.5F;

    private float accum   = 0; // FPS accumulated over the interval
    private int   frames  = 0; // Frames drawn over the interval
    private float timeleft; // Left time for current interval

    void Start()
    {
        if ( !GetComponent<Text>() )
        {
            Debug.Log("UtilityFramesPerSecond needs a Text component!");
            enabled = false;
            return;
        }
        timeleft = updateInterval;
    }

    void Update()
    {
        timeleft -= Time.deltaTime;
        accum += Time.timeScale / Time.deltaTime;
        ++frames;

        // Interval ended - update GUI text and start new interval
        if ( timeleft <= 0.0 )
        {
            // display two fractional digits (f2 format)
            float fps = accum / frames;
            string format = System.String.Format("{0:F2} FPS", fps);
            GetComponent<Text>().text = format;

            if (fps >= 30)
            {
                GetComponent<Text>().color = Color.green;
            }
            else if (fps > 15)
            {
                GetComponent<Text>().color = Color.yellow;
            }
            else
            {                
                GetComponent<Text>().color = Color.red;
            }



            timeleft = updateInterval;
            accum = 0.0F;
            frames = 0;
        }
    }
}