using UnityEngine;
using UnityEngine.UI;

// Display FPS on a Unity UGUI Text Panel
// To use: Drag onto a game object with Text component
//         Press 'F' key to toggle show/hide
public class TextFPSCounter : MonoBehaviour 
{
    public Text text;
	public bool show;

	private const int targetFPS = 
		#if UNITY_ANDROID // GEARVR
		60;
		#else
		75;
		#endif
	private const float updateInterval = 0.5f;

	private int framesCount; 
	private float framesTime; 

	void Start()
	{
        //only test
#if false
        QualitySettings.vSyncCount = 0;
#if UNITY_EDITOR
        Application.targetFrameRate = 1000;
#endif
#endif

        // no text object set? see if our gameobject has one to use
        if (text == null) 
		{ 
			text = GetComponent<Text>(); 
		}
	}
	
	void Update()
	{
		if (Input.GetKeyDown(KeyCode.F))
		{
			show = !show;
		}

		// monitoring frame counter and the total time
		framesCount++;
		framesTime += Time.unscaledDeltaTime; 

		// measuring interval ended, so calculate FPS and display on Text
		if (framesTime > updateInterval)
		{
			if (text != null)
			{
				if (show)
				{
					float fps = framesCount/framesTime;
					text.text = System.String.Format("{0:F2} FPS", fps);
					text.color = (fps > (targetFPS-5) ? Color.green :
					             (fps > (targetFPS-30) ?  Color.yellow : 
					              Color.red));
				}
				else
				{
					text.text = "";
				}
			}
			// reset for the next interval to measure
			framesCount = 0;
			framesTime = 0;
		}
		
	}
}