QualityLevelControl

/*

This script provides runtime control over the application's quality level with FPS monitoring and UI feedback.

Keyboard button controls:
O - Decrease Level
P - Increase Level

For monitoring, drag and drop UI text objects to the following variables of the script inspector: 
- QualityTxt : shows the current quality level = "VeryLow", "Low", "Medium", "High", "VeryHigh", "Ultra"
- FpsTxt : displays frame rate

--------------------------------------------
 Author: Ahmed jerbi
 Date: September, 2020
 www.github.com/Ahmed-jerbi
--------------------------------------------
*/

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

public class QualityLevelControl : MonoBehaviour
{
 
    public Text QualityTxt;
    public Text FpsTxt;
    string[] QLevels = { "VeryLow", "Low", "Medium", "High", "VeryHigh", "Ultra" };
    int i=5;
    float deltaTime;
    void Start()
    {
    // UI init
        QualityTxt.text = " Quality level : " + QLevels[i];

    }

    void Update()
    {
        //Calculate and Display FPS
        deltaTime += (Time.deltaTime - deltaTime) * 0.1f;
        float fps = 1.0f / deltaTime;
        FpsTxt.text = Mathf.Ceil(fps).ToString();

        //switch quality level at runtime on button inputs, then update the UI 
        if (Input.GetKeyDown(KeyCode.O))
        {   if (i>0)
            {
                QualitySettings.DecreaseLevel();
                i--;
                QualityTxt.text = " Quality level : " + QLevels[i];
            }

        }

        if (Input.GetKeyDown(KeyCode.P))
        {
            if (i< 5)
            {
                QualitySettings.IncreaseLevel();
                i++;
                QualityTxt.text = " Quality level : " + QLevels[i];
            }
        }
    }
}