Unity C#: Typewriter Text Effect (letter-by-letter) [with comments]

using UnityEngine; using UnityEngine.UI; using System.Collections; public class talkScript : MonoBehaviour {//For NPC, but can be changed to be used anywhere public string[] message; //String array containing the message. Each unit of the array is a dialogue. Keep it short. private string messageString; //Will contain the string being printed private int lineAt = 0; //At which line (unit) are we at currently, in the message[] array? private float charAt = 0; //At which character are we at currently, in our messageString? public bool talking, canTurn; //booleans, if the npc is talking AND if he can turn to face the player public Text txt; //The GUI text element which is placed in the Canvas in the Unity editor where the message will be displayed public float talkingSpeed; //The speed at which characters are displayed public GameObject messageBox, player, touch; //the messageBox GUI element (may be a sprite), the player(player must have a <talking> variable (boolean) too!), and the GUI sprite indicating that the line has been spoken and the player can click to continue // Use this for initialization void Start () { } // Update is called once per frame void Update () { //Happens every frame if (talking==true){ //if talking if (canTurn) transform.LookAt (new Vector3(player.transform.position.x, transform.position.y, player.transform.position.z)); //if it can turn, it'll turn around to look at the player txt.text = messageString; //sets the GUI text element's text to our messageString if (charAt < message[lineAt].Length){ //if the line hasn't been completed yet touch.SetActive (false); //disable the touch (continue) GUI sprite charAt += talkingSpeed/10; //increase characters displayed at the speed specified messageString = message[lineAt].Substring(0, Mathf.Clamp (Mathf.RoundToInt(charAt), 0, message[lineAt].Length)); //calculate how many characters will be displayed and assign to messageString } //else if it isn't talking else{ touch.SetActive (true); //enable the continue GUI sprite if (Input.GetMouseButtonDown(0)){ //if clicked, proceed this way: if (lineAt == message.Length - 1){ //if there is no line left to speak (in the message[] array) player.GetComponent<playerScript>().talking = false; //sets players talking variable to false talking = false; //not talking now messageBox.SetActive (false); //disable messageBox GUI sprite }else{ //if there IS/ARE line(s) to speak (in message[] array) messageString = ""; //reset messageString lineAt++; //increase line number charAt = 0; //reset charAt } } } } } void OnMouseDown () { //When mouse is clicked if (Vector3.Distance (transform.position, player.transform.position) < 4 && !talking && player.GetComponent<playerScript>().talking==false){ //if the player is close enough and both objects' talking variables are false lineAt = 0; charAt = 0; //reset these variables player.transform.LookAt(new Vector3(transform.position.x, player.transform.position.y, transform.position.z)); //make the player look at the NPC player.GetComponent<playerScript>().talking = true; //set player's talking variable to true talking = true; //is talking messageBox.SetActive(true); //enable messageBox GUI sprite messageString = ""; //reset messageString } } }