Adventures in Unity – 1.7c Highscores (In-Game Backend)

Once the server side code was in place, I needed methods to download the current high score list and upload new entries in-game.

The basic code for connecting to the server and retrieving scores was provided by the unify community ‘Server Side Highscores’ article.

I added the method Md5Sum (also provided by the unify community) to encode the data before sending to the server.

Expanding on this code using the  YouTube tutorial ‘[Unity Tutorial] Online Highscores 01 (dreamlo)‘ – Using IEnumerator when adding a new highscore or downloading the current highscore list provides a smoother in game experience for the player, since it allows the primary thread to manage the game, while the secondary threads manage the highscore table status.

 

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The modified code was placed in a c# script called HighScoreController – Which I attached to an empty component also called HighScoreController.

Functionality within the HighScoreController script can be split into two fairly clear sections;

1. Add New High Score.
2. Download (format and store) current highscores list.

 

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1. Add New High Score;

Adapting the method to add new highscores – Using IEnumerator to allow the code to run on a separate thread to the main game;

    
public static void AddNewHighScore(string userName, int score)
{
     instance.StartCoroutine(instance.UploadNewHighscore(userName, score));
}

// remember to use StartCoroutine when calling this function!
IEnumerator UploadNewHighscore(string name, int score)
{
     //This connects to a server side php script that will add the name and score to a MySQL DB.
     // Supply it with a string representing the players name and the players score.
     string hash = Md5Sum(name + score + secretKey);

     string post_url = addScoreURL + "name=" + WWW.EscapeURL(name) + "&score=" + score + "&hash=" + hash;

     // Post the URL to the site and create a download object to get the result.
     WWW hs_post = new WWW(post_url);
     yield return hs_post; // Wait until the download is done

     if (hs_post.error != null)
     {
          print("There was an error posting the high score: " + hs_post.error);
     }

     else
     {
          DownloadHighscores();
     }

}

With an associated method which encrypts highscores for sending (also provided by the Unify Community site);

    
public string Md5Sum(string strToEncrypt)
{

     System.Text.UTF8Encoding ue = new System.Text.UTF8Encoding();
     byte[] bytes = ue.GetBytes(strToEncrypt);

     // encrypt bytes
     System.Security.Cryptography.MD5CryptoServiceProvider md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
     byte[] hashBytes = md5.ComputeHash(bytes);

     // Convert the encrypted bytes back to a string (base 16)
     string hashString = "";

     for (int i = 0; i < hashBytes.Length; i++)
     {
          hashString += System.Convert.ToString(hashBytes[i], 16).PadLeft(2, '0');
     }

     return hashString.PadLeft(32, '0');

}

 

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2. Download (format and store) current highscores list;

Expanding on the Unify Community method to download highscores as a string from the server. As with the AddNewHighScore method, DownloadHighScores is also modified from the Unify Community code using IEnuerator to allow threaded functionality;

public void DownloadHighscores()
{
     StartCoroutine("DownloadHighscoresFromDatabase");
}

// Get the scores from the MySQL DB to display in a Text.
// remember to use StartCoroutine when calling this function!
IEnumerator DownloadHighscoresFromDatabase()
{

     WWW hs_get = new WWW(highscoreURL);
     yield return hs_get;

     int counter = 0;
     for (; counter < hs_get.text.Length; counter++)
          if (hs_get.text[counter] == '#')
               break;

     string hs_got = hs_get.text.Substring(0, counter); //Substring(0, counter);

     if (hs_get.error != null)
     {
          print("There was an error getting the high score: " + hs_get.error);
     }
     else
     {
          FormatHighScores(hs_got);
          highScoreDisplay.OnHighScoresDownloaded(highScoresList);
     }

}

 

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Note: The highscore data is returned by 000webhost as a text string – When returning the data, 000webhost  appends a little extra/unwanted info

http://stats.hosting24.com/count.php

This code is used by 000webhost to check site usage – Which is fair enough, since they provide the hosting for free – But is unneeded and unwanted by the game – I definitely dont want it getting mixed up with the highscore table.

My quick and dirty fix to this;

  
int counter = 0;

for (; counter < hs_get.text.Length; counter++)
     if (hs_get.text[counter] == '#')
          break;

string hs_got = hs_get.text.Substring(0, counter); //Substring(0, counter);

On the server, after creating the highscore list, I append a ‘#’ to the end of the string. A character I know isn’t used either in the highscores (it cant be entered when adding a highscore) or in 000webhost’s appended text. I loop through the highscore text, searching for the position of the hash character – Once found, the code removes it and any text which follows.

 

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After DownloadHighscoresFromDatabase has retrieved the highscore text; it calls FormatHighScores which parses the names and scores from the text and stores them for use in game;

void FormatHighScores(string TextStream)
{
     string[] entries = TextStream.Split(new char[] { '\n' }, System.StringSplitOptions.RemoveEmptyEntries);
     highScoresList = new HighScore[entries.Length];

     for (int counter = 0; counter < entries.Length; counter++)
     {

          string[] entryInfo = entries[counter].Split(new char[] { '|' });

          if (entryInfo.Length == 2)
          {

               //---

               string userName = entryInfo[0];
               int score = int.Parse(entryInfo[1]);
               highScoresList[counter] = new HighScore(userName, score);

               //---

          }

     }

     //---

}

FormatHighScores populates a list of HighScore struct. This is used by the HighscoreDisplay script to populate the highscore table – And by the HighScoreAdd script to check if the new score should be counted as a new entry;

public struct HighScore
{
     public string userName;
     public int score;

     public HighScore(string inUserName, int inScore)
     {
          userName = inUserName;
          score = inScore;
     }
}

 

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This provides a backbone in-game to manage highscores – But I still need methods to display current high score & add new highscores.

 

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Play the game (WebGL)

Grab a copy of the project here

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