Bungeon

Save and Load System

The system will save player's status and inventories, including:

• how many days has passed

• how many collectables the player hold

Also, the system will reload every puzzle that player has worked out. In this game, puzzles are solved by moving crates onto correct places to create new route or push putton. The whole mechanism is physics-driven, i.e. the door will shut if the crate is moved from the button location. The saving system reads all crates' world position and save them in file. Upon reading, the crates will be placed to correct locations. The number of movable crates in game is fixed and strictly one-on-one mapping.

Implementation

public void SaveGame()

    {

        Dictionary<string, string> m_dataToSave = gameData.WriteToDict();

        // false means the file will be overwritten.

        // public StreamWriter(string path, bool append, Encoding encoding);

        StreamWriter sw = new StreamWriter(savePath, false, Encoding.ASCII);

        foreach (KeyValuePair<string, string> kvp in m_dataToSave)

        {

            sw.WriteLine(kvp.Key + "=" + kvp.Value);

        }

        foreach (GameObject button in m_buttonOBJS)

        {

            bool isButtonPressed = button.GetComponent<PuzzleButton>().IsPressed;

            if (isButtonPressed)

            {

                //m_doorsOpened.Add(button);

                // only write pressed button's position

                sw.WriteLine("buttonPressed=" + button.transform.position.x + "," + button.transform.position.y + "," + button.transform.position.z);

            }

        }

        foreach (GameObject checkCrate in m_crateOBJS)

        {

            // write to file

            // note: it offsets crate's location to make sure it won't stuck at ground

            // could be removed if this is deemed unnecessary.

            sw.WriteLine("crate=" + checkCrate.transform.position.x + "," + (checkCrate.transform.position.y + 2.0f) + "," + checkCrate.transform.position.z);

        }

        sw.Close();

        Debug.Log("Game Saved.");

    }

    public void ReadFromSave()

    {

        // TODO: add execption handlers in this function

        Dictionary<string, string> m_inputStatus = new Dictionary<string, string>();

        List<Vector3> m_crateRespawnLocation = new List<Vector3>();

        List<float> m_buttonDistance = new List<float>();

        foreach (string line in File.ReadLines(savePath))

        {

            if (line[0] == ';')

            {

                // allow comments starting with semicolon.

                // note: comments won't be written back to save files

                continue;

            }

            string[] fields = line.Split("=");

            if (fields[0] == "crate")

            {

                // read crate location

                string[] position = fields[1].Split(",");

                Vector3 crateLocation = new Vector3(float.Parse(position[0]), float.Parse(position[1]), float.Parse(position[2]));

                m_crateRespawnLocation.Add(crateLocation);

            }

            else

            {

                if (fields[0] == "buttonPressed")

                {

                    // restore button

                    string[] position = fields[1].Split(",");

                    Vector3 buttonLocation = new Vector3(float.Parse(position[0]), float.Parse(position[1]), float.Parse(position[2]));

                    m_buttonDistance.Clear();

                    foreach (GameObject button in m_buttonOBJS)

                    {

                        m_buttonDistance.Add((button.transform.position - buttonLocation).magnitude);

                    }

                    int minIndex = m_buttonDistance.IndexOf(m_buttonDistance.Min());

                    PuzzleButton p_button = m_buttonOBJS[minIndex].GetComponent<PuzzleButton>();

                    p_button.IsPressed = true;

                    StartCoroutine(p_button.SquishButton());

                }

                else

                {

                    m_inputStatus[fields[0]] = fields[1]; // read it and cover default value

                }

            }

        }

        // reset crate location

        // make sure no illegal access

        int noOfCrates = Mathf.Min(m_crateRespawnLocation.Count, m_crateOBJS.Count);

        for (int i = 0; i < noOfCrates; i++)

        {

            m_crateOBJS[i].transform.position = m_crateRespawnLocation[i];

        }

        gameData.ParseFromDict(m_inputStatus);

    }

Discussion

• Binary optimization can be used on save files; we don't have to read/write human-readable floating-point numbers and strings, and only binary representations will suffice. However, we did not implement this feature for debugging purposes since the I/O around save files are NOT intensive.

• One of our teammates dropped out of school during this project, which left the UI part very bug-prone. We have to introduce a lot of extra checkings to make sure the save files are loaded when we want and deleted when we asked.

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