Category: coding

• [Dev Log] save system V0.1

  Got a pretty interesting surprise today when I started working on the project. For some reason my github is corrupted. I did some research and ended up removing and adding my origin back. Not sure why the head became null out of no where…but then after that I finally got to complete the first iteration of the high level game loop and move on to the save system.

  When you load the game, you need to have a few information:

  • name of the scene
  • player data
    • health, mana
    • current location
    • state
  • item data
    • With their specific information

  More is needed for saving:

  • save time
  • progress (ex. chapter 3 – 1)
  • name of the save

  The class that holds the information above should use attribute [System.Serializable] since we are using the JsonUtility in Unity. Using ToJson and FromJason can easily turn the class into text format. I choose to have a static member of save data to carry them across the scene. We have all the scene script derived from a base scene script. It will be nice if we can define the load function callback in the base script’s awake, and have the base call it. Unfortunately, Unity’s C# behave a little bit different and won’t do that. Seems like we will have to either have all the scene script do their own loading function in Awake or call it in Awake, or having the base class do it in its own Awake and make sure the child always call base.Awake() as the first line.

  Not all the scene needs to load data, so having each scene handles the data is probably what we are going to do…however, it will be nice if we can clean the save data after we are done loading. We could use an in-game MonoBehaviour to track it, but that means we need another actor/component in every scene. Something I want to try is a clean-up-after-yourself approach. When the save data got taken, it should clean it self after it. When all the data got cleaned, we know all the loading has happened and it can wipe itself after that. Right now it works without thinking about the loaded data, meaning it might have trouble when finishing a game and move into next level. The next step will be implementing that system.

  June 21, 2025

  coding, programming, Unity

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• Unity notes

  • Macro: nameof(functionName) returns a string, which is the same for just doing “functionName”, but it is safer.
    • It is safer because we can change our function name in future. If we are using a normal string, it will compile and lose the ability to know that it needs to change. On the other hand, nameof() method will fail as the parameter is no longer valid.
  • Often used specifiers:
    • For member:
      • [Header(“catagory”)]
      • [Min(value)]
      • [Max(value)]
      • [Space]
      • [SerializeField]
      • [Tooltip(“tool tip”)]
      • [HideInInspector]
    • For class:
      • [RequireComponent(typeof(class))]
      • [System.Serializable]
        • Make sure you have this if you want to have this class editable in Unity editor
    • For function:
      • [SettingsProvider]
  • To create a custom project setting, make a class from ScriptableObject with the target variable with [SerializeField]
    • In your class, create a const string with the path of the asset for you setting
    • Create functions to create/save setting
    • Create another class from SettingsProvider, with a SerializedObject as member
    • Override the OnGUI function and use EditorGUILayout.PropertyField and call FindProperty on your SerializedObject to make the property on the project setting UI, followed by ApplyModifiedPropertiesWithoutUndo
    • EditorGUILayout.PropertyField(CustomSettings.FindProperty(“SettingName”));
    • Create a function that returns your SettingsProvider and use [SettingsProvider] on the function
  • When you have C++ DLL for unity project, Unity won’t be able to recover from critical errors like how it handles it in C#
    • The crash log and dump will be stored at this location: C:\Users\<username>\AppData\Local\Temp\Unity\Editor\Crashes\
  • In the situation where there are static data for the scene and you are loading scene asynchronously. The game might have issue as the static data will be polluted.
    • The solution for this is create a buffer map, something like loading map to load between the 2 scenes. To make sure the new map will be loaded after the old map unloaded
  • OnValidate is called when member got modified in editor, and when entering play/editor mode against default value. The latter might need to be avoid
    • you can have a bool to mark if OnValidate is called or not
    • use EditorApplication.isPlaying and EditorApplication.isPlayingOrWillChangePlaymode to prevent the logic being called during play mode
  • LineRenderer can only do 1 line, but it can do a lot of nodes
    • When want to render more than 1 line, you can use multiple game object with LineRenderer component or have the 1 LineRenderer component render a long line like embroidery
  • When doing singleton, don’t do it in constructor (That is what you should do in C++, but not Unity)
    • Do it in Awake function

  June 20, 2025

  c, coding, programming, software, technology, Unity

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• Mysteries Errors

  • Cool, so there is a way to add date to blog post, but I need to add the component myself? Maybe there is a template or some sort…not like a block pattern that I still need , but actually automatic.
    • Ah, yes. As I type that, editing the post template just make sense and there is no reason to add date in title anymore.
  • Seems like C# in Unity also got the issue of “this is null”…I understand they are functions that can be static, but the language should know that. It will be nice when a function is being called on a variable that has yet to be initialized it will fail right there instead of inside whatever function it is calling. Pretty sure there are times it does handle it properly…
  • When making DLLs for your Unity project, including C++ solution into the C# solution won’t be needed. Seems like it used to be the right way but it no longer works. Just have the C++ solution generate the DLLs into the right location where C# solution can get.
  • Circular dependency in blueprint is still the devil for Unreal engine. Since it couldn’t detect it, it will just break some random, unrelated things. The best way to fix it is just walk through the changes and find out which one happened to be the one who completed the cycle.

  Unity Input Systems

  When making input systems, sometimes you ended up with a number of inputs are basically the same, but have to be implemented separately. For example: ctrl + num
  
  I was using the Unity Input Action System, and ended up having a huge number of input actions: ctrl + num, shift + num, alt + num, and even just the number key needs its own input. That is 40 of them with 4 different actions.

  It is going to be really annoying to go through all 40 of them and assign proper callbacks, not even saying the difference will just be the integer that got passed in…

  The right way to handle it with grace is get the property(variable) with name. Lucky Unity Input Action System allows us to do that with C#.

  Make your input action assets into code and you can access the input actions as below:

  [C#]
  m_myInput = new MyInput();
  
  for (int i = 0; i < 10; i++)
  {
      string index = i.ToString();
  
      string inputActionName = $"InputAction{index}";
  
      //MyInputActions means it is under Action Maps "MyInput"
      var inputActionProp = typeof(MyInput.MyInputActions).GetProperty(inputActionName);
  
      m_MyActions[i] = (InputAction)inputActionProp .GetValue(m_myInput.MyInput);
  
      //need to capture new variables for each lambda
      int capturedIndex = i;
      m_MyActions[i].performed    += ctx => MyCallBack(capturedIndex);
      
  }

  Not satisfied with that code block up there, but it will do for now.

  June 6, 2025

  coding, programming, Unity, Unreal

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