A little help about how to save and load a game, please.

AndWolfDev

Hey, folks!

Well, I'm pretty much new to game development and programming, so I need some help with my code for saving. I'm studying the documentation and trying to use their example code as a base, but the singleton and saving game documentation aren't exactly simple for me. Well: 1. Can I put save game and load game features in separated scripts? My guess is positive, so how? 2. Can I save the entire scene instead of specific values like life bars, inventory, storage? 3. How exactly autosave works in code?

Thanks!

fire7side

This is kind of helpful for save/load: https://kidscancode.org/godot_recipes/basics/file_io/

For starters, it's a lot better to save values from a game. Autosave is just using a timer and saving every so often.

If you want to look at saving scenes there is a tutorial here:

TwistedTwigleg

This page on saving games from the documentation may also be helpful as a reference.

AndWolfDev

Thanks, I'll look into it! But the documentation itself didn't help me that much, although I'm always looking into it whenever I need to learn something.

cybereality

The save load script can (and should be) and Autoload, which means you can access it from anywhere. The save and load functions should be in that same script, and any other script can send/retrieve data from it. You can save the entire scene, but it's not a good idea (too much data). Better to make which objects are "savable" and have them send their relevant data to the save script (this is called serialization). Autosave just calls the save function at predetermined points, like if a player has walked over a trigger area.

Erich_L

Can I save the entire scene instead of specific values like life bars, inventory, storage?

When I was looking into this I too was looking for a really easy fix; I just wanted godot to save my entire scene so I didn't have to put much thought into it. Someone please correct me if I'm wrong, but there's no easy fix to saving and loading; you're going to have to put a little time into it. You'll need to decide what should be saved how / when it should be loaded. I ended up using the put n dictionaries in a resource file and save that method. IMO it works great and I have control over how big that save file gets.

cybereality

Yes, saving the entire game would be crazy. Big file size and probably slow to load. You only want to save exactly what you need, and in an easy to parse text file.

AndWolfDev

Thanks for all the help, guys. When I succeed, I will come to show how I made it.

AndWolfDev

@cybereality said: The save load script can (and should be) and Autoload, which means you can access it from anywhere. The save and load functions should be in that same script, and any other script can send/retrieve data from it. You can save the entire scene, but it's not a good idea (too much data). Better to make which objects are "savable" and have them send their relevant data to the save script (this is called serialization). Autosave just calls the save function at predetermined points, like if a player has walked over a trigger area.

I need little more explanation about the files. I have a Start Scene and a Game Scene. I see no point in code the load function in the Game Scene, since I have to activate the load func in th Start Scene. Could you explain a little more, please? Should I code it in the Game Scene script and just call it from the Start Scene?

AndWolfDev

And I sincerely didn't understand a word of the last phrases of the load_func in the documentation. Could anyone explain how do I make these codes fits when I have to save just numbers and values?

 # Load the file line by line and process that dictionary to restore
    # the object it represents.
    save_game.open("user://savegame.save", File.READ)
    while save_game.get_position() < save_game.get_len():
        # Get the saved dictionary from the next line in the save file
        var node_data = parse_json(save_game.get_line())
        
        # Firstly, we need to create the object and add it to the tree and set its position.
        var new_object = load(node_data["filename"]).instance()
        get_node(node_data["parent"]).add_child(new_object)
        new_object.position = Vector2(node_data["pos_x"], node_data["pos_y"])
        
        # Now we set the remaining variables.
        for i in node_data.keys():
            if i == "filename" or i == "parent" or i == "pos_x" or i == "pos_y":
                continue
            new_object.set(i, node_data[i])

cybereality

The point of having the save script in an autoload is that it is available everywhere globally in the game. For a single screen/scene type of game, this is not needed. But many games have different levels, and you want to be able to save at every level and not duplicate code. It's also a good design and good practice, so it's no harm even if your whole game is one level.

cybereality

If you just need to save a few simple values, you don't have to do the full serialization. This tutorial shows how to save just a couple values easily. https://kidscancode.org/godot_recipes/basics/file_io/

AndWolfDev

I'm taking a while to respond but I'm still into it. This kids can code docs seem much more into what I'm needing right now. But I still need to save around 10 values or more. How can I adapt that code into a dictionary or using the group Persist like godot docs are suggesting?

cybereality

I think store var can save Dictionaries.

AndWolfDev

Thanks, I'll try that method. Should I create the dictionary right before the save/load funcs or a create it together with the variables up there?

Thank you for the help so far!

cybereality

You can create it at any time, but it probably makes sense to do it directly before saving so it has the most updated data.