Implement game saves

[miskatonicstudio]

Has to store:

• list of inventory item
• current state of items (e.g. on which page a book is open)

If a list is loaded from a save file into the game, the signals have to be blocked (in case e.g. "add_book_to_inventory" has a corresponding audio, it cannot be played).

EDIT: In general, there seem to be 2 approaches:

• save selected information and use it to recreate the state of the game
• save the entire current scene and load it later

The first approach would probably work best if all the important information is stored globally (in singletons). That includes all Player info (there is no singleton for that yet), as well as e.g. info about activation of interactive objects/screens etc. (to remove already activated interactive objects). The existing API of singletons can probably be kept, with saves extracting and storing the information from them.

Depending on the chosen solution, 3 options could be required: save, load, and reset (for creating a new game).

[sergicollado]

It would be nice if Goat get save game checkpoints functionality.

[miskatonicstudio]

@sergicollado thank you for the suggestion. GOAT is primarily aimed at adventure games, where checkpoints are usually not used, but maybe this could work for some more experimental storytelling, so I've created a new task for that ;)

[miskatonicstudio]

This is a bit more difficult than expected. Saving data manually doesn't seem to be an option, loading the entire scene doesn't seem to work. More details are described here:

https://godotengine.org/qa/69338/how-to-properly-load-a-saved-scene-skipping-_ready-method

Some solutions (if the question above will not receive an answer):

• save and load the state manually, dealing with the fact that it will take a lot of work (e.g. log information about already activated interactive items) and some information will be lost (e.g. animation state)
• split the game into chapters and only load the entire chapter (a lot of progress can be easily lost if someone interrupts a chapter)
• split the game into scenes, switch between them (each time run a _ready method), only save the current scene, the initial position on the scene, and the global state (e.g. inventory items)

EDIT: if the game switches between scenes, then saving the state manually will have to be implemented anyway. However, a simple game doesn't have to switch between scenes (can hide/show them when necessary).

[sergicollado]

I think the simple it's the better, I usually save a json with some parameters:

• Current scene to load, player position ( or a default place to spawn player), current objects in the inventary ,and so on ... in this case maybe is interesting save also info about objects already actived or a kind of npc status if it needs. Then, from the main script that control the level you can initialize all objects, inventary, doors unlock ... It's the same that a settings file but with the status of the game.

[miskatonicstudio]

That's the thing: the simple solution is to save the state of the scene ;) Saving a json or a config file with all the data picked manually from the whole game state seems very difficult, e.g. if an item was picked up, it has to be removed during initialization, if a door is closing slowly (this can be a part of a challenge/puzzle) then the state of the door also needs to be saved. If activating a generator lights up the generator screen, the computer screen, and portal lights, all of those scenes will have to react to the state of the generator included in the saved game. These are just the examples I can think of, I'm sure there are many more ;) It seems much easier to just "freeze" the entire scene and then bring it back ;)