Asumeohr save system POC

Designing the two saving solutions considered for the Asumeohr video game ❤️

The two options considered are the following ones (I'll detail them later on).

• A SQLite database;
• Separate JSON files.

To demonstrate both systems, here's a brief explanation of what the piece of software will do. At startup, it'll ask the user what type of save system to use and it will load the "game" by creating the required instances via that system. Once loaded, it will output all it has loaded and terminate.

SQLite database implementation

On this implementation, the user data, as well as the game assets are saved into a one-file database. The call to the interface method LoadDataAndAssets() will pull everything out of the database, making no distinction between both.
All the data gathered will be stored in the cache, except global variables that will be instantiated as singletons.

JSON serialization implementation

Here, the user data and the assets will be clearly separated, each in different sub-folders. Of course, both will be loaded when calling LoadDataAndAssets() method, though the separation will be way clearer when it comes to the implementation. The use of a cache system may be discussed in this implementation, but to make the code easier to compare with the previous implementation, it will be used as well to manage the memory. In a real implementation, we could simply load what is required at the very moment when starting the game, and continuously keep loading things following the user's movements and actions.

Infrastructure & prototype details

Of course, to make the tests interesting, we need to gather some data to load and store. And to gather this data, we have to create classes. Here's what this POC will come up with:

• a Player class, with attributes such as the current map, its x and y axis positions, ...
• a Map class, with its dimensions, its sprite, ...
• an Item class, with 2 sub-classes: Weapon and Equipment
• a Skill class, with a name, an icon, a description, ... The global variables will be stored in the main class.

Total amount of data to load

• JSON: 1.4MB
• SQLITE: 1.4MB (size of the database, so probably a bit less).

Actions available once loaded

Once all the data from the desired save is loaded, the application turns into a console, letting you enter commands to change the data and act onto it. Here's the list of commands, with a brief description and the details of their arguments.

NOTE: The actions you may perform won't be saved automatically. You need to use saving commands to serve that purpose.

NOTE: The creation of new saves is not supported yet. Saving an already created save to another name is possible though.

Command	Description	Arguments
save	This command will save the game currently loaded. Without arguments, it will save it into the same save it was loaded from. Specifying a savename allows to save it as another save. Of course, when the save is new, the savename becomes mandatory.	[savename:string]
save_exit	This command simply stops the programme immediately after saving. All other specificities are the same as the previous one.	[savename:string]
exit	This command allows exiting the programme in a clean way.	N/A
give	Adds an item to the user's inventory. The item can be a weapon or an equipment as well. The item id must be specified, but the quantity is optional (defaults at 1)	<item_id:int> [quantity:int]
drop	Removes an item from the user's inventory. The item cannot be an equipped weapon or equipment. Unlike the give command, it won't be identified via its id, but via the 1-based inventory index (1 for the first slot, n for the nth ...). It is also possible to specify a quantity to drop, but the command will be rejected if it is too high.	<inventory_slot:int> [quantity:int]
equip	Equips a weapon or an equipment that is in the user's inventory. If the user is already equipped with a weapon, the command will fail. However there is no restriction for equipments.	<inventory_slot:int>
unequip	Un-equips a weapon or an equipment. Without arguments, this command will un-equip the user's weapon. The equipment_slot argument allows selecting the equipment to remove. Un-equipped items will be added to the user's inventory.	[equipment_slot:int]
learn	Learns the user a new skill. The skill will be identified via its id.	<skill_id:int>
forget	Lets the user forget about a skill they previously learned. The skill will be identified via its 1-based user skill index (1 for the first skill, n for the nth ...).	<skill_slot:int>
move	Moves the player in the given direction. The direction argument may be one of ["up" ; "right" ; "down" ; "left"]. By default, the amount of squares traveled will be 1, but it is specifiable. It is also possible to specify "max" instead of an actual value, to move in the same direction until we reach the map border. If the given value is too high, the command will fail and the player will stay at the same place.	<direction:string> [amount:int|"max"]
teleport	Teleports the player to the given destination. Of course, the destination may be another map, identified via its asset name. X and Y coordinates have to be specified, and correct, otherwise the teleportation will be cancelled.	[map_name:string] <pos_x:int> <pos_y:int>
set_difficulty	Modifies the game difficulty. Possible values ranges from Easy (0), Hard (1), Extremely hard (2) and Hell (3)	<difficulty:int>
toggle_chose_class	Toggles the value of the ChoseClass global variable. You may use the display commands to check its value.	N/A
progress	Edits the progress variables states. Possible states value ranges from Not yet (0), Ongoing (1) and Done (2)	<variable_name:string> <state:int>
display	Prints the entire game object to the terminal. (this is what is done at startup, once every asset and data are loaded).	N/A
display_player	Prints the entire player object to the terminal.	N/A
display_map_cache	Prints the entire map cache.	N/A
display_weapon	Prints the player's current weapon.	N/A
display_equipments	Prints the player's current equipments.	N/A
display_inventory	Prints the player's current inventory.	N/A
display_skills	Prints the player's current skills.	N/A
display_map	Prints the player's current map.	N/A

Version notes:

SQLite: 3.31.1 (released on 2020-01-27)
g++: 9.4.0 (released in 2019)
nlohmann/json: 3.11.2 (released on 2022-08-12)
libmagick++-dev: 6.9.10.23 (released on 2023-03-15)
sqlite_modern_cpp: latest (cloned from the repo)