Or is there a script already?

There's a script for autosave on smallg's thread.

I believe its just SaveGame()

I'd trigger it with how far the player gets into the map. You could do it with a timer too. Many different methods.

I think it's a bit more than that, there's a variable in it somewhere to choose the slot that the game is saved under.

I think it should be added to the Checkpoint script if it isn't already in there.

A most emphatic NO. Whether or not a checkpoint does an autosave is entirely the responsibility of the game creator not the engine!

If you are creating a game you are responsible for how that game functions in regard to the flow of the action for the player, this include whether or not the game is saved at specific trigger points or on a time played basis or even whether to allow the player to decide when to save their progress, the engine should remain completely agnostic in this regard.

Maybe one of the parameters available to the checkpoint 'zone' should be an 'autosave' parameter, but even if it were how does the engine know what exactly to save? Only the game creator knows what needs to be saved at any point in the game!

@AmenMoses
Of course. I mean the “possibility” of AutoSave, not a forced one.

I’m looking for a Lua command or a Checkpoint parameter for that.

The problem still remains of what to save, the engine can't know what is important and what is not.

I've been toying with the idea of a save-game Lua module for a while now but haven't started it yet (got distracted by the GitHub revolution ). The basic idea is to have scripts register their persistent data with the module and specify save triggers, either periodically or on player death/level change etc. The module would then save the registered data and reload it at the appropriate point. For example my pickuppables script would register the data structure it uses to store details about what the player has previously carried and which objects can no longer be carried (because they have served their purpose already) then if the player saves the game and reloads later this data is restored by the module prior to the pickuppables script initialisation.

Well that's the idea anyhow, not quite worked out all the implementation details yet though.

“What to save”?

Well, the entire game just like it was a manual save, obviously.
Something like reserving a slot for auosaved games.

GG already has a save system so just save the same as it does... I.e. anything with g_
Otherwise you will just cause more confusion when your checkpoints save more than the actual save system.

It would be nice to see parameters in the win zone and checkpoint zone markers for saving though... Maybe in a future update.

P.s. it's really quite simple to convert my auto save winzone script to a checkpoint too, just exchange the command to finish the level with the checkpoint command.

a global variable needs to be created that defines what map you are on. When you "auto-save" it saves all global variables. When you load an auto save it check the global variable for what map you should be on then loads a fresh one. Enemies and all that may reappear but not if you have them all checking for various global variables you may have created.

I might poke at this someday. Might require a bit of a load/save menu rehaul, or addition of an auto save/load.