Add visual novel like interface with save/load

[Fabian Maurer]

Especially for longer scripts it would be useful to have a simple to use save/load function. By saving variables and separating the story into functions, you can already implement it, but that's very limited and you for example can't quit anytime. And while you can create a line-perfect save function (see Inter Astra's DEngine), it's messy at best.

The best idea would be to handle the state in MT itself, that would give even inexperienced script writers easy access to saving.

I imagine it like this: When pressing Esc, the conversation doesn't quit directly, but shows a menu like continue/save/load/quit.

[Fabian Maurer]

Biggest issue I see with that: What happens if the user loads a save file, but the script is updated and thus different to the one used to make the save? Where should we resume if the line we saved at belonged to a part that got removed, for example?

I currently don't know yet, and the easiest "solution" would be to just fall back to the beginning of the current function. And if that got removed, the save can't be loaded. I don't know how other engines handle those cases, it seems like a tough problem. If someone has an idea, please tell me.

[mezzodrinker]

Maybe add a Load function that accepts a parameter? Not sure how to actually implement that, though. Would require some sort of Save function as well...