805 karma · joined May 28, 2014
1) Store all actions by a user as as an array of add/remove commands (where a change is remove+add).
2) Whenever you need to re-render take the cached version from the last render and perform the new add/remove commands that happened since the last render.
3) Cache the result for the next render and repeat.
The "pictures" you're allowed to use (sprites that aren't the map, objects or system UI), must be explicitly set so if you want to render an integer as a picture you need 10 if statements per digit to select the right image. This has been resolved in re-release on Steam/etc, and also originally could be worked around using Cherry's PicPointer patch (which my project would've been impossible without).
The funny thing is that I implemented all the mechanics but burnt out on the pixel art, and I can't see myself wanting to grind that out. The game has 700+ scenes!
I think this project is neat from a preservation perspective, but there are so many limitations to its target engine that you will quickly bump into if you try to make anything that even approaches the quality of a real SNES RPG.
You're much better off using one of the later gen engines that uses JavaScript (probably whatever the very latest is).
I usually recommend SourceTree to them, not because it's particularly amazing, but it does enough while not breaking repos (as often).