Quote:Should a script engine really cover everything, including things like window size etc?

A scripting language should cover whatever you want to USE it for.

If you want it so you can effectively write an entire game from your own language without ever touching DX/C/C++/VB/Whatever, then yes, something low-level like window-size is important.

If you only want to use it to script in-game sequences (e.g. NPC's and/or set-pieces of action) then low-level stuff like window-size is probably not that important.

Given this is your 3rd engine, I'd recommend you decide EXACTLY what you want it to be able to do before simply declaring "everything". A scripting language that covers everything is probably going to converge quite quickly on a near-complete language itself, which isn't that easy to implement. A cut-down/restricted scripting language for specific usage is likely to be easier to develop.

hth
Jack

If you want to write everything in a scripting language, why not just dispense with writing the language, and write the game in something like Python?