I'm trying to figure out how to determine the background overlay position. This little bit of code here: that helps you line up these two image types: Allowing the artwork and the functioning ship space to line up perfectly, giving the appearance that you are actually in the ship. Is there any way to determine it, or are you just kept guessing through repeatedly loading up the game and figuring out through trial and error??
I'd guess it's the position of the lower left corner of the overlay relative to the lower left corner of the blockmap, measured in tile spaces (thus the .625s, increments of 1/8 block aka a pixel)