Monday 3 October 2022

The Xevious Map starts to reveal its secrets!

A little more RE'ing and a lot more eye candy to come in the next few sessions!

More work on decoding the area object tables; I can (syntax) parse the complete tables even though I have only identified (I think) the EVEZOO Easter Egg, ground-based objects and the bonus flags. And for the abovementioned ground-based objects I know the x-coordinate of the sprite now.

Between some dynamic analysis and the MAME source, I've managed to create a new tool to extract each of the area maps from the ROMs and save them as bitmap files. And as the maps are generated row-by-row, I now parse the object tables. It should be trivial to (also) produce the global map.

With a quick 'n' dirty hack I can show the location of the Sol Towers with a red square.


Area 6 with Sol Tower locations in red.

This will get built on as I further RE the tables and ultimately I should be able to show all the objects. I'll update the tool to show the correct sprites for the currently-identified objects, then return to the task of RE'ing the rest of the code.

Some game trivia; there are a total of 46 Sol Towers in the game, many more than were originally documented in the StrategyWiki Walkthough, and even one more than documented in SPM's comprehensive Xevious Secrets YouTube video (in area 6, as shown above!) I knew most of them when I played back in the day, but looking at the video/maps now, I'm sure there's a few that I didn't in fact know about!

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