Research: Editing the town map in Platinum

[Wavee]

ive spent some time figuring out how the town map works in platinum. this is not about changing the graphics but instead the location of blocks and cities on the map. Blocks are the tiles on the map that are "active", meaning that they display the maps headers name bellow the map, determine the guidemap data, and make them selectableto fly to.

this data is for platinum. the overlay and offsets are probably different in diamond and pearl. everything else should otherwise be the same.

Anyways:

Spoiler:

data starts at offeset 04 in tmap_block

first 2 bytes are x coordinate for map block
second 2 bytes are y coordinate for map block
next 2 bytes are if the direction on the guidemap is shown
next 2 bytes determines which direction image to use on the guidemap
next 2 is the the description the guide map uses
next 2 bytes are FF FF
next 12 bytes are unknown. Theyre the exact same for every block of data so they might just be unused

a block is 18 bytes (HEX) long

tmap_flags has to do with areas that only show up on the map once you visit them. I havent looked into this too much yet. Zeroing out the data around offset 190 seems to just disable these.

starting at offest 2458 in overlay 80 is the x y coordinates of the city locations on the map

each section is 14 bytes (HEX) long, and is made of 5 4 byte subsections. its layed out as such:
mapid
The sections order in the list? (probably not important)
the city type (1 tile town, 2 tile town, 4 tile city, etc)
x coordinate
y coordinate

the x and y coordinates are by pixel rather than by tile

 

[Platinum Lucario]

I should note that most of the Town Map data relies heavily on file 0 of map_matrix.narc, since most of the data is dependent on it (except for indoor locations or maps that use a different map matrix file in the archive). So most of the Town Map changes can be made though modifying file 0 in map_matrix.narc

 

[Wavee]

for anybody wants to edit the rcsn tilemaps, the formats are the exact same as gba tilemaps. You can remove the header from the exported file (the first 24 HEX bytes) and load into any gba tilemap editor. I've tried it with Tilemap Creator and NTME.