Adding a new map locations
Map locations can be added to the game in JSON. I’m not a maps guy, so I’m mostly going to point people to the docs and offer some advice. Also, lots of people figure out how to add new locations so it may not be too difficult.
A map location is defined across multiple files.
- The basic map, including monsters, NPCs, vehicles, traps, and items, is defined in a file in data/json/mapgen/ . data/json/mapgen/fire_station.json is the fire station, for instance, and it’s a good reference because it’s a moderately complicated, single tile design that only has one variant so you can look at the JSON and compare it to the game and make sense of it.
- Maps can have their palettes defined in the mapgen/ JSON file, or in a separate file that is customarily stored in data/json/mapgen_palettes/
- One or more maps can be collected into an overmap special, defined in data/json/overmap/specials.json. The JSON objects in this file control how a map spawns, where it is relation to a city, etc.
- data/json/overmap_connections.json and data/json/overmap_terrain.json also deal with mapgen, but frankly I don’t understand how and you should not mess with them absent better information.
The main document for mapgen is https://github.com/CleverRaven/Cataclysm-DDA/blob/master/doc/MAPGEN.md. It’s a little confusing at places, but you can basically ignore the sections on LUA and focus on the JSON sections.
More on data/json/specials.json
-
"sym"represents the symbol used. You can look at other mapgen entries to match up ‘correct’ symbols. -
"color"is the color. -
"see_cost"determines how far away you can spot the location, though I’m not 100% on how it works. I think you have a maximum number of tile-equivalents you can see, and a tile with a higher “see_cost” counts as more tile-equivalents. -
"mon_density"affects the density of creatures you place in your mapgen entry. -
"flags"are special tags that have particular effects. For example, I believe the flag “SIDEWALK” will attempt to attach your location to a sidewalk. So if you’re making a house or readily accessible building, you want that flag. -
Important Note! There is an
"occurrences"field in each object in specials.json, which is a list of two numbers like this[ 0, 4 ]. The first number is the minimum number of times your special will appear on an overmap, and the correct value for that number is always 0. Not 1, not 2, not 4, it should be 0. I know your overmap special is extra special and you want to see it on every map, but nevertheless, the minimum number of occurrences is 0.
The second number is the maximum number of occurrences, which can be any number greater than 0.