FullScreenPokemon/docs/map-spawning.md

Map Spawning

Individual sections of the overworld are stored as separate maps under src/creators/mapLibrary. Areas register their neighbors by placing an AreaSpawner Actor on the border between the two areas:

creation: [
    { actor: "AreaSpawner", width: 608, height: 544, map: "Route 1", area: "Land", direction: 0 },
    // ...
],

Once spawned into the game map, that AreaSpawner will kill itself and place an AreaGate on the border. That AreaGate, when collided with, sets the active area and starts a new audio theme.

Active Areas

AreaSpawner's core logic only has awareness of the originally spawned area. Use FSP.mapScreener.activeArea to get the currently active area.