This is a custom pathfinder for use in Screeps. It has
support for custom cost functions (see path-room-data.js), can create paths
that span several rooms, and is a good deal faster than the built-in pathfinder
as well. Under the hood it's using a modified version of jump point search...
JPS by design only works on uniform-cost grids, but Screeps' grids are weighted
(plain, swamp, and road all cause different values of fatigue) so we need to
modify the original algorithm a little bit.
The code itself is fairly well documented, but you won't find any API documentation except for looking at the code yourself.
Getting started:
let path = require('path_');
let WorldPosition = path.WorldPosition;
path.find(
WorldPosition(Game.creeps.John.pos),
{ target: WorldPosition(Game.spawns.Spawn1.pos) }
);This pathfinder uses a replacement for RoomPosition called WorldPosition.
Instead of tracking positions by coordinates and a room name, WorldPosition
unifies the entire world map into a continuous coordinate plane. This allows us
to easily calculate the distance between two positions when they aren't in the
same room. You can convert a RoomPosition into a WorldPosition via
WorldPosition(rp) and a WorldPosition back via wp.toRoomPosition().
Returned from find is a PathInfo object which keeps around some extra data
about the path, like where the roads and swamps are. See path-info.js.
The first time you create a path you will need to have access to all the rooms
it touches, but after the pathfinder has seen a room it will remember its
terrain and you can search for paths through rooms in which you control no
creeps or structures. This data is all stashed in Memory.terrain. See
TerrainData in path-room-data.js for more information about that.
You can specify multiple targets by using the targets option parameter, or try
findNearest for a replacement of RoomPosition.findClosestByPath with the
added bonus of returning the path to whatever it found.