Comprehensive pathfinding library for grid based games
The aim of this project is to provide a path-finding library that can be easily incorporated into web games. It may run on Node.js or the browser.
It comes along with an online demo to show how the algorithms execute. (The pathfinding speed is slowed down in the demo)
There is new documentation being written for PathFinding.js. You can read it here. Note that this is in very early stages and far from complete so keep your eyes open for mistakes and don't hesitate to open a pull request in case you find one.
If you want to use it in Node.js, you may install it via
npm install pathfinding
Then, in your program:
var PF = require'pathfinding';
Basic Usage section below for usage details.
If you have bower installed then you can install it with the following command:
bower install pathfinding
By default bower will install pathfinding under the bower_components folder, so to include it in your page do something like:
You can also grab a release from the Releases Page if you don't use bower.
To build a grid-map of width 5 and height 3:
var grid = 5 3;
By default, all the nodes in the grid will be able to be walked through.
To set whether a node at a given coordinate is walkable or not, use the
For example, to set the node at (0, 1) to be un-walkable, where 0 is the x coordinate (from left to right), and 1 is the y coordinate (from up to down):
gridsetWalkableAt0 1 false;
You may also pass in a matrix while instantiating the
It will initiate all the nodes in the grid with the same walkability indicated by the matrix.
0 for walkable while 1 for blocked.
var matrix =0 0 0 1 01 0 0 0 10 0 1 0 0;var grid = matrix;
Currently there are 10 path-finders bundled in this library, namely:
Bi for the last four finders in the above list stands for the bi-directional searching strategy.
Also, Note that only the finders with trailing asterisks are guaranteed to find the shortest path.
To build a path-finder, say, the
var finder = ;
To find a path from (1, 2) to (4, 2), (Note: both the start point and end point should be walkable):
var path = finderfindPath1 2 4 2 grid;
path will be an array of coordinates including both the start and end positions.
matrix defined previously, the
path will be:
1 2 1 1 2 1 3 1 3 2 4 2
Be aware that
grid will be modified in each path-finding, and will not be usable afterwards. If you want to use a single grid multiple times, create a clone for it before calling
var gridBackup = gridclone;
When instantiating path-finders, you may pass in additional parameters to indicate which specific strategies to use.
For all path-finders, you may indicate whether diagonal movement is allowed. The default value is
false, which means that the path can only go orthogonally.
In order to enable diagonal movement:
var finder =allowDiagonal: true;
When diagonal movement is enabled, you might want to prevent the path from touching the corners of the occupied grid blocks. This is usually desirable if the objects using the path have physical width and can also move between the grid cells.
To enable the corner crossing prevention:
var finder =allowDiagonal: truedontCrossCorners: true;
dontCrossCorners only makes sense when
allowDiagonal is also used. Currently all algorithms except
JumpPointFinder support this feature.
BestFirstFinder and all their
Bi relatives, you may indicate which heuristic function to use.
The predefined heuristics are
To use the chebyshev heuristic:
var finder =heuristic: PFHeuristicchebyshev;
To build a
BestFirstFinder with diagonal movement allowed and a custom heuristic function:
var finder =allowDiagonal: truereturn Mathmindx dy;;
To smoothen the path, you may use
PF.Util.smoothenPath. This routine will return
a new path with the original one unmodified.
var newPath = PFUtilsmoothenPathgrid path;
Note that the new path will be compressed as well, i.e. if the original path is
[[0, 1], [0, 2], [0, 3], [0, 4]], then the new path will be
[[0, 1], [0, 4]].
To just compress a path without smoothing it, you may use
var newPath = PFUtilcompressPathpath;
To expand the compressed path like
[[0, 1], [0, 4]] back to
[[0, 1], [0, 2], [0, 3], [0, 4]],
you may use
var newPath = PFUtilexpandPathpath;
. |-- lib # browser distribution |-- src # source code (algorithms only) |-- test # test scripts |-- utils # build scripts |-- benchmark # benchmarks `-- visual # visualization
Make sure you have
node.js installed, then use
npm to install the dependencies:
npm install -d
The build system uses gulp, so make sure you have it installed:
npm install -d -g gulp
To build the browser distribution:
npm install -d -g mocha
Then run the tests:
To run the benchmarks:
Or if you are feeling lazy, the default gulp task does everything(except running the benchmarks):
© 2011-2012 Xueqiao Xu <email@example.com>
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