pulsar-pathfinding

pulsar-pathfinding is a TypeScript implementation of the Greedy Best-First pathfinding algorithm.

README IN PROGRESS

Install

Install with npm:

npm install pulsar-pathfinding

Examples

NOTE: All pictures below are captured from debug mode. You may use the results in any way, graphical or not.

1: Creating the Grid.

This represents an abstract mathematical graph of nodes implemented as NavigatorTile. It may have any width and height as a constructor argument, and it defaults to {width: 10, height: 10}.

import { Grid } from 'pulsar-pathfinding';
const grid: Grid = new Grid({width: 10, height: 10});

2: Accessing NavigatorTile on the grid

NavigatorTile are stored by the Grid and can be accessed either by grid coordinates

const begin: NavigatorTile = grid.findTile({x: 0, y: 0});
const end: NavigatorTile = grid.findTile({x: 9, y: 9});

or randomly:

const randomTile: NavigatorTile = grid.randomTile();         // any possible tile
const randomFreeTile: NavigatorTile = grid.randomFreeTile(); // only tiles that are not obstacles

3: Creating Obstacles.

Obstacles can be added and removed with the add(tile), remove(tile) methods on grid.obstacles

  const tile: NavigatorTile = grid.findTile({x: 0, y: 0});
  grid.obstacles.add(tile); // tile.isObstacle = true
  grid.obstacles.remove(tile); // tile.isObstacle = false

4: Creating a Navigator.

This is the object that traverses the Grid you created. It requires the following as constructor arguments: a grid, a begin tile and an end tile.

import { Navigator } from 'pulsar-pathfinding';

const grid: Grid = new Grid({width: 10, height: 10});

const begin: NavigatorTile = grid.findTile({x: 1, y: 1});
const end: NavigatorTile = grid.findTile({x: 9, y: 9});

const navigator: Navigator = new Navigator({grid, begin, end});

Optionally, Navigator may receive two callback functions, in the form of onExplore and onComplete.
and an optional maxSteps parameter.

const navigator: Navigator = new Navigator({
  grid,
  begin,
  end,
  onExplore: (NavigatorTile) => {
    // NavigatorTile
  },
  onComplete: (NavigatorTileArray) => {
    // NavigatorTile[]
  },
  maxSteps: 10,
});

onExplore(NavigatorTile) will be called for each NavigatorTile that the Navigator explores
onComplete(NavigatorTile[]) will be called with the array of NavigatorTiles in the shortest path that the Navigator found

The Navigator explores multiple possible tiles until it finds the shortest route.

If No path is found, onComplete will return an empty Array

Pictured below: an artificially slowed down demonstration of callbacks.
Blue tiles are colored using onExplore and green ones using onComplete.

Once the navigator is created, we now call the start method.
The resulting path (a NavigatorTile array), is stored in the path property.

navigator.start();
draw(navigator.path);