flood-fill

A simple 2D flood fill for use with ndarrays.

You could use this to re-implement Microsoft Paint's bucket fill in JavaScript, or in procedural dungeon generation to identify disconnected rooms.

Installation

npm install flood-fill

Usage

require('flood-fill')(ndarray, x, y, fillValue)

Fills the array with fillValue, starting from the position at (x, y).

This will also return an object with some very basic metrics for you to use:

• area: the total amount of cells filled.
• hi: the highest x/y positions filled.
• lo: the lowest x/y positions filled.

Note that hi and lo may not have been filled themselves.

var fill = require('flood-fill')
var zero = require('zeros')

var grid = zero([50, 50])
var height = grid.shape[1]
var width = grid.shape[0]

for (var x = 0; x < 50; x += 1) grid.set(x, 10, 1)
for (var x = 0; x < 50; x += 1) grid.set(x, 21, 1)
for (var y = 0; y < 50; y += 1) grid.set(10, y, 1)
for (var y = 0; y < 50; y += 1) grid.set(22, y, 1)

fill(grid, 30, 19, 2)

for (var y = 0; y < height; y += 1) {
  for (var x = 0; x < width; x += 1) {
    process.stdout.write(grid.get(x, y) ? '#' : ' ')
  }
  console.log()
}