potpackweighted

A tiny JavaScript library for packing 2D rectangles into a near-square container with priority based on a weight provided, which is useful for generating CSS sprites and WebGL textures. Similar to shelf-pack, but static (you can't add items once a layout is generated), and aims for maximal space utilization.

A variation of algorithms used in rectpack2D and bin-pack, which are in turn based on this article by Blackpawn.

Example usage

import potpackweighted from 'potpackweighted';

const boxes = [
    {w: 300, h: 50, weight:9},
    {w: 100, h: 200, weight:0},
    ...
];

const {w, h, fill} = potpack(boxes);
// w and h are resulting container's width and height;
// weight increases how close to the top left the box will be placed 
// fill is the space utilization value (0 to 1), higher is better

// potpack mutates the boxes array: it's sorted by weight and then height,
// and box objects are augmented with x, y coordinates:
boxes[0]; // {w: 300, h: 50, weight:9, x: 100, y: 0}
boxes[1]; // {w: 100, h: 200, weight: 0, x: 0,   y: 0}

Install

Install with NPM (npm install potpackweighted) or Yarn (yarn add potpackweighted), then:

// import as an ES module
import potpackweighted from 'potpackweighted';

// or require in Node / Browserify
const potpackweighted = require('potpackweighted');

Or use a browser build directly:

<script src="https://unpkg.com/potpackweighted@1.0.2/index.js"></script>